qing li, md, phd nippon medical school tokyo, japan · what is a forest? in 2000, the forest...
TRANSCRIPT
Does nature affect human immune function
Qing Li MD PhDNippon Medical School
Tokyo Japan
May 27 2011
What are natural environments(green spaces)
There are numerous definitions of natural environments (also called green spaces)
The Centres for Disease Control define them as ldquoopen undeveloped land with natural vegetationrdquo parks forests playing fields river corridors and the like
Nature is defined as bdquothe environment in which organisms or their biotopes expressly manifest themselves In addition to nature reserves this also includes farmland production forest urban green spaces and back gardens‟ (Health Council of the Netherlands 2004)
What is a forest
In 2000 the Forest Resources Assessment (FRA) 2000 project defined the ldquoforestrdquo as follows
Forest includes natural forests and forest plantations
It is used to refer to land with a tree canopy cover of more than 10 percent and area of more than 05 ha (hectare)
Forests are determined both by the presence of trees and the absence of other predominant land uses
The trees should be able to reach a minimum height of 5 m
httpwwwfaoorgDOCREP004Y1997Ey1997e1mhtm
What is a forest in Japan
In Japan forest is used to refer to land with a tree canopy cover of more than 30 percent and area of more than 03 ha (hectare)
The trees should be able to reach a minimum height of 5 m with a width of more than 20 m
The forests include Japanese cypress (Chamaecyparisobtuse Hinoki in Japanese) Japanese cedar (Cryptomeria Sugi in Japanese) Japanese beech Japanese white birch Japanese oak and so on
httpwwwenvgojpearthondankasantei_k18_02mat02_1pdf
Why do people love (like) forests
The forest environment has been enjoyed by humans for a long time because of
The quiet atmosphere
The beautiful scenery
The mild climate
The clean fresh air in the forest
What is a forest bathing trip (Shinrin-yoku)
A forest bathing trip is a short leisurely trip visiting a forest called Shinrinyoku in Japanese which is similar to a natural aromatherapy
The purpose of forest bathing trip is relaxation and recreation by breathing in volatile substances from trees called phytoncides such as alpha-pinene and limonene
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
What are natural environments(green spaces)
There are numerous definitions of natural environments (also called green spaces)
The Centres for Disease Control define them as ldquoopen undeveloped land with natural vegetationrdquo parks forests playing fields river corridors and the like
Nature is defined as bdquothe environment in which organisms or their biotopes expressly manifest themselves In addition to nature reserves this also includes farmland production forest urban green spaces and back gardens‟ (Health Council of the Netherlands 2004)
What is a forest
In 2000 the Forest Resources Assessment (FRA) 2000 project defined the ldquoforestrdquo as follows
Forest includes natural forests and forest plantations
It is used to refer to land with a tree canopy cover of more than 10 percent and area of more than 05 ha (hectare)
Forests are determined both by the presence of trees and the absence of other predominant land uses
The trees should be able to reach a minimum height of 5 m
httpwwwfaoorgDOCREP004Y1997Ey1997e1mhtm
What is a forest in Japan
In Japan forest is used to refer to land with a tree canopy cover of more than 30 percent and area of more than 03 ha (hectare)
The trees should be able to reach a minimum height of 5 m with a width of more than 20 m
The forests include Japanese cypress (Chamaecyparisobtuse Hinoki in Japanese) Japanese cedar (Cryptomeria Sugi in Japanese) Japanese beech Japanese white birch Japanese oak and so on
httpwwwenvgojpearthondankasantei_k18_02mat02_1pdf
Why do people love (like) forests
The forest environment has been enjoyed by humans for a long time because of
The quiet atmosphere
The beautiful scenery
The mild climate
The clean fresh air in the forest
What is a forest bathing trip (Shinrin-yoku)
A forest bathing trip is a short leisurely trip visiting a forest called Shinrinyoku in Japanese which is similar to a natural aromatherapy
The purpose of forest bathing trip is relaxation and recreation by breathing in volatile substances from trees called phytoncides such as alpha-pinene and limonene
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
What is a forest
In 2000 the Forest Resources Assessment (FRA) 2000 project defined the ldquoforestrdquo as follows
Forest includes natural forests and forest plantations
It is used to refer to land with a tree canopy cover of more than 10 percent and area of more than 05 ha (hectare)
Forests are determined both by the presence of trees and the absence of other predominant land uses
The trees should be able to reach a minimum height of 5 m
httpwwwfaoorgDOCREP004Y1997Ey1997e1mhtm
What is a forest in Japan
In Japan forest is used to refer to land with a tree canopy cover of more than 30 percent and area of more than 03 ha (hectare)
The trees should be able to reach a minimum height of 5 m with a width of more than 20 m
The forests include Japanese cypress (Chamaecyparisobtuse Hinoki in Japanese) Japanese cedar (Cryptomeria Sugi in Japanese) Japanese beech Japanese white birch Japanese oak and so on
httpwwwenvgojpearthondankasantei_k18_02mat02_1pdf
Why do people love (like) forests
The forest environment has been enjoyed by humans for a long time because of
The quiet atmosphere
The beautiful scenery
The mild climate
The clean fresh air in the forest
What is a forest bathing trip (Shinrin-yoku)
A forest bathing trip is a short leisurely trip visiting a forest called Shinrinyoku in Japanese which is similar to a natural aromatherapy
The purpose of forest bathing trip is relaxation and recreation by breathing in volatile substances from trees called phytoncides such as alpha-pinene and limonene
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
What is a forest in Japan
In Japan forest is used to refer to land with a tree canopy cover of more than 30 percent and area of more than 03 ha (hectare)
The trees should be able to reach a minimum height of 5 m with a width of more than 20 m
The forests include Japanese cypress (Chamaecyparisobtuse Hinoki in Japanese) Japanese cedar (Cryptomeria Sugi in Japanese) Japanese beech Japanese white birch Japanese oak and so on
httpwwwenvgojpearthondankasantei_k18_02mat02_1pdf
Why do people love (like) forests
The forest environment has been enjoyed by humans for a long time because of
The quiet atmosphere
The beautiful scenery
The mild climate
The clean fresh air in the forest
What is a forest bathing trip (Shinrin-yoku)
A forest bathing trip is a short leisurely trip visiting a forest called Shinrinyoku in Japanese which is similar to a natural aromatherapy
The purpose of forest bathing trip is relaxation and recreation by breathing in volatile substances from trees called phytoncides such as alpha-pinene and limonene
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Why do people love (like) forests
The forest environment has been enjoyed by humans for a long time because of
The quiet atmosphere
The beautiful scenery
The mild climate
The clean fresh air in the forest
What is a forest bathing trip (Shinrin-yoku)
A forest bathing trip is a short leisurely trip visiting a forest called Shinrinyoku in Japanese which is similar to a natural aromatherapy
The purpose of forest bathing trip is relaxation and recreation by breathing in volatile substances from trees called phytoncides such as alpha-pinene and limonene
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
What is a forest bathing trip (Shinrin-yoku)
A forest bathing trip is a short leisurely trip visiting a forest called Shinrinyoku in Japanese which is similar to a natural aromatherapy
The purpose of forest bathing trip is relaxation and recreation by breathing in volatile substances from trees called phytoncides such as alpha-pinene and limonene
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest bathing trips (Shinrin-yoku) in Japan
Incorporating forest bathing trips into a good lifestyle was first proposed in 1982 by the Forest Agency of Japan and the first kick off meeting was held at Akasawa in Nagano prefecture located in northwestern Japan
Now it has become a useful and popular relaxation and stress management activity in Japan
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest environment and Immune function
It is well known that immune system including natural killer (NK) cells plays an important role in defense against bacteria viruses and tumors
It is also well known that stress inhibits immune function
Forest environment may reduce stress
Therefore we speculate that forest environment may have beneficial effect on immune function by reducing stress
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Natural killer (NK)
Blood
darr
Red blood cells White blood cells platelet
darr
Granulocytes Lymphocytes Macrophages
darr
T cells NK cells B cells
(Immune cells)
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Relationship between incidence rate of cancer and NK activity
Kazue Imai et alLancet 2000 356 1795ndash99Subjects 3625Periods of follow-up11 years
People with lower NK activity
People with lower NK activity
People with higher NK activity
People with higher NK activity
Incid
ence
rare o
f Can
cer
Incid
ence
rare o
f Can
cer
Males
Females
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
NK
Granzymes Perforin Granulysin
Apoptosis
GrA
GrB
Gr3K
GrH
GrM
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of NK-induced apoptosis
(Tumor cell)
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Cancers and NK cellsCancer cells rarrCriminals
NK cellsrarrPolicemen
Policemen>>CriminalsrarrSafepeace
NK cells >>Cancers rarrHealth
Criminals>>Policemen rarrInsecurity
Cancer cells>>NK cellsrarrCancer
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Todayrsquos topics
1 Effect of 2-night3-day trips to forest parks on human immune function
2 Effect of a day trip to a forest park on human immune function
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Objective
To investigate the effect of the forest
environment on human immune function
We investigated NK (natural killer)
activity the numbers of NK cells and
intracellular levels of anti-cancer proteins
such as perforin granzyme and
granulysin in human lymphocytes during
visiting to forest fields
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Subjects and schedule
1 Subjects ① and ② 12 healthy male subjects aged 37-55 years (mean 431plusmn61) ③ 13 healthy female nurses aged 25-43 years (mean 288plusmn46)
2 Schedule Three-daytwo-night trips in the beginning of Sept at 3 different forest fields
3 On day 1 subjects departed to forest fields in the morning then walked for 25km during 2hs in the afternoon at a forest field
4 On day 2 subjects walked for 25km during 2hs in the morning and afternoon respectively at two different forest fields
5 On day 3 the subjects finished the trip and returned to Tokyo after blood was drawn and a questionnaire survey was completed
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Subjects were walking in a forest(Japanese oak Japanese white birch Bamboo grass)
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Japanese cypress
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Schedule for taking blood samples
Blood samples were taken at 800 am in all experiments
Working day Before the trip at 800 am
Day 2 of the trip at 800 am
Day 3 of the trip at 800 am
Day 7 after the trip at 800 am
Day 30 after the trip at 800 am
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Parameters
NK activity number of NK cells
Intracellular Perforin Granulysin Granzymes AampB
Estrogen progesterone in blood
Adrenaline and noradrenaline in urine (stress hormones)
POMS (Profile of Mood States)
Sleeping hours
Physical activity
Questionnaire for stress
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A forest visit significantly enhanceshuman NK activity in males
plt005 plt001 from before the trip plt005 from Day 1
Effect of a forest bath trip on human NK activity
0
10
20
30
40
Before Day 1 Day 2
NK
acti
vity
()
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest visits increased NK activity and this effect lasted for more than 7 days in both males and females
Male
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day30
NK
acti
vit
y (
)
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
35
Before Day 1 Day 2 Day 7 Day 30N
K a
cti
vit
y (
)
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A trip to a place without forest does notenhance human NK activity in malesEffect of a trip in a place without forest on NK activity
0
5
10
15
20
25
30
35
Before Day 1 Day 2
NK a
vtiv
ity (
)
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Question
Q Why do forest visits increase human NK activity
A1 The number of NK cells increaseduarr
A2 The intracellular anti-cancer proteins increaseduarr
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H100 101 102 103 104
FL2-H
Before the trip 1 day after trip 7 days after trip
6256 5161 4887 173201149
398039222827
NK cells
Tce
lls
Forest visit significantly increasedthe number of NK cells in males
Li et al J Biol Regul Homeost Agents 201024(2)157-65
In this subject the NK cells increased from 2827 to 3922 on day 1 and 3980 on day 7 after the trip
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest visit significantly increased the number of NK cells in males
plt001 significantly different from before the trip plt001 significantly
different from Day 1
0
200
400
600
800
1000
Before Day 1 Day 2
NK N
um
ber
ul
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest visits increased NK cells and this effect lasted for more than 7 days in both males and females
Male
0
100
200
300
400
500
600
Before Day 1 Day 2 Day 7 Day30
No
of
NK
cell
su
l
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
5
10
15
20
25
30
Before Day 1 Day 2 Day 7 Day 30N
K c
ells
()
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A forest visit significantly increased granulysin perforin granzyme AB-expressing lymphocytes
plt001 from before the trip $ plt001 from Day 1
0
200
400
600
800
1000
1200
1400
1600
1800
GRN Perforin GrA GrB
Num
ber
of c
ells
ul
Before
Day 1
Day 2
Li Q et al Int J Immunopathol Pharmacol 200720(2 Suppl 2)3-8
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest visits increased intracellular anti-cancer proteins and this effect lasted for more than 7 days in
both males and females
Male
0
10
20
30
40
50
60
70
Perforin GrA GrB GRN
Po
siti
ve r
ate(
)
Before
Day 1
Day 2
Day 7
Day30
plt005 plt001 from before the trip
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Female
0
10
20
30
40
50
60
Perforin GrA GrB GRN
Po
sit
ive r
ate
(
)
Before
Day 1
Day 2
Day 7
Day 30
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Factors affecting NK activity and the countermeasures
Circadian rhythm rarr Taking blood samples at the same time
Physical activity rarr Setting it at the same level
Alcohol drinking rarrAbstaining from drinking
(During the experiment)
Estrogen progesterone rarr Measuring it
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A forest visit decreased urinary adrenaline whereas a city tourist trip did not affect this
Forest bathing trip
0
1
2
3
4
5
6
Before Day 1 Day 2
plt005 from Before
ug
g
Cr
Li Q et al Int J Immunopathol Pharmacol 200821(1)117-27
City tourist trip
0
1
2
3
4
5
6
Before Day 1 Day 2
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A forest visit decreased urinary adrenaline and noradrenaline in
females
Urinary adrenaline
0
2
4
6
8
10
Before Day 1 Day 2
ug
g C
reati
nin
e
plt001 Li Q et al J Biol Regul Homeost Agents 200822(1)45-55
Urinary noradrenaline
0
20
40
60
80
100
Before Day 1 Day 2
ug
g C
reati
nin
e
68darr
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Forest bathing trips reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
POMS test Mean+SE (n=53)
0
10
20
30
40
50
60
Anxiety Depression Anger Vigour Fatigue Confusion
T S
core
s
Before After
plt001 significantly different from before Li Q et al Jpn J Hyg 63 (2) 412 2008
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Stress and immune response
StressorTension Anxiety
(Stress response)
Release of Stress hormones
Immune
functiondarr
Disturbance of autonomic nerves
ForestdarrReducing stressdarrRecover NK activity darrNK activity increased
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Question
It is not clear whether a day trip to a forest park also increases human NK activity
In the present study we addressed this question
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A day trip to a forest park
1 Subjects 12 healthy male subjects aged 34-53 years (mean 442plusmn60)
2 Schedule A day trip in the end of July to a forest park at Saitama prefecture located in the north of Tokyo Japan
3 The subjects walked for two hours each in the morning and afternoon for total of about 4 km in the forest park and then returned to Tokyo
4 A questionnaire of the Profile of Mood States (POMS) test was conducted before during and after the walking
5 Blood was sampled on the second day and on day 7 after the trip and 6 days prior to the trip as a control
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A day trip to a forest park
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A day trip to a forest park increases human natural killer (NK) activity and NK cells
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
100 101 102 103 104
FL1-H100 101 102 103 104
FL1-H
Before After
6064 44851849
858
2485
1645
T cells
Granzyme A
Effect of a day trip to a forest park on Granzyme A-expressing cells in lymphocytes
In this subject the total of Granzyme A-expressing cells increased from
2707 (1849+858) to 4130 (2485+1645) after the trip
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A day trip to a forest park increases the expression of anti-cancer proteins in lymphocytes
Perforin Granzyme A Granzyme B Granulysin
plt001
Li et al J Biol Regul Homeost Agents 201024(2)157-65
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
A day trip to a forest park reduces cortisol in serum
plt001 p=0053
Li et al J Biol Regul Homeost Agents 201024(2)157-65
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Concentration of volatile substances (phytoncides) in
the air of the forest park calculated as α-pinene (ngm3)
Kind of phytoncides
Quercus serrata
forest area
Pine forest
area
Isoprene 52916 98
Tricyclene 151 181
α-Pinene 700 2411
Camphene 124 203
β-Pinene 188 398
D-Limonene 109 222
Bornyl acetate 00 111
The concentration of phytoncides represents the mean concentrations of
each chemical between 930 am and 1530 pm with consecutive sampling
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
NK
Granzymes Perforin Granulysin
Apoptosis (cell death)rarrNK activity uarr
GrA
GrB
Ca++uarr K+darr
AIF Cyto-C
release
Mechanism of forest bathing-induced NK activity
(Tumor cell)
Forest bathing
Reduce Stress
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Conclusions
1 Forest visits significantly increase human NK activity in both males and females which was mediated by increases in the number of NK cells and the intracellular anti-cancer proteins
2 This effect lasted for more than 7 days even 30 days after the trips
rarrPreventive effect on cancers
3 Forest visits also significantly reduce the levels of urinary adrenaline and noradrenaline which are stress hormones
rarrStress management
4 Phytoncides from forests and relaxation may contribute to this effect
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Other effects
1 Forest visits significantly reduce blood pressure and blood glucose
rarrpreventive effects on hypertension diabetes and metabolic syndrome
2 Forest visits stabilize the activity of autonomic nerves by increasing the activity of parasympathetic nerves and decreasing the activity of sympathetic nerves
3 Forest visits reduce the scores of anxiety depression anger fatigue and confusion whereas increase the score of vigor
rarrpreventive effects on depression
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Fuji TV (News Speak) reported our research on forest medicine on
November 8 2005
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
The Japan Times reported our research on forest medicine on 200852
Friday May 2 2008
Forest therapy taking rootResearchers find that a simple stroll among trees has real benefits
By AKEMI NAKAMURAStaff writer
For stressed-out workers this may someday be a doctors prescription Walk around in the woods
httpsearchjapantimescojpcgi-binnn20080502f1html
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
An interview from Bloomberg TVJuly 1 2009
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
The New York TimesReported our research on forest medicine on July 5 2010
Environ Health Prev Med 20101527-37
Environ Health Prev Med 20101518-26
Int J Immunopathol Pharmacol 2007203-8
J Biol Regul Homeost Agents 20082245-55
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
ReallyThe Claim Exposure to Plants and Parks Can Boost Immunity
This time of year allergies and the promise of air-conditioning tend to drive people indoors
But for those who can take the heat and cope with the pollen spending more time in nature might have some surprising health benefits In a series of studies scientists found that when people swap their concrete confines for a few hours in more natural surroundings mdash forests parks and other places with plenty of trees mdash they experience increased immune function
Stress reduction is one factor But scientists also chalk it up to phytoncides the airborne chemicals that plants emit to protect them from rotting and insects and which also seem to benefit humans
One study published in January included data on 280 healthy people in Japan where visiting nature parks for therapeutic effect has become a popular practice called ldquoShinrin-yokurdquo or ldquoforest bathingrdquo On one day some people were instructed to walk through a forest or wooded area for a few hours while others walked through a city area On the second day they traded places The scientists found that being among plants produced ldquolower concentrations of cortisol lower pulse rate and lower blood pressurerdquo among other things
A number of other studies have shown that visiting parks and forests seems to raise levels of white blood cells including one in 2007 in which men who took two-hour walks in a forest over two days had a 50-percent spike in levels of natural killer cells And another found an increase in white blood cells that lasted a week in women exposed to phytoncides in forest air
THE BOTTOM LINE
According to studies exposure to plants and trees seems to benefit health
ANAHAD OrsquoCONNOR scitimesnytimescom
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
Int J Immunopathol Pharmacol 200720(2)3-8Forest bathing enhances human natural killer activity and
expression of anti-cancer proteinsLi Q Morimoto K Nakadai A Inagaki H Katsumata M Shimizu T Hirata Y Hirata K Suzuki H
Miyazaki Y Kagawa T Koyama Y Ohira T Takayama N Krensky AM Kawada T
Department of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
In order to explore the effect of forest bathing on human immune function we investigated natural killer (NK) activity the number of NK cells and perforin granzymes and granulysin-expression in peripheral blood lymphocytes (PBL) during a visit to forest fields Twelve healthy male subjects age 37-55 years were selected with informed consent from three large companies in Tokyo Japan The subjects experienced a three-daytwo-night trip in three different forest fields On the first day subjects walked for two hours in the afternoon in a forest field and on the second day they walked for two hours in the morning and afternoon respectively in two different forest fields Blood was sampled on the second and third days and NK activity proportions of NK T cells granulysin perforin and granzymes AB-expressing cells in PBL were measured Similar measurements were made before the trip on a normal working day as the control Almost all of the subjects (1112) showed higher NK activity after the trip (about 50 percent increased) compared with before There are significant differences both before and after the trip and between days 1 and 2 in NK activity The forest bathing trip also significantly increased the numbers of NK perforin granulysin and granzymes AB-expressing cells Taken together these findings indicate that a forest bathing trip can increase NK activity and that this effect at least partially mediated by increasing the number of NK cells and by the induction of intracellular anti-cancer proteins
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
J Biol Regul Homeost Agents 200822(1)45-55A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects
Li Q Morimoto K Kobayashi M Inagaki H Katsumata M Hirata Y Hirata K Shimizu T Li YJ Wakayama Y Kawada T Ohira T Takayama N Kagawa T Miyazaki YDepartment of Hygiene and Public Health Nippon Medical School Tokyo Japan
Abstract
We previously reported that forest bathing trips enhanced human NK activity number of NK cells and intracellular anti-cancer proteins in lymphocytes and that the increased NK activity lasted for more than 7 days after the trip in male subjects In the present study we investigated the effect of forest bathing trip on human NK activity in female subjects Thirteen healthy nurses age 25-43 years professional career 4-18 years were selected with informed consent The subjects experienced a three-daytwo-night trip to forest fields On day 1 the subjects walked for two hours in the afternoon in a forest field on day 2 they walked for two hours each in the morning and afternoon in two different forest fields and on day 3 the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire Blood and urine were sampled on the second and third days during the trip and on days 7 and 30 after the trip NK activity numbers of NK and T cells and granulysin perforin and granzymes AB-expressing lymphocytes in the blood samples the concentrations of estradiol and progesterone in serum and the concentrations of adrenaline and noradrenaline in urine were measured Similar control measurements were made before the trip on a normal working day The concentrations of phytoncides in the forests were measured The forest bathing trip significantly increased NK activity and the numbers of NK perforin granulysin and granzymes AB-expressing cells and significantly decreased the percentage of T cells and the concentrations of adrenaline and noradrenaline in urine The increased NK activity lasted for more than 7 days after the trip Phytoncides such as alpha-pinene and beta-pinene were detected in forest air These findings indicate that a forest bathing trip also increased NK activity number of NK cells and levels of intracellular anti-cancer proteins in female subjects and that this effect lasted at least 7 days after the trip Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]
References1 Li Q et al Phytoncides (wood essential oils) induce human natural killer cell activity
Immunopharmacol Immunotoxicol 28 (2) 319-33 2006
2 Li Q et al Forest bathing enhances human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 20 (S2) 3-8 2007
3 Li Q et al Visiting a forest but not a city increases human natural killer activity and expression of anti-cancer proteins Int J Immunopathol Pharmacol 200821(1)117-27
4 Li Q et al A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects J Biol Regul Homeost Agents 200822(1)45-55
5 Li Q et al Relationships between percentage of forest coverage and standardized mortality ratios (SMR) of cancers in all prefectures in Japan The Open Public Health Journal 2008 1 1-7
6 Li Q et al Effect of phytoncide from trees on human natural killer function Int J Immunopathol Pharmacol 200922(4)951-9
7 Li Q Effect of forest bathing trips on human immune function Environ Health Prev Med 201015(1)9-17
8 Li Q et al A day trip to a forest park increases human natural killer activity and the expression of anti-cancer proteins in male subjects J Biol Regul Homeost Agents 201024(2)157-65
9 Li Q and Kawada T Effect of forest environments on human natural killer (NK) activity Int J Immunopathol Pharmacol 2011 24 (S1) 39-44
10 Li Q et al Acute effects of walking in forest environments on cardiovascular and metabolic parameters Eur J Appl Physiol 2011 Mar 23 [Epub ahead of print]