is ginseng an ergogenic aid? - human kinetics several species of ginseng are known to exist:...

Is Ginseng an Ergogenic Aid?

Michael S. Bahrke, Ph.D.(1), William P. Morgan, Ed.D.(2), and Aaron Stegner, Ph.D.(2) (1) Human Kinetics, Champaign, Illinois, USA 61825-5076 (2) Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, USA 53706 Address Correspondence to: Michael S. Bahrke, Ph.D. 12647 Door Bluff Rd. Ellison Bay, Wisconsin 54210 USA (V & F) 920.854.6265 [email protected]

of 44 International Journal of Sport Nutrition and Exercise Metabolism Â© Human Kinetics, Inc.

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Abstract Ginseng is one of the most popular herbal supplements in the world. While it is used for the treatment and prevention of many ailments, it is also used to increase work efficiency and is purported to increase energy and physical stamina. Athletes use ginseng for its alleged performance-enhancing attributes. However, many studies examining the pharmacological effects of ginseng on physical performance frequently have not employed sound scientific design and methodology. The purpose of this review is to provide an update of empirical research published focusing primarily on the efficacy of ginseng with respect to physical and athletic performance. Despite attempts in recent investigations to improve upon the scientific rigor used in examining the ergogenic properties of ginseng, we conclude that many of the same methodological shortcomings observed in earlier studies persist. Enhanced physical performance following ginseng administration in well-designed investigations remains to be demonstrated. Key Words: herbal supplement, pharmacological effects, performance-enhancement, athletic performance

of 44International Journal of Sport Nutrition and Exercise Metabolism Â© Human Kinetics, Inc.

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The world herbal supplements and remedies market is increasing at a phenomenal rate

(PRWeb Press Release Newswire, 2008). The top-selling herbal products in the United

States include echinacea, saw palmetto, ginkgo biloba, ginseng, and St. John’s wort,

among others (Healing Herbs and Natural Remedies, 2008). In a national survey

examining the prevalence of herbal supplement use in a sample of adults residing in the

U.S., nearly one in five surveyed consumed herbs during the past year (Bardia, Nisly,

Zimmerman, Gryzlak, & Wallace, 2007). Additional survey results collected from

collegiate (Froiland, Koszewski, Hingst, & Kopecky, 2004) and elite athletes, both in the

U.S. and abroad (Petroczi & Naughton, 2008; Slater, Tan, & Teh, 2003; Sundgot-Borgen,

Berglund, & Torstveit, 2003; Ziegler, Nelson, & Jonnalagadda, 2003) indicate ginseng is

one of the most popular herbal supplements consumed by athletes.

Ginseng is used worldwide for the treatment and prevention of many ailments, but

it has also been administered to increase occupational efficiency involving physical labor

and is purported to provide energy and increase physical stamina. Athletes use ginseng

for its alleged performance-enhancing attributes (Froiland, Koszewski, Hingst, &

Kopecky, 2004; Petroczi & Naughton, 2008; Slater, Tan, & Teh, 2003; Sundgot-Borgen,

Berglund, & Torstveit, 2003; Ziegler, Nelson, & Jonnalagadda, 2003). However, the

efficacy of ginseng has been inferred primarily through anecdotes, testimonials, clinical

experience, and animal research, as opposed to scientific verification of its

pharmacological effects on humans engaged in the type of physical performance pursued

by athletes.

The purpose of the current review is to provide an update of empirical research

published since our two earlier reviews (Bahrke & Morgan, 1994; Bahrke & Morgan,


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2000). There have been other reviews published since our most recent review, but with a

single exception (Pailisin & Stacy, 2006), these reviews have not focused on physical or

athletic performance (Attle, Wu, & Yuan, 1999; Lieberman, 2001). Furthermore, these

related reviews have not included the many varieties of ginseng (Davydov & Krikorian,

2000; Goulet & Dionne, 2006), nor have extensive and detailed summaries been provided

(Vogler, Pittler, & Ernst, 1999). We focus primarily on the efficacy of ginseng with

respect to physical and athletic performance in the current review. Specifically, in this

paper we provide an update on: (i) the physiological effects of ginseng and ginseng-

related products on physical activity, stress, and fatigue, (ii) the psychological,

behavioral, and cognitive effects, (iii) quality, purity, and bioavailability of ginseng

products, and (iv) the potential adverse health effects, drug interactions, and safety of

ginseng.

Varieties of Ginseng

Ginseng root is processed and distributed in various forms, including powder, liquid

extracts, tablets, capsules, and chewing gum. Roots are graded (sorted) according to their

source, age, part of the root, and method of preparation. The chemical composition of

commercial ginseng products is variable because of: (i) the genetic nature of the plant

source, (ii) the cultivation methods, and (iii) the drying and curing process (Hong, Lau,

Yeo, Liu, Yang, Kob, & Hong, 2005; Hu, 1976; Lim, Mudge, & Vermeylen, 2005). In

addition, some manufacturers add various substances (e.g., minerals and vitamins) to

ginseng products and there have been reports of drugs and alcohol being present in

ginseng products (USA Today, 1997).


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Several species of ginseng are known to exist: American, Chinese, Korean,

Japanese, and Siberian (Barna, 1985). Three medicinal species of ginseng are currently

recognized: Panax ginseng C.A. Meyer (Chinese or Korean ginseng, a perennial herb

indigenous to the mountainous forests of Eastern Asia); Panax japonicus C.A. Meyer

(Japanese ginseng, from India, Southern China, and Japan); and Panax quinquefolius

(American ginseng, found growing in rich woodland in the eastern and central U.S. and

Canada) (Court, 1975; Popov & Goldwag, 1973; Williams, 1957).

A preparation of Korean ginseng containing a standardized concentration of

ginsenosides has been used in a number of clinical and pharmacological studies. This

preparation, known as G115 (G115 is the registered trademark of a ginseng extract

containing all ginsenosides from the Korean Panax ginseng, GPL Ginsana Products SA,

Lugano, Switzerland) and marketed under the name of Ginsana, is widely used for the

treatment of a variety of problems such as reduced performance associated with general

fatigue states. Since these preparations sometimes contain other substances (e.g., alcohol,

vitamins, minerals) (Pietta, Mauri, & Rava, 1986), it is difficult to conclude that ginseng

per se possesses efficacy.

Siberian or Russian ginseng, although reported to have the same stimulant and

tonic effects as the other ginseng products, is an entirely different plant, Eleutherococcus

senticosus (Baranov, 1982; Brekman, 1965). The terms ciwujia, devil’s bush, wild

pepper, and shigoka are often used as synonyms for Siberian ginseng.

Eleutherococcus senticosus has been used as an inexpensive substitute for the

ginseng roots of Panax ginseng C.A. Meyer (Araliaceae) in republics of the former

Soviet Union and other countries. In reviewing the medicinal uses of ginseng and related


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plants in the Soviet Union, Baranov (1982) concluded that: (i) administration of E.

senticosus (eleuthero), unlike ginseng, never produces excitation in patients; (ii) the

effect of eleuthero on the general immunity of an organism is more universal than that of

ginseng; (iii) ginseng has anti-stress effects but, under certain conditions, may produce a

stress-like syndrome (eleuthero has no such effect); and (iv) the effect of both ginseng

and eleuthero varies seasonally, but this is less so for eleuthero.

Like Siberian or Russian ginseng, Panax japonicus C.A. Meyer has been used in

Japan as a substitute for Panax ginseng C.A. Meyer in the treatment of gastroenteric

disorder and as an antitussive, expectorant and antipyretic. American ginseng (Panax

quiquefolius) is sold worldwide in forms such as processed roots, powders, teas, and

capsules. It is used as an analeptic, tonic, stomach pain analgesic, and adaptogenic agent

(any substance that exerts effects on both sick and healthy individuals by “correcting”

any dysfunction(s) without producing unwanted side effects (Davydov & Krikorian,

2000)). It has also been widely promoted as an aphrodisiac (Liberti & Der Marderosian,

1978).

The main active constituents of the Panax species are recognized to be

triterpenoid glycosides or saponins and are termed ginsenosides by Chinese, Korean, and

Japanese researchers, while the active components of Eleutherococcus senticosus are

termed panaxosides by Russian workers, whose structures and distribution vary with

species and variety. Identification of the active elements, the establishment of reliable

techniques for the isolation and standardization of the active components, and the

extensive evaluation of the active components and pharmacological properties has

occurred during the past few decades (Hou, 1977; Iwabuchi, Yoshikura, Ikawa, &


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Kamisako, 1987; Iwabuchi, Yoshikura, & Kamisako, 1988; Kasai, Yamaguchi, &

Tanaka, 1987). Chromatographic methods are now available for the identification of

saponins that make ginseng detection and differentiation relatively simple (Liberti & Der

Marderosian, 1978; Phillipson & Anderson, 1984; Pietta, Mauri, & Rava, 1986; Shibata,

Fujita, Itokawa, Tanaka, & Ishii, 1963; Tanaka, Nagai, & Shibata, 1966; Yamaguchi,

Kasai, Matsuura, Tanaka, & Fuwa, 1988). Ginseng saponins have been investigated (Iida,

Tanaka, & Shibata, 1968; Tanaka, Nagai, & Shibata, 1966; Wenkui, Chungang, Zhang,

Awang, Fitzloff, Fong, & van Breeman, 2000), and at least 31 saponins have been

isolated from extracts of Panax ginseng roots (Court, 1975; Hou, 1977). The major

saponins have been named ginsenosides Rx, where x is a, b1, b2, c, d, e, f, g1, g2, g3, h1,

h2, or o, according to their position on thin layer chromatograms (Shibata, Tanaka, Soma,

Iida, Ando, & Nakamura, 1965).

Among the various types of ginseng, Korean ginseng appears to be relatively rich

in ginsenosides. In Korean Panax ginseng, ginsenosides Rb1, Rc, and Rg1 are major

saponins, and although American P. quinquefolius is similar in its constituents there are

significant differences (Besso, Kasai, Wei, Wang, Saruwatari, Fuwa, & Tanaka, 1982;

Phillipson & Anderson, 1984). The most significant difference between American and

Korean ginsengs is that American ginseng is believed to have cooling and energizing

effects on the body, whereas Korean ginseng is thought to have warming and calming

effects on the body. The roots of Japanese ginseng, Panax japonicus, contain mainly

different saponins, which are known as chikusetsu-saponins. Only two saponin

glycosides are common to Japanese, Chinese, Korean, and American ginseng, namely

Rg2, and Ro (Russian panaxosides do not correspond with those of the ginsenosides).


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The active constituents of Russian ginseng (E. senticosus) are a series of

eleutherosides coded A to F (Elyakov, Strigina, Uvarova, Vaskovasky, Dzizenko, &

Kochetkov, 1964). The major eleutherosides are completely different in chemical

structure from the ginsenosides. The resultant variety of saponins which can co-occur,

each with its own pharmacological activity, is probably responsible for the lack of

consensus among researchers on the pharmacology of ginseng. In fact, in the U.S., the

2002 Farm Security & Rural Investment Act (United States Department of Agriculture,

2002) states that “the term ‘ginseng’ may only be considered to be a common or usual

name (or part thereof) for any herb or herbal ingredient derived from a plant classified

within the genus Panax and only labeling or advertising for herbs or herbal ingredients

classified within that genus may include the term ‘ginseng’”.

Ginseng grows wild, is also cultivated, and is generally harvested after growing

six to seven years. Although the entire ginseng plant contains pharmacologically active

properties (Petkov, Yinglin, Todorov, Lazarova, Getova, Stancheva, & Alova, 1992), it is

the root of the plant that is considered most valuable. In fact, over $81,000 has been paid

for a small, 124-year-old ginseng root (CNN.com/WORLD, 2001). Extracts of red and

white ginseng contain different ginsenosides (Chong & Oberholzer, 1988). White ginseng

is produced by air-drying the root, while red ginseng is produced by steaming the root

followed by drying. Red ginseng has been used for treatment of weak constitution, ulcers,

cold symptoms or anemia, and as an analeptic, a stomachic, and as an erythropoietic

within the traditional Chinese system of medicine (Matsuda, Namba, Fukuda, Tani, &

Kubo, 1986). The latter, i.e., erythropoiesis, is potentially relevant for application with

athletes engaged in endurance events. The ginsenoside content of dried ginseng root may


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vary with root age, method of preservation, and season of harvest (Liberti & Der

Marderosian, 1978). High quality ginseng should be collected in the autumn and never

before five to six years of growth (Popov & Goldwag, 1973). For example, while most

roots present at least four detectable ginsenosides, after six years of growth roots show

more extensive patterns and may yield up to nine ginsenosides (Liberti & Der

Marderosian, 1978).

Physiological Effects

Previous reviews have documented the physiological effects of ginseng (Bahrke &

Morgan, 1994; Bahrke & Morgan, 2000). Studies dealing with the cardiovascular effects

of ginseng, have reported that various preparations and concentrations can reduce,

elevate, or stabilize blood pressure, and influence platelet aggregation. It appears that

ginsenosides can have hypertensive as well as hypotensive effects. However, these

effects are transient, relatively minor, and dose dependent. Research published since our

last review also indicates that ginseng may improve cardiovascular and pulmonary

function, and this could enhance physical performance.

In a randomized, double-blind, placebo-controlled trial, Stavro, Woo, Heim,

Leiter, and Vukan (2005) investigated the effect of six batches of North American

ginseng root that varied in quality and ginsenoside content on blood pressure in 16

hypertensive individuals, but not performance in healthy athletes. None of the North

American ginsengs or their mean differed from placebo in their effect on overall mean

blood pressure change suggesting that North American ginseng has no effect on blood

pressure in hypertensive individuals.


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The effects of ginseng on pulmonary function and exercise capacity have been

reported in earlier studies. However, many of these investigations have been conducted

with patients suffering from compromised pulmonary function and low levels of exercise

capacity. In an investigation designed to evaluate the effects of ginseng extract (G115) on

pulmonary function and exercise capacity, Gross, Shenkman, Bleiberg, Dayan, Gittleson,

and Efrat (2002) assigned 94 patients with moderately-severe chronic obstructive

pulmonary disease to either an experimental group that received 100 mg of G115, twice

daily, or a control group that received a placebo over a 3-month study period. Pulmonary

function tests: maximum voluntary ventilation and maximum inspiratory pressure were

administered prior to treatment and every two weeks during the 3-month period. Exercise

tests and VO2max measurements were performed before beginning treatment, at 6 weeks,

and after 3 months. In the experimental treatment, but not the placebo treatment, all

parameters significantly increased above baseline and surpassed those changes noted for

the placebo group. Maximum voluntary ventilation increased 40%, maximum inspiratory

pressure improved 47%, and maximal oxygen consumption increased 38%. No side

effects were observed. It appears ginseng may have its most significant effects in

individuals with compromised respiratory systems, but this cannot be taken to assume it

would have an effect on healthy athletes.

Effects on Physical Activity, Stress, and Fatigue

Ginseng and ginseng-related products have been used for years as an energy booster and

as a general tonic. Some reports suggest ginseng may enhance antibody production and

natural killer cell activity and play a role in the prevention and therapy of respiratory

disorders (Choi, 2008). There is evidence that intense physical training can produce


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temporary changes in the endocrine and immune systems and one of the reasons athletes

use Panax ginseng or Eleutherococcus senticosus is the belief that these herbs decrease

the incidence of colds and infections and enhance recovery from intense training.

Stress and Immune System. Gaffney, Hugel, and Rich (2001a), using a 6-week, double-

blind, placebo-controlled study examined the ability of Panax ginseng (type not

specified) and Eleutherococcus senticosus to influence measures of stress and selected

parameters of immune system status in competitive club-level, male athletes engaged in

normal training during the competitive season. Thirty participants were matched for

training stress and received a 33% ethanolic extract containing either a Panax ginseng

treatment, an Eleutherococcus senticosus treatment, or a placebo treatment. A pre-test

and post-test were used to evaluate the effects of 6 weeks of supplementation on cortisol,

testosterone, and testosterone to cortisol ratio as well as circulating numbers of T-cells,

T-helper cells (CD4), T-suppressor cells (CD8), CD4 to CD8 ratio, natural killer cells,

and B lymphocytes. None of the immune system variables changed significantly nor

showed any clear trend from pre- to post test in any of the treatment groups. No

significant change in testosterone, cortisol, or total testosterone to cortisol ratio (TCR)

was observed in the Panax ginseng treatment group. However, in the Eleutherococcus

senticosus treatment group, TCR significantly decreased by 28.7%. The main

contribution to this decrease appeared to be a non-significant trend towards increased

cortisol rather than a small decrease in mean testosterone levels. These results suggest

that Eleutherococcus senticosus increased rather than decreased hormonal indices of

stress. There is animal research suggesting a threshold of stress below which

Eleutherococcus senticosus increases the stress response and above which


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Eleutherococcus senticosus decreases the stress response (Gaffney, Hugel, & Rich,

2001a).

Gaffney, Hugel, and Rich (2001b) have proposed a mechanism of action for

Panax ginseng and Eleutherococcus senticosus that attempts to explain why these herbs

produce the paradoxical effect of sometimes increasing and sometimes decreasing the

stress response. The mechanism suggests this biphasic effect results from increased

occupancy of positive and negative feedback stress hormone receptors by their natural

ligands to inhibition of specific enzymes that function to limit receptor occupancy.

Specifically, Gaffney et al. (2001b) suggest that Panax ginseng inhibits 11-beta

hydroxysteroid dehydrogenase one and Eleutherococcus senticosus inhibits catechol-O-

methyl transferase, both of which reside in close proximity to stress hormone receptors

and catalyze the degradation of stress hormones into inactive compounds. In addition,

Gaffney et al. (2001b) suggest the increased energy claimed to result from Panax ginseng

and Eleutherococcus senticosus may be a consequence of their increasing the occupancy

of stress hormone receptors that function to redistribute the body’s energy reserves from

regeneration to activity.

In an investigation designed to examine the efficacy of ginseng to modulate

secretory immunoglobulin A, exercise performance, and recovery from repeated bouts of

strenuous physical exertion, Engels, Fahlman, and Wirth (2003) used a double-blind,

placebo-controlled, randomized design with 38 active healthy adults who supplemented

their diets with a standardized ginseng concentrate (400 mg G115) or placebo for 8

weeks. Prior to and following the treatments, each subject performed 3 consecutive 30-

second Wingate tests interspersed with 3-minute recovery periods. Secretory


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immunoglobulin A secretion rate (S-SIgA) and the relation of secretory immunoglobulin

A (SIgA) to total protein were calculated from measures of saliva flow rate (SFR) and

absolute SIgA and salivary protein concentrations samples were collected before and

after exercise testing. Peak and mean mechanical power output and exercise recovery

heart rate were also measured. Of the 38 subjects initially enrolled in this investigation,

11 failed to complete one or more basic study requirements and the final data analyses

were performed on measurements obtained from 27 subjects. Compared with rest, S-

SIgA, SIgA:protein ratio, and SFR were significantly lower after exercise at baseline.

Likewise, both peak and mean mechanical power output significantly declined across

consecutive Wingate tests. Post intervention minus pre-intervention changes in scores for

salivary parameters, exercise performance, and exercise heart rate recovery were similar

between the treatment groups. These findings do not support the hypothesis that ginseng

may affect mucosal immunity as indicated by changes in secretory IgA at rest and

following an exercise-induced state of homeostatic disturbance. Supplementation with

ginseng failed to improve physical performance and heart rate recovery of individuals

undergoing repeated bouts of exhaustive exercise.

Strength/Power Performance. In an investigation by Kang, Kim, Lee, and Byrne

(2002), designed to assess the anabolic effects of ginseng ingestion on growth hormone,

testosterone, cortisol, and insulin-like growth factor-1 to acute resistance exercise, 8 male

college students were randomly administered 20 g of Korean red ginseng root extract or

water immediately following a standardized exercise bout. The exercise consisted of a 7-

repetition maximum of the half squat, bench press, 2-leg curl, arm curl, 2-leg extension,

abdominal crunch, leg press, and chest press. Venous blood samples were drawn prior to


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and immediately following exercise and at again at 15-, 30-, 60-, and 120-minutes

following exercise. Human growth hormone, testosterone, cortisol, and insulin-like

growth factor-1 levels were determined by radioimmunoassay. The responses of plasma

hormones did not differ significantly following the treatments. These results do not

support the use of ginseng to promote anabolic hormonal status following resistance

exercise.

Aerobic Exercise Performance. To evaluate the effectiveness of 14 days of treatment

with Eleutherococcus senticosus (ES) (900 mg/day) as an ergogenic nutritional

supplement, Chase, Darby, Liang, and Morgan (2000) employed a double-blind,

crossover study with 11 participants performing four running trials before and following

treadmill running performed at 80% of VO2 max until volitional exhaustion following ES

and placebo treatments. There was no statistically significant difference between trials for

any of the dependent variables including time to exhaustion. The investigators concluded

that 14 days of supplementation with Eleutherococcus senticosus has no ergogenic effect

on metabolism and performance.

To determine if Panax quinquefolium attenuates creatine kinase level induced by

aerobic endurance exercise in humans, Hsu, Ho, Lin, Su, and Hsu (2005) divided 13 male

college students into a ginseng or placebo group. In a double-blind study, subjects

received supplementation (400 mg, 4 per day) for 4 weeks, followed by a 4-week

washout period, before crossing over and receiving the alternate treatment for the next 4

weeks. Treadmill running at 80% of VO2 max was performed following each treatment.

Plasma creatine kinase and lactate were measured prior to the exercise, at 15 and 30

minutes during exercise, immediately after exercise, and 20, 40, 60, and 120 minutes


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after exercise. In addition, time to exhaustion and oxygen pulse were also measured.

While ginseng supplementation for 4 weeks prior to exhaustive aerobic treadmill running

was associated with reduced leakage of creatine kinase from skeletal sarcoplasm into the

blood during exercise, it did not enhance performance.

It has been reported by Kim, Park, Chang, and Sung (2005) that administration of

Panax ginseng increases endurance time to exhaustion. In this study, 7 sedentary males

performed incremental exercise to volitional exhaustion on a treadmill before and

following 8 weeks of panax ginseng extract administration. Exercise duration until

exhaustion was significantly increased by 1.5 minutes, leading the investigators to

conclude that ginseng has ergogenic properties. There are a number of reasons why these

findings and conclusions must be viewed with caution. First, a small sample size of seven

males served as participants, and these individuals served as their own controls. Second,

the control testing was carried out prior to the ginseng intervention, and it is possible that

an order effect took place. That is, the conditions should have been rotated and randomly

assigned to the participants (i.e., AB and BA). Third, the participants were recruited on

the basis that they “…had not performed any systematic training,” and this is problematic

for two reasons. First, pre-test sensitization may have taken place and second, the results

cannot be generalized to athletes. Fourth, there was no blinding, and therefore, the

observed results may have been due to the Halo effect, Hawthorne effect, demand

characteristics, or expectancy effects.

In a double-blind, placebo-controlled investigation to determine the effectiveness

of a moderately high dose of Panax notoginseng (a species of the genus Panax) on

aerobic capacity, endurance, and mean blood pressure in young adults, Liang, Podolka,


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and Chuang (2005) randomly assigned 29 untrained adults to an experimental group or

placebo control group. For 30 days, subjects in the experimental group consumed 1,350

mg per day of Panax notoginseng, while subjects in the control group consumed a

placebo. Endurance time to exhaustion during cycle exercise was significantly improved

in the experimental group by more than 7 minutes and mean blood pressure and oxygen

consumption decreased during endurance exercise. The significant improvement in

endurance time demonstrated by this investigation compared with others is noteworthy

for several reasons: a relatively high dose of assayed ginseng was used, duration of

consumption was for 30 days, and the type of ginseng consumed was Panax notoginseng,

as opposed to the more frequently used Panax ginseng. In addition, the experimental

design was comparatively rigorous being double-blind with random assignment of a

moderate number of subjects to either a treatment or a placebo group. The investigators

report that subjects were randomly assigned to the placebo and ginseng treatments, but

there was a substantial difference in maximal oxygen consumption at the outset of the

study. The entire point of using randomization is to insure that experimental and placebo

groups are equivalent from the outset of a study on all variables of relevance to the

inquiry. The effect size for the difference in maximal oxygen uptake was large (.81), and

this is problematic. In other words, the ginseng group, for some reason, was superior to

the placebo group from the outset on an important dimension of physical fitness.

Anaerobic Exercise Performance. To investigate the effects of ginseng supplementation

on supramaximal exercise performance and short-term recovery, Engels, Kolokouri,

Cieslak, and Wirth (2001) used a double-blind protocol and randomly assigned 24

healthy, active women to either a ginseng or a placebo treatment. Each participant added


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a standardized extract (400 mg G115) of Panax ginseng C.A. Meyer or a placebo to their

normal diet for 8 weeks. Prior to and following the treatment period, each subject

performed an all-out-effort, 30-second leg cycle ergometry test followed by a controlled

recovery. Nineteen subjects completed the study. Of the 5 subjects lost to follow-up, 3

were from the placebo group and 2 were from the ginseng group. Results revealed no

significant differences between the ginseng and placebo treatment groups for peak

anaerobic power output, mean anaerobic power output, rate of fatigue, and immediate

post exercise recovery heart rates. Engels et al. (2001) concluded that prolonged

supplementation with ginseng had no ergogenic benefits during and following brief,

supramaximal exercise. Effect sizes for the ginseng treatment were small (peak anaerobic

power, 0.00; mean anaerobic power, 0.06; rate of fatigue, 0.38).

To determine the effects of ginseng supplementation on lactate threshold and

physical performance, Kulaputana, Thanakomsirichot, and Anomasiri (2007) randomly

assigned 57 physically active young men to either a ginseng (n = 28) or a placebo group

(n = 29). Participants in the ginseng group consumed 3 gm of ginseng orally each day for

8 weeks. Blood lactic acid levels and heart rate responses were measured during

incremental cycle ergometer work before and after the 8 weeks of treatment. Selected

markers for liver and renal function were also monitored. Lactate threshold, exercise

heart rate, total exercise time, and peak power output did not differ between ginseng and

placebo groups, demonstrating in a well-controlled study (randomized, double-blinded,

placebo-controlled, treatment compliance monitoring) that ginseng supplementation did

not exert an ergogenic effect on the physical performance of a relatively large group of

physically active young men.


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The reports described in this section are summarized in Table 1.

In conclusion, additional, well-designed research is needed to determine whether

supplementation with ginseng and related products can improve performance and

alleviate stress and fatigue when functional abilities are diminished such as through

repetitive bouts of strenuous physical work. Moreover, the potential use of ginseng and

related products to enhance performance, recovery, and muscle growth from anaerobic

exercise has not yet been adequately investigated.

Psychological, Behavioral, and Cognitive Effects

While the positive effects of ginseng and ginseng-related products on psychological

function, moods, behavior, stress reduction, and chronic pain in humans have been

reported in a few of the earlier studies in this area – perhaps resulting from several central

and peripheral physiological effects including cardiovascular, neural, and hormonal

(Bahrke & Morgan, 1994; Bahrke & Morgan, 2000), a more recent research study has

failed to demonstrate enhanced mood following ginseng administration in healthy young

adults.

Using a double-blind, placebo-controlled, randomized clinical trial, Cardinal and

Engels (2001) examined the psychological well-being in healthy, young adults. Ninety-

six adults were randomly assigned to one of three experimental conditions: placebo, 200

mg ginseng (Panax ginseng C.A. Meyer concentrate G115 in capsular format), or 400 mg

ginseng (Panax ginseng C.A. Meyer concentrate G115 in capsular format). Each

participant was given a 60-day supply of their respective supplement along with written

instructions about proper intake and storage of the capsules over the 8-week study period

and, a post-intervention appointment was scheduled for each participant. Eighty-three (or


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86.5%) of the original participants completed the study with the primary reason for

attrition being noncompliance with the study protocol. Positive affect, negative affect,

and overall mood measures were obtained pre- and post-intervention. Ginseng

supplementation had no effect on positive affect, negative affect, or overall mood leading

the researchers to conclude chronic ginseng supplementation at either the clinically

recommended dose, or at twice that level, does not enhance mood in healthy young

adults. However, it may be that ginseng has little or no effect when administered to

healthy adults scoring in the normal range on mood states. The investigators did not

examine the effects of ginseng in those study participants with elevated mood scores.

In sports where quick decision-making is required, it is not unusual for athletes to

consume products thought to provide an advantage over the competition. However, while

previous research suggests chronic administration of ginseng can improve cognitive

performance in humans (Bahrke & Morgan, 1994; Bahrke & Morgan, 2000), previous

research has not examined the effects of a single dose of ginseng on cognitive

performance in healthy adults or with athletes.

In an investigation to determine if the acute administration of ginseng (G115) had

any consistent effect on mood and cognitive performance in humans, Kennedy, Scholey,

and Wesnes (2001a) used a placebo-controlled, double-blind, balanced, cross-over

design. Quality of memory, speed of memory, quality of attention, and speed of attention

served as the cognitive measures. Twenty, healthy young adult volunteers received 200,

400, and 600 mg of G115, and a matching placebo, in counterbalanced order, with a 7-

day washout period between treatments. Following a baseline cognitive assessment,

further test sessions took place at 1, 2.5, 4, and 6 hours after the day’s treatment.


20

Significant improvement was found for quality of memory and the associated factor

known as “secondary memory” at all points following the administration of 400 mg of

ginseng. Both the 200 and 600 mg doses were associated with a significant decrement of

the speed of attention at later testing times only. Subjective ratings of alertness were also

reduced six hours following the two lowest doses (200 mg and 400 mg). These results

indicate modulation of mood and cognitive performance may occur following acute

administration of ginseng, but there is not a linear dose-response effect. That is, a

moderate dose of 400 mg seems to enhance performance, while low (200 mg) and high

(600 mg) doses impair performance. It would be noteworthy, of course, if similar results

were found in exercise and sport settings.

In a subsequent investigation, but with different dosages, Kennedy, Scholey, and

Wesnes (2001b) examined the effects of a combination of standardized extracts of

Ginkgo biloba (GK501) and Panax ginseng (G115) on mood and selected aspects of

cognitive performance (Quality of Memory, Speed of Memory, Quality of Attention, and

Speed of Attention). Using a placebo-controlled, double-blind, balanced, cross-over

design, 20 healthy, young adult volunteers received 320, 640, and 960 mg of the extract

combination and a matching placebo in a random order with a 7-day washout period

between treatments. Following a baseline cognitive assessment, further testing took place

at 1, 2.5, 4, and 6 hours after the day’s treatment. There was a dose-response

improvement in performance on the quality of memory factor at the highest dose (960

mg). Additional analysis indicated this effect was differentially targeted at the secondary

memory rather than the working memory component. There was also a dose-response

decrement in performance of the speed of attention factor for both the 320 and 640 mg


21

doses. The results of this study suggest that ingestion of single doses of a Ginkgo biloba

and Panax ginseng combination can affect the cognitive performance of healthy young

volunteers in a dose-response manner in that low doses are associated with performance

decrements while high doses enhance performance. The underlying mechanism(s) for

these effects remain to be elucidated.

In a related investigation, Kennedy, Scholey, and Wesnes (2002) directly

compared the effects of single doses of Ginkgo biloba, ginseng, and a gingko/ginseng

combination on aspects of mood and cognitive performance using subjects from the same

cohort of healthy, young adult volunteers. Using a randomized, placebo-controlled,

double-blind, balanced, cross-over design, 20 participants received what investigators

referred to as “the most beneficial dose” from each of their previous Cognitive Drug

Research battery-based studies: 360 mg of Ginkgo biloba, 400 mg of ginseng, 960 mg of

a product combining the two extracts with an inert substance, and a matching placebo.

Treatment was random and there was a 7-day washout period between treatments.

Cognitive testing involved use of the Cognitive Drug Research Battery and two serial

subtraction mental arithmetic tasks. Mood was assessed with the Bond-Lader visual

analogue scales. Following a baseline cognitive assessment, further testing took place at

1, 2.5, 4, and 6 hours after the day’s treatment was taken. All three treatments were

associated with improved secondary memory performance as measured by the Cognitive

Drug Research Battery, with the ginseng condition resulting in some improvement in the

speed of performing memory tasks and in the accuracy of attentional tasks. Following

ginkgo and the ginkgo/ginseng combination, performance of both subtraction tasks was

improved at the later testing sessions. No change in the speed of performing attention


22

tasks was found. Improvement in self-rated mood was also found following ginkgo and to

a lesser extent, the combination product. These results suggest that ingestion of single

doses of Ginkgo biloba, Panax ginseng, and a product combining the two extracts can

beneficially influence the cognitive performance of healthy, young volunteers. While

findings of this nature are often advanced as evidence for the efficacy of ginseng and

related substances in the enhancement of performance in athletes, there is an absence of

compelling research evidence to support such views. This research lacks what is known

as external validity and it would be a fundamental scientific error to make such

generalizations.

The electroencephalographic (EEG) effects of single doses of Ginkgo biloba and

Panax ginseng in healthy young volunteers have also been examined by Kennedy,

Scholey, Drewery, Marsh, Moore, and Ashton (2003). Using a double-blind, placebo-

controlled, balanced crossover experiment, the effects of single doses of Ginkgo biloba

(360 mg GK501), Panax ginseng (200 mg G115), and an identical placebo on auditory-

evoked potential using contingent negative variation and resting power within the delta,

theta, alpha, and beta wavebands were evaluated in 15 healthy volunteers. Each subject

was assessed on three separate occasions, 4 hours after consuming the treatment of the

day. Seven days elapsed between testing sessions. Results indicated that ginseng led to a

significant shortening of the latency of the P300 component of the evoked potential. Both

ginseng and Ginkgo biloba led to significant reductions in frontal “eyes closed” theta and

beta activity, with additional reduction for ginseng in the alpha waveband. These findings

demonstrate that Panax ginseng can directly modulate cerebroelectrical activity, and that

these effects are more pronounced than those following Ginkgo biloba. This potential for


23

ginseng to enhance cognitive performance and mood has been reviewed in greater detail

by Kennedy and Scholey (2003) and Scholey and Kennedy (2002). It should also be

noted that EEG data cannot be used as evidence of activity in sub-cortical regions, and

there is a need for neuroimaging research (e.g., MRI, PET, SPECT) designed to elucidate

the impact of ginseng use on various brain regions.

In one of the few ginseng administration studies conducted with athletes,

improved psychomotor performance at rest and during graded exercise following ginseng

treatment (350 mg/day for 6 weeks) in young athletes has been demonstrated by Ziemba,

Chmura, Kaciuba-Uscilko, Nazar, Wisnik, and Gawronski (1999). In a double-blind

study, 15 soccer players underwent either ginseng treatment or placebo treatment. Prior to

and following treatment all subjects performed an incremental bicycle ergometer exercise

with intensity increasing 50 W every 3 minutes until volitional exhaustion (time to

exhaustion data not presented). Reaction time was measured before exercise and during

the last 2 minutes of each exercise load. Although neither ginseng nor placebo influenced

VO2 max or lactate threshold, ginseng treatment was associated with shortened reaction

times at rest and during exercise.

To elucidate the mechanism(s) for the gluco-regulatory properties and

enhancement of cognitive performance following ginseng administration, in a double-

blind, balanced-crossover study, Reay, Kennedy, and Scholey (2006) used a “cognitive

demand” test battery at baseline, 30 minutes following administration of either ginseng or

a placebo, and another 30 minutes later after consuming a drink containing glucose or a

placebo. Both ginseng and glucose were associated with enhanced cognitive

performance. Ginseng was associated with a reduction in blood glucose levels 1 hour


24

following consumption when ingested without glucose, confirming ginseng may lower

blood glucose levels and enhance cognitive performance. Although the mechanism(s)

responsible for ginseng’s glycemic effect or its cognitive effects were not clarified by this

investigation, possible mechanisms for lower blood glucose levels and improved

cognitive performance could include the modulation of glucose disposal, glucose

transport, or insulin secretion.

The reports described in this section are summarized in Table 2.

In conclusion, while current research supports the general finding that

supplementation with ginseng and related products may modulate mood, improve

cognitive performance, and decrease reaction time, the ecological validity of applying

such results, primarily obtained using non-athletes in laboratory settings, to athletes and

athletic environments is questionable.

Quality, Purity, and Bioavailability

Variability in herbal products, including ginseng, is a major concern as most dietary

supplements are not subject to the same regulations as pharmaceuticals, and these herbal

products may lack purity or potency. Hence, research involving herbal products is

associated with major “sourcing” problems, and it is imperative that investigators assay

the content of products employed in experiments designed to quantify efficacy. In our

view, it is noteworthy that nearly all of the investigations in the present review failed to

include an assay of the actual content of the substances used in the experiment.

To determine the variability in a range of ginseng herbal products available in the

U.S., Harkey, Henderson, Gershwin, Stern, and Hackman (2001) identified and measured

the concentration of marker compounds by using high performance liquid


25

chromatography (HPLC) and liquid chromatography-tandem mass spectrometry. Twenty-

five commercial ginseng preparations of Panax ginseng or Eleutherococcus senticosus

were obtained from a local health food store and analyzed for seven ginsenosides and two

eleutherosides. All plant species were correctly identified by botanical plant species, but

concentrations of marker compounds differed significantly from labeled amounts. There

was also significant product-to-product variability and concentrations of ginsenosides

varied by 15- and 36-fold in capsules and liquids respectively, and concentrations of

eleutherosides varied by 43- and 200-fold in capsules and liquids respectively. The

results of this survey suggest standardization for quality assurance is important in the

design and evaluation of ginseng studies.

In a study to determine whether the commercial formulations of several botanical

dietary supplements, including ginseng, had consistent labeling and whether quantities of

marker compounds agreed with the amounts on the label, Krochmal, Hardy, Bowerman,

Lu, Wang, Elashoff, and Heber (2004) purchased six bottles each of two lots of

supplements from nine manufacturers and analyzed the contents using established

commercial methodologies at an independent laboratory. Product labels were found to

vary in the information provided, such as serving recommendations and information

about the herb itself (e.g., species, part of the plant, marker compound). With regard to

marker compound content, little variability was observed between different lots of the

same brand, while the content did vary widely between brands (e.g., total ginsenosides

ranged from 5.3 to 18.2 mg per serving). Further, the amounts recommended for daily use

also differed between brands, increasing the potential range of a consumer’s daily dose.


26

Ginseng was among the most variable. This study emphasizes the importance of

standardized manufacturing practices and reliable labeling information.

Using HPLC to evaluate the effects of different samples of Panax quinquefolius

on specimens cultivated in Wisconsin and Illinois, Yuan, Wang, Wu, Attlele, Xie, and Gu

(2001) found considerable variability in the brainstem activity of neonatal rats for the two

samples. In a comparison of six ginsenosides from these two specimens, data revealed

remarkable variability in the total concentration and in the percentages of individual

ginsenosides. For example, of the two major ginsenosides, the Illinois-cultivated Panax

quinquefolius had 30% less ginsenoside Rb1 and 25% more ginsenoside Re than did the

Wisconsin-cultivated Panax quinquefolius.

As part of a program for assessment of the quality of herbal medicines, Khan,

Allgood, Walker, Abourashed, Schenk, and Benson (2001) analyzed 21 over-the-counter

Panax ginseng products in various dosage forms including 8 liquid samples and 13 solid

samples. Chromium, mercury, and arsenic were undetectable above their limits of

detection in both liquid and solid samples, but cadmium, lead, and nickel were present in

the majority of samples. Chlorinated pesticide levels varied widely in these samples. The

total concentration of pesticides was below 100 ppb in most samples, but the total

concentration exceeded 100 ppb in five samples. In addition, the U.S. Food and Drug

Administration recently issued a warning that certain ginseng products are considered

adulterated because they contain unsafe chemical residues from the pesticides

procymidone and quintozene (Anonymous, 2005). In another investigation examining the

concentrations of cadmium, lead, mercury, and metalloid arsenic in dietetic products,

Dragun, Puntaric, Prpic-Majic, Bosnir, Gmajnic, and Klaric (2003) found the highest


27

concentration of mercury in a ginseng-based sample. Raman, Patino, and Nair (2004)

failed to find unacceptable concentrations of metals such as lead and mercury in eight

botanical dietary supplements including ginseng. However, these supplements were also

evaluated for microbial contamination and most samples analyzed showed the presence

of bacteria or fungi or both. These results serve to identify the problem of environmental

contamination of dietary supplements and emphasize the necessity for developing

validated quantitative methods for the analysis of such contaminants in the various herbal

products presently available.

The above results also emphasize that future investigations of the effectiveness of

ginseng should rely on the use of standardized methods and preparations. In fact,

Sievenpiper, Arnason, Vidgen, Leiter, and Vuksan (2004), after conducting a systematic

quantitative analysis of the literature and finding a high coefficient of variation in

ginsenosides across species, assay technique, and ginsenoside type concluded “…that

until these issues are resolved, the reproducibility of ginseng’s composition, safety, and

efficacy cannot be trusted.”

In an attempt to authenticate the differences between various types of Panax

ginseng and, to offer confidence to consumers, Hon, Chow, Zeng, and Leung (2003)

developed a set of microsatellite markers with discrete genotypes for American ginseng

(Panax quinquefolius) that are able to differentiate Panax quinquefolius from Panax

ginseng with resolution down to specific, individual farm level; that is, confirmation of

its botanical identity and origin. Compared with other molecular techniques,

microsatellite marker technology is more robust, accurate, reproducible, reliable, and

sensitive. Also to ensure quality control and standardization of ginseng, Asafu-Adjaye


28

and Wong (2003), using liquid chromatography in an interlaboratory study involving 12

collaborating laboratories, reliably identified six common ginsenosides in dry root

powder from Panax ginseng, Panax quinquefolius, and two selected commercial ginseng

products. In response to the need to standardize the quality and purity of ginseng

products, the Korean Ministry of Agriculture and Forestry (Korea Herald, 2002), has

submitted a draft on the international food standard for ginseng to the Italian-based

executive office of the Codex Alimentarius Commission. This Commission was created

by the Food and Agriculture Organization and the World Health Organization to facilitate

standardization of food. The draft includes basic conditions, including the definition

range and structural elements of ginseng.

One of the factors in determining the ergogenic effects of ginseng is the systemic

availability and degradation of the constituent ginsenosides following oral administration

in humans. Using mass spectrometry, Tawab, Bahr, Karas, Wurglics, and Shibert-

Zsilavecz (2003) studied the degradation of ginsenosides in the gastrointestinal tract of

humans following the oral administration of ginseng. Plasma and urine samples from 2

human subjects were screened for ginsenosides and their possible degradation products. It

was shown that two hydrolysis products of the protopanaxatriol ginsenosides G-Rh and

G-F, may reach the systemic circulation. In addition, compound-K, the main intestinal

bacterial metabolite of the protopanaxadiol ginsenosides was detected in plasma and

urine. These substances or components are probably responsible for the action of ginseng

in humans.


29

Adverse Effects, Drug Interactions, and Safety

The adverse effects associated with ginseng consumption have been reported previously

(Bahrke & Morgan, 1994; Bahrke & Morgan, 2000). While ginseng is thought to be

relatively safe, several recent reports on the adverse effects of ginseng have been

published. A systematic attempt to document and evaluate all of the available data on the

safety of Panax ginseng root extracts has been conducted by Coon and Ernst (2002). Data

from clinical trials suggest the incidence of adverse events with ginseng

monopreparations is similar to that of placebo. The most commonly experienced adverse

effects are headache, sleep disturbances, and gastrointestinal disorders. The possibility of

more serious adverse effects is indicated in isolated case study reports and data from

spontaneous reporting schemes, but causality is often difficult to determine from the

evidence provided. Combination products containing ginseng as one of several

constituents have been associated with serious adverse events and even fatalities.

However, interpretation of these cases is difficult since ingredients other than Panax

ginseng may have caused the problems. Possible drug interactions have been reported

between Panax ginseng and warfarin, phenelzine, and alcohol. Collectively, these data

suggest Panax ginseng monopreparations are rarely associated with adverse events or

drug interactions. Combined preparations are more often associated with such events, but

causal attribution is usually not possible.

Although a large number of investigations examining the effects of ginseng have

been published, many of these studies have involved small numbers of participants,


30

including case study reports. Case study reports are limited in their representativeness.

They do not necessarily allow valid generalizations to the population from which they

came, and they are vulnerable to subjective biases. Case study reports may be selected

because of their dramatic rather than typical attributes, or because they neatly fit an

observer's pre-conceptions. Case study reports should encourage additional investigation

with a greater number of subjects. Results of case studies can be used as hypotheses to be

tested using rigorous experimental designs incorporating appropriate control and placebo

paradigms.

The efficacy and safety of ginseng have also been evaluated by Kitts and Hu

(2000) leading them to conclude “while some epidemiological or clinical studies have

reported indications of efficacy for specific health benefits or potential toxicity, there are

an equal number of studies that provide contradictory evidence” and further “this

situation has lead to questionable conclusions concerning specific health benefits or risks

associated with ginseng.” Ernst (2002) has also examined the risk-benefit profile of

several commonly used herbal therapies including ginseng and concluded that “well-

conducted clinical trials do not support the efficacy of ginseng to treat any condition” and

further “none of these herbal medicines are free of adverse effects.”

When reports of adverse effects from herbal preparations are carefully assessed, it

is often found the effects are not due to the herb(s) listed on the label, but rather the

effects are due to adulteration or contamination of the declared ingredients. A case of

ginseng-induced mania in a healthy 26-year-old male with no history of psychiatric

illness has been reported by Engelberg, McCutcheon, and Wiseman (2001). The


31

presenting symptom at the time of hospitalization was the patient’s increasingly bizarre

behavior. This individual had been consuming two to three capsules of Chinese red

Panax ginseng, 5 days per week, for 2 months in an attempt to boost his energy. The

product label claimed that each capsule contained the equivalent of 250 mg of ginseng

root. Laboratory analysis of the same brand of product revealed no evidence of controlled

drugs or other notable contaminants. The symptoms resolved following treatment and

discontinuation of the ginseng preparation, and the cause of the mania was attributed to

the patient’s use of ginseng.

Development of manic symptoms in a patient taking ginseng has been reported by

Vazquez and Aguera-Ortiz (2002). The patient, a 56-year-old woman with previous

affective disorder, and taking antidepressant medication, developed a manic episode

while consuming ginseng. Symptoms disappeared following treatment including

discontinuation of the ginseng supplement. But, the question that remains unanswered in

such cases is whether or not the development of mania was due to the antidepressant

drug, the ginseng, or the interaction of the drug and ginseng. A case of transient ischemic

attack secondary to hypertensive crisis related to the consumption of Panax ginseng has

been reported by Martinez-Mir, Rubio, Morales-Olivas, and Palop-Larrea (2004). The

patient, a 64-year-old man, complained of fugax amaurosis on two occasions with arterial

blood pressure readings of 200/120 and 220/130 mm Hg, respectively, following 13 days

of ginseng consumption. Blood pressure returned to its previous level one week after

cessation of the Panax ginseng. One year later at follow-up, the patient remained

normotensive.


32

Photosensitivity reaction in a woman using an herbal supplement containing

ginseng, goldenseal, and bee pollen has been described by Palanisamy, Halter, and Olson

(2003). This 32-year-old woman suffered a phototoxic reaction after taking a dietary

supplement containing ginseng, goldenseal, bee pollen, and other ingredients. The

condition slowly resolved following discontinuation of the supplement and treatment

with subcutaneous and topical corticosteroids. Although the individual ingredients in the

dietary supplement have not been associated with cases of photosensitivity it is possible

that the combination of ingredients may have interacted to cause the toxic reaction.

Caution is urged in the use of combined herbs and supplements in new formulations that

have not been evaluated in controlled trials.

A case of anaphylactic reaction due to ingestion of Asian ginseng syrup in a 20-

year-old male has also been reported by Wiwanitkit and Taungjaruwinai (2004). Since

ginseng is a widely consumed herb, potential adverse effects – such as allergic reaction,

need to be emphasized.

Ginseng and Eleutherococcus senticosis have also been reported to interact with

certain oral health drugs such as aspirin and corticosteroids, suggesting use of these

products may be associated with various adverse reactions that can influence oral health

and treatment. According to Abebe (2003), dentists and dental hygienists need to be

aware of these interactions and offer appropriate oral health care to individuals using

these substances.

A case of menstrual alterations related to ginseng consumption has been reported

by Palop-Larrea, Gonzalvez-Perales, Catalan-Oliver, Belenguer-Varea, and Martinez-Mir

(2000). A 48-year-old woman, who had never experienced menstrual disorders in the


33

past, was admitted following a 3-week history of metrorrhagia following self-medication

with three daily capsules for 2 months of a ginseng compound. A companion advised her

to take the ginseng to improve her work performance. The metrorrhagia disappeared 4

days after discontinuing ginseng administration. More recently, Kabalak, Soyal,

Urfalioglu, Saracoglu, and Gogus (2004) have also reported menometrorrhagia and

tachyarrhythmia following use of oral and topical ginseng for cosmetic reasons in a 39-

year-old female patient. The patient was advised to stop using ginseng capsules and

ginseng cosmetics and her menometrorrhagia did not recur during the following 6

months. Given the extensive literature documenting menstrual dysfunction among female

endurance athletes, extra caution may be warranted when using various ginseng

preparations. With the many adverse effects associated with the use of ginseng, all users

would be wise to exhibit caution.

Conclusions

Ginseng is one of the most popular herbal supplements in the world. It is widely used by

the general public to increase work capacity and output and by athletes to enhance

performance. In the present review we have provided an update of empirical research

published since our two earlier reviews by focusing primarily on the efficacy of ginseng

with respect to physical and athletic performance. We have updated the physiological

effects of ginseng and ginseng-related products on physical activity, stress, and fatigue in

humans; the psychological, behavioral, and cognitive effects; the quality, purity, and

bioavailability of ginseng products; and the adverse health effects, drug interactions, and

safety of ginseng.


34

While the effects of ginseng on pulmonary function, exercise capacity, and

chronic fatigue have been reported in several earlier studies, many of these investigations

were conducted with patients suffering from compromised pulmonary function and low

levels of exercise capacity. Also, older individuals, suffering from chronic fatigue, often

turn to herbal products such as ginseng for help in combating fatigue, while athletes often

use ginseng for prevention and treatment of overtraining. The studies reviewed here have

also been conducted with patients and elderly individuals and these results, when

obtained from ill and older adults, cannot be applied to healthy, young athletes.

Athletes are also known to use Panax ginseng or Eleutherococcus senticosus

believing these herbs decrease the incidence of colds and infections and enhance recovery

from intense training. However, while previous and recent investigations reveal that

ginseng and ginseng-related products may reduce inflammation and produce anti-stress

adaptogenic activity and excitability in mice and rats as well as enhance physical

performance, these effects are rarely evident in humans studied in well-designed

investigations. Several recent investigations also reveal that supplementation with

ginseng does not improve physical performance and recovery of individuals undergoing

exhaustive exercise.

The positive effects of ginseng and ginseng-related products on psychological

function, moods, behavior, stress reduction, and chronic pain in animals have been

reported in a few of the earlier studies in this area that we have reviewed. Findings from

recent investigations using animals generally tend to support these earlier reports.

However, while a few investigations reviewed here have demonstrated decreased levels

of stress, anxiety, and pain following administration of ginseng and ginseng-related


35

products to animals, ginseng administration in humans has not been shown to enhance

mood in healthy young adults.

In sports where quick decision-making is required, it is not unusual for athletes to

consume products thought to provide an advantage over the competition. Previous

research suggests chronic administration of ginseng can improve cognitive performance

in animals and in humans. However, while current research supports this general finding,

the ecological validity of applying such results, obtained in laboratory settings, to athletes

and athletic environments is questionable.

Many studies examining the pharmacological effects of ginseng and related

products on humans engaged in physical performance such as that pursued by athletes

frequently have not employed sound scientific design and methodology. For example,

small numbers of subjects completing studies may have been inadequate in providing the

statistical power needed to detect significant changes. There has also been a noticeable

lack of double-blind and placebo-controlled investigations. Many of the studies reporting

a positive influence of ginseng were supported by the supplier of the ginseng used in the

various studies, but this potential conflict of interest has not been clearly stated in the

published research. This is especially problematic where blind paradigms have not been

employed.

Variability in ginseng preparations is also a major concern as most dietary

supplements are not subject to the same regulations as pharmaceuticals, and these herbal

products may lack purity or potency. Hence, research involving herbal products,

including ginseng, is associated with major “sourcing” problems, and it is imperative that

investigators assay the content of products employed in experiments designed to quantify


36

efficacy. It is noteworthy that only a few of the investigations in the present review

included an assay of the actual content of the substances used in the experiment. And,

there has been little or no effort to confirm whether or not subjects have taken the

prescribed ginseng (i.e., compliance). This emphasizes the need for future investigations

in this area to use standardized preparations and methods.

It is important to recognize that adverse effects associated with ginseng

consumption have been reported. Ginseng is thought to be relatively safe, and the most

commonly experienced adverse effects are headache, sleep disturbances, and

gastrointestinal disorders. However, several recent reports on the adverse effects of

ginseng indicate that more severe outcomes can occur. These include ginseng-induced

mania, transient ischemic attack, photosensitivity reaction, anaphylactic reaction, and

menstrual dysfunction.

In summary, we conclude that despite attempts in recent investigations to improve

upon the scientific rigor used in examining the ergogenic properties of ginseng, many of

the same methodological shortcomings observed in earlier studies persist. Compelling

evidence in support of enhanced physical performance following ginseng administration

in humans participating in well-designed investigations remains to be demonstrated.


37

References Abebe, W. (2003). An overview of herbal supplement utilization with particular emphasis on possible interactions with dental drugs and oral manifestations. Journal of Dental

Hygiene, 77, 37-46. Anonymous (2005). Warning on imported ginseng. FDA Consumer, 39, 3. Asafu-Adjaye, E.B., & Wong, S.K. (2003). Determination of ginsenosides (ginseng saponins) in dry root powder form from Panax ginseng, Panax quinquefolius, and selected commercial products by liquid chromatography: interlaboratory study. Journal

of AOAC International, 86, 1112-23. Attele, A.S., Wu, J.A., & Yuan, C-S. (1999). Ginseng pharmacology: multiple constituents and multiple actions. Biochemical Pharmacology, 58, 1685-93. Bahrke, M.S., & Morgan, W.P. (1994). Evaluation of the ergogenic properties of ginseng. Sports Medicine, 18, 229-48. Bahrke, M.S., & Morgan, W.P. (2000). Evaluation of the ergogenic properties of ginseng: an update. Sports Medicine, 29, 113-33. Baranov, A.I. (1982). Medicinal uses of ginseng and related plants in the Soviet Union: recent trends in the Soviet literature. Journal of Ethnopharmacology, 6, 339-53. Bardia, A., Nisly, N.L., Zimmerman, M.B., Gryzlak, B.M., & Wallace, R.B. (2007). Use of herbs among adults based on evidence-based indications: findings from the National Health Interview Survey. Mayo Clinic Proceedings, 82, 561-6. Barna, P. (1985). Food or drug? The case of ginseng [letter]. Lancet II, 8454, 548. Besso, H., Kasai, R., Wei, J., Wang, J-F, Saruwatari, Y-I., Fuwa, T., & Tanaka. O. (1982). Further studies on dammarane-sapogenins of American ginseng, roots of Panax quinquefolium L. Chemical Pharmaceutical Bulletin, 30, 4534-38. Brekman, I.I. Eleutherococcus senticosus: a new medicinal herb of the araliaceae family. (1965). In K.K. Chen and B. Mukerji (Eds.). Pharmacology of oriental plants. (pp. 97-102). New York, NY: Macmillan Company. Cardinal, B.J., & Engels, H-J. (2001). Ginseng does not enhance psychological well-being in healthy, young adults: results of a double-blind, placebo-controlled, randomized clinical trial. Journal of the American Dietetic Association, 101, 655-60. Chase, P.J., Darby, L.A., Liang, M.T.C., & Morgan, A.I. (2000). Efficacy of Eleutherococcus senticosus (Siberian ginseng) as an ergogenic nutritional supplement [abstract]. Medicine and Science in Sports and Exercise, 32, S61. Choi, K.T. (2008). Botanical characteristics, pharmacological effects and medicinal components of Korean Panax ginseng C.A. Meyer. Acta Pharmacologica Sinica, 29, 1109-18. Chong, S.K.F., & Oberholzer, V.G. (1988) Ginseng: is there a use in clinical medicine? Postgraduate Medical Journal, 64, 841-6. CNN.com/WORLD. (November 21, 2001). Korean root spawns riches, cancer cure claims. http://asia.cnn.com/2001/WORLD/asiapcf/east/11/21/korea.ginseng.reut/index.html Coon, J.T., & Ernst, E. (2002). Panax ginseng: a systematic review of adverse effects and drug interactions. Drug Safety, 25, 323-44. Court, W.E. (1975). Ginseng: a Chinese folk medicine of current interest. Pharmacy

Journal, 214,180-1.


http://asia.cnn.com/2001/WORLD/asiapcf/east/11/21/korea.ginseng.reut/index.html

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Davydov, M., & Krikorian, A.D. (2000). Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. (Araliaceae) as an adaptogen: a closer look. Journal of Ethnopharmacology, 72, 345-93. Dragun, Z., Puntaric, D., Prpic-Majic, D., Bosnir, J., Gmajnic, R., & Klaric, M. (2003). Toxic metals and metalloids in dietetic products. Croatian Medical Journal, 44, 214-18. Elyakov, G.B., Strigina, L.I., Uvarova, N.I., Vaskovasky, V.E., Dzizenko, A.E., & Kochetkov, N.K. (1964). Glycosides from ginseng roots. Tetrahedron Letters, 48, 3591-7. Engelberg, D., McCutcheon, A., & Wiseman, S. (2001). A case of ginseng-induced mania. Journal of Clinical Psychopharmacology, 21, 535-36. Engels, H-J., Fahlman, M.M., & Wirth, J.C. (2003). Effects of ginseng on secretory IgA, performance, and recovery from interval exercise. Medicine and Science in Sports and

Exercise, 35, 690-96. Engels, H-J., Kolokouri, I., Cieslak, T.J., & Wirth, J.C. (2001). Effects of ginseng supplementation on supramaximal exercise performance and short-term recovery. Journal of Strength and Conditioning Research, 15, 290-95. Ernst, E. (2002). The risk-benefit profile of commonly used herbal therapies: Gingko, St. John’s Wort, ginseng, Echinacea, saw palmetto, and kava. Annals of Internal Medicine, 136, 42-53. Froiland, K., Koszewski, W., Hingst, J., & Kopecky, L. (2004). Nutritional supplement use among college athletes and their sources of information. International Journal of

Sport Nutrition and Exercise Metabolism, 14, 104-120. Gaffney, B.T., Hugel, H.M., & Rich, P.A. (2001a). The effects of Eleutherococcus senticosus and Panax ginseng on steroidal hormone indices of stress and lymphocyte subset numbers in endurance athletes. Life Sciences, 70, 431-42. Gaffney, B.T., Hugel, H.M., & Rich, P.A. (2001b). Panax ginseng and Eleutherococcus senticosus may exaggerate an already existing biphasic response to stress via inhibition of enzymes which limit the binding of stress hormones to their receptors. Medical

Hypotheses, 56, 567-72. Goulet, E.D.B., & Dionne, I.J. (2005). Assessment of the effects of eleutherococcus senticosus on endurance performance. International Journal of Sport Nutrition and

Exercise Metabolism, 15, 75-83. Gross, D., Shenkman, Z., Bleiberg, B., Dayan, B.M., Gittelson, M., & Efrat, R. (2002). Ginseng improves pulmonary functions and exercise capacity in patients with COPD. Monaldi Archives Chest Diseases, 57, 242-46. Harkey, M.R., Henderson, G.L., Gershwin, M.E., Stern, J.S., & Hackman, R.M. (2001). Variability in commercial ginseng products: an analysis of 25 preparations. American

Journal Clinical Nutrition, 73, 1101-06. Healing Herbs and Natural Remedies. (April 15, 2008). Top selling herbal products in the U.S. http://www.herbsandnaturalremedies.com/top-sellers.htm Hon, C., Chow, Y., Zeng, F., & Leung, F.C.C. (2003). Genetic authentication of ginseng and other traditional Chinese medicine. Acta Pharmacologica Sinica, 24, 841-46. Hong, D.Y., Lau, A.J., Yeo, C.L., Liu, X.K., Yang, C.R., Kob, H.L., & Hong, Y. (2005). Genetic diversity and variation of saponin contents in Panax notoginseng roots from a single farm. Journal of Agricultural and Food Chemistry, 53, 8460-7.


http://www.herbsandnaturalremedies.com/top-sellers.htm

39

Hou, J.P. (1977). The chemical constituents of ginseng plants. Comparative Medicine

East West, 5, 123-45. Hsu, C.C., Ho, M.C., Lin, L.C., Su, B., & Hsu. M-C. (2005). American ginseng supplementation attenuates creatine kinase level induced by submaximal exercise in human beings. World Journal of Gastroenterology, 11, 5327-31. Hu, S.Y. (1976). The genus Panax (ginseng) in Chinese medicine. Economic Botany, 30, 11-28. Iida, Y., Tanaka, O., & Shibata, S. (1968). Studies on saponins of ginseng: the structure of ginsenoside-Rg1. Tetrahedron Letters, 52, 5449-53. Iwabuchi, H., Yoshikura, M., Ikawa, Y., & Kamisako, W. (1987). Studies on the sesquiterpenoids of Panax ginseng C.A. Meyer: isolation and structure determination of sesquiterpene alcohols, panasinsanols A and B. Chemical Pharmaceutical Bulletin, 35, 1975-81. Iwabuchi, H., Yoshikura, M., & Kamisako, W. (1988). Studies on the sesquiterpenoids of Panax ginseng C.A. Meyer II: isolation and structure determination of ginsenol, a novel sesquiterpene alcohol. Chemical Pharmaceutical Bulletin, 36, 2447-51. Kabalak, A.A., Soyal, O.B., Urfalioglu, A., Saracoglu, F., & Gogus, N. (2004). Menometrorrhagia and tachyarrhythmia after using oral and topical ginseng. Journal of

Womens Health, 13, 830-3. Kang, H.Y., Kim, S.H., Lee, W.J., & Byrne, H.K. (2002). Effects of ginseng ingestion on growth hormone, testosterone, cortisol, and insulin-like growth factor 1 responses to acute resistance exercise. Journal of Strength and Conditioning Research, 16, 179-83. Kasai, R., Yamaguchi, H., & Tanaka, O. (1987). High-performance liquid chromatography of glycosides on a new type of hydoxyapatite column. Journal of

Chromatography, 407, 205-10. Kennedy, D.O., & Scholey, A.B. (2003). Ginseng: potential for the enhancement of cognitive performance and mood. Pharmacology Biochemistry and Behavior, 75, 687-700. Kennedy, D.O., Scholey, A.B., & Wesnes, K.A. (2001a). Dose dependent changes in cognitive performance and mood following acute administration of ginseng to healthy young volunteers. Nutritional Neuroscience, 4, 295-310. Kennedy, D.O., Scholey, A.B., & Wesnes, K.A. (2001b). Differential, dose dependent changes in cognitive performance following acute administration of Ginkgo biloba/Panax ginseng combination to healthy young volunteers. Nutritional Neuroscience, 4, 399-412. Kennedy, D.O., Scholey, A.B., & Wesnes, K.A. (2002). Modulation of cognition and mood following administration of single doses of Ginkgo biloba, ginseng, and a ginkgo/ginseng combination to healthy young adults. Physiology and Behavior, 75, 739-51. Kennedy, D.O., Scholey, A.B., Drewery, L., Marsh, L.R., Moore, B., & Ashton, H. (2003). Electroencephalograph effects of single doses of Ginkgo biloba and Panax ginseng in healthy young volunteers. Pharmacology Biochemistry and Behavior, 75, 701-9. Khan, I.A., Allgood, J., Walker, L.A., Abourashed, E.A., Schenk, D., & Benson, W.H. (2001). Determination of heavy metals and pesticides in ginseng products. Journal of

AOAC International, 84, 936-9.


40

Kim, S.H., Park, K.S., Chang, M.J., & Sung, J.H. (2005). Effects of Panax ginseng extract on exercise-induced oxidative stress. Journal of Sports Medicine and Physical

Fitness, 45, 178-182. Kitts, D.D., & Hu, C. (2000). Efficacy and safety of ginseng. Public Health Nutrition, 3(4A), 473-85. Korea Herald. (Wednesday March 20, 2002). Korea promoting international food standard for ginseng. Krochmal, R., Hardy, M., Bowerman, S., Lu, Q-Y, Wang, H-J, Elashoff, R.M., & Heber, D. (2004). Phytochemical assays of commercial botanical dietary supplements. Evidence-

based Complementary Alternative Medicine, 1, 305-13. Kulaputana, O, Thanakomsirichot, S., & Anomasiri, W. (2007). Ginseng supplementation does not change lactate threshold and physical performances in physically active Thai men. Journal of the Medical Association of Thailand, 90, 1172-9. Liang, M.T.C., Podolka, T.D., & Chuang, W.J. (2005). Panax Notosginseng supplementation enhances physical performance during endurance exercise. Journal of

Strength and Conditioning Research, 19, 108-14. Liberti, L.E., & Der Marderosian, A. (1978). Evaluation of commercial ginseng products. Journal of Pharmaceutical Sciences, 67, 1487-9. Lieberman, H.R. (2001). The effects of ginseng, ephedrine, and caffeine on cognitive performance, mood, and energy. Nutrition Reviews, 59, 91-102. Lim, W., Mudge, K.W., & Vermeylen, F. (2005). Effects of population, age, and cultivation methods on ginsenoside content of wild American ginseng (Panax quinquefolium). Journal of Agricultural and Food Chemistry, 53, 8498-505. Martinez-Mir, I., Rubio, E., Morales-Olivas, F.J, & Palop-Larrea, V. (2004). Transient ischemic attack secondary to hypertensive crisis related to Panax ginseng. Annals of

Pharmacotherapy, 38, 1970. Matsuda, H., Namba, K., Fukuda, S., Tani, T., & Kubo, M. (1986). Pharmacological study on Panax ginseng C.A. Meyer: III. Effects of red ginseng on experimental disseminated intravascular coagulation. (2) Effects of ginsenosides on blood coagulative and fibrinolytic systems. Chemical Pharmaceutical Bulletin, 34, 1153-7. Pailisin, T.E., & Stacy, J.J. (2006). Ginseng: is it the root? Current Sports Medicine

Reports, 5, 210-4. Palanisamy, A., Halter, C. & Olson, K.R. (2003). Photosensitivity reaction in a woman using an herbal supplement containing ginseng, goldenseal, and bee pollen. Journal

Toxicology Clinical Toxicology, 41, 865-67. Palop-Larrea, V., Gonzalvez-Perales, J.L., Catalan-Oliver, C., Belenguer-Varea, A,, & Martinez-Mir, I. (2000). Metrorrhagia and ginseng. Annals of Pharmacotherapy, 34, 1347-8. Petkov, V.D., Yinglin, C., Todorov, I., Lazarova, M., Getova, D., Stancheva, S., & Alova, L. (1992). Behavioral effects of stem-leaves extract from Panax ginseng C.A. Meyer. Acta Physiologica Pharmacologica Bulgarica, 18, 41-8. Petroczi, A., & Naughton, D.P. (2008). The age-gender-status profile of high performing athletes in the UK taking nutritional supplements: lessons for the future. Journal of the

International Society of Sports Nutrition, 5, 2. Phillipson, J.D., & Anderson. L.A. (1984). Ginseng: quality, safety, and efficacy? Pharmaceutical Journal, 232, 161-5.


41

Pietta, P., Mauri, P., & Rava, A. (1986). Improved high-performance liquid chromatographic method for the analysis of ginsenosides in Panax ginseng extracts and products. Journal Chromatography, 356, 212-19. Popov, I.M., & Goldwag, W.J. (1973). A review of the properties and clinical effects of ginseng. American Journal Chinese Medicine, 1, 263-70. PRWeb Press Release Newswire. (February 25, 2008). World herbal supplements and remedies market to reach US$22.9 billion by 2010, according to new report by Global Industry Analysts, Inc. http://www.prweb.com/releases/herbal_supplements/herbal_remedies/prweb707734.htm Raman, O., Patino, L.C. & Nair, M. (2004). Evaluation of metal and microbial contamination in botanical supplements. Journal of Agricultural and Food Chemistry, 52, 7822-27. Reay, J.L., Kennedy, D.O., & Scholey, A.B. (2006). Effects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained “mentally demanding” tasks. Journal of Psychopharmacology, 20, 771-81. Scholey, A.B., & Kennedy, D.O. (2002). Acute, dose-dependent cognitive effects of Ginkgo biloba, Panax ginseng and their combination in healthy young volunteers: differential interactions with cognitive demand. Human Psychopharmacology, 17, 35-44. Shibata, S., Fujita, M., Itokawa, H., Tanaka, O. & Ishii, T. (1963). Studies on the constituents of Japanese and Chinese crude drugs: XI. Panaxadiol, a sapogenin of ginseng roots. Chemical Pharmaceutical Bulletin, 11, 759-61. Shibata, S., Tanaka, O., Soma, K., Iida, Y., Ando, T., & Nakamura, H. (1965). Studies on saponins and sapogenins of ginseng: the structure of panaxatriol. Tetrahedron Letters, 3, 207-13. Sievenpiper, J.L., Arnason, J.T., Vidgen, E., Leiter, L.A., & Vuksan, V. (2004). A systematic quantitative analysis of the literature of the high variability in ginseng (panax spp.): should ginseng be trusted in diabetes? Diabetes Care, 27, 839-40. Slater, G., Tan, B., & Teh, K.C. (2003). Dietary supplementation practices of Singaporean athletes. International Journal of Sport Nutrition Exercise Metabolism, 13, 320-32. Stavro, P.M., Woo, M., Heim, T.F., Leiter, L.A., & Vuksan, V. (2005). North American ginseng exerts a neutral effect on blood pressure in individuals with hypertension. Hypertension, 5, 406-411. Sundgot-Borgen, J., Berglund, B., & Torstveit, M.K. (2003). Nutritional supplements in Norwegian elite athletes – impact of international ranking and advisors. Scandinavian

Journal of Medicine and Science in Sports, 13, 138-44. Tanaka, O., Nagai, M., &. Shibata, S. (1966). Chemical studies on the Oriental plant drugs: XVI. The stereochemistry of protopanaxadiol, a genuine sapogenin of ginseng. Chemical Pharmaceutical Bulletin, 14, 1150-6. Tawab, M.A., Bahr, U., Karas, M., Wurglics, M., & Schubert-Zsilavecz. M. (2003). Degradation of ginsinosides in humans after oral administration. Drug Metabolism and

Disposition, 31, 1065-71. United States Department of Agriculture. The Farm Security and Rural Investment Act of 2002 – Public Law 107-17. http://www.usda.gov/farmbill2002/. USA Today. (1997). Ginseng warning. Dec. 19; 3A.


http://www.prweb.com/releases/herbal_supplements/herbal_remedies/prweb707734.htm

http://www.usda.gov/farmbill2002/

42

Vazquez, I., & Aguera-Ortiz, L.F. (2002). Herbal products and serious side effects: a case of ginseng-induced manic episode. Acta Psychiatrica Scandinavica, 105, 76-77. Vogler, B.K., Pittler, M.H., & Ernst, E. (1999). The efficacy of ginseng. A systematic review of randomised clinical trials. European Journal Clinical Pharmacology, 55, 567-75. Wenkui, L., Chungang, G., Zhang, H., Awang, D.V.C., Fitzloff, J.F., Fong, H.H.S., & van Breeman, R.B. (2000). Use of high-performance liquid chromatography – tandem mass spectrometry to distinguish Panax ginseng C.A. Meyer (Asian ginseng) and Panax

quinquefolius L. (North American ginseng). Analytical Chemistry, 72, 5417-22. Williams, L.O. (1957). Ginseng. Economic Botany, 11, 344-8. Wiwanitkit, V., & Taungjaruwinai, W. (2004). A case report of suspect ginseng allergy. Medscape General Medicine, 6, 9. Yamaguchi, H., Kasai, R., Matsuura, H., Tanaka, O., & Fuwa, T. (1988). High-performance liquid chromatographic analysis of acidic saponins of ginseng and related plants. Chemical Pharmaceutical Bulletin, 36, 3468-73. Yuan, C.S., Wang, X., Wu, J.A., Attele, A.S., Xie, J-T, & Gu, M. (2001). Effects of Panax quinquefolius L. on brainstem neuronal activities: comparison between Wisconsin-cultivated and Illinois-cultivated roots. Phytomedicine, 8, 178-83. Ziegler, P.J., Nelson, J.A., & Jonnalagadda, S.S. (2003). Use of dietary supplements by elite figure skaters. International Journal of Sport Nutrition and Exercise Metabolism, 13, 266-76, 2003. Ziemba, A.W., Chmura, J., Kaciuba-Uscilko, H., Nazar, K., Wisnik, P., & Gawronski, W. (1999). Ginseng treatment improves psychomotor performance at rest and during graded exercise in young athletes. International Journal of Sport Nutrition, 9, 434-42.


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Table 1. Effects on physical activity, stress, and fatigue.

Reference Participants N (gender) Ginseng Type Duration Data Collected Results

Gaffney et al. [2001a]

Male athletes 30 P.ginseng

Eleutherococcus

senticosus

6 weeks Cortisol, testosterone, T/C ratio, other immune system variables

Increased hormonal indices of stress

Engels et al. [2003]

Active, healthy adults

10 (M) 17 (F)

P.ginseng C.A. Meyer 400 mg/d G115

8 weeks Wingate test, peak power, recovery HR

No improvement in physical performance and HR recovery

Kang et al. [2002]

Male college students

8 Korean red ginseng root extract

1 day hGH, testosterone, cortisol, IGF-1

No anabolic effects

Chase et al. [2000]

8 (M) 3 (F)

Eleutherococcus

senticosus 900 mg/d

14 days Volitional exhaustion, oxygen consumption, expired volume air, ventilatory equivalent for oxygen, RER, HR, RPE, recovery lactate

No significant differences except for lactate

Hsu et al. [2005]

Active, male college students

13 Panax

quinquefolium 1600 mg/d

4 weeks Time to exhaustion, oxygen pulse, creatine kinase, lactate

No enhancement of aerobic work capacity, decreased leakage of creatine kinase during exercise

Kim et al. [2005]

Healthy males 7 P.ginseng extract 2g, 3x/d

8 weeks Volitional exhaustion, VO2max, HR, exercise duration

Facilitates recovery from exhaustive exercise

Liang et al. [2005]

Untrained, young adults

15 (M) 14 (F)

P. notoginseng 1,350 mg/d

30 days Time to exhaustion, blood pressure, oxygen consumption

Endurance time improved >7 minutes, decreased BP and oxygen consumption

Engels et al. [2001]

Active, healthy female adults

19 P. ginseng C.A. Meyer 400 mg/d G115

8 weeks Wingate test, peak anaerobic power, mean anaerobic output, rate of fatigue, post exercise HR

No ergogenic benefits

Kulaputana et al. [2007]

Physically active young males

57 Korean ginseng 3 gm

8 weeks Lactate threshold, exercise heart rate, total exercise time, peak power output

No ergogenic benefit

BP = blood pressure; F = female; hGH = human growth hormone; HR = heart rate; IGF-1 = insulin-like growth factor-1; M = male; RER = respiratory exchange ratio; RPE = rating of perceived exertion; VO2 = maximal oxygen uptake.


44

Table 2. Psychological, behavioral, and cognitive effects.

Reference Participants N (gender) Ginseng Type Duration Data Collected Results

Cardinal & Engels [2001]

Healthy, young adults

43 (M) 40 (F)

P.ginseng

200 or 400 mg 8 weeks Psychological

well-being No effect

Kennedy et al. [2001a]


20 200, 400, or 600 mg G115

1 day Mood and cognitive performance

Modulation of mood, no linear dose response effect

Kennedy et al. [2001b]


10 (M) 10 (F)

320, 640, or 960 mg combination G115 and Ginkgo biloba (GK501)


Improved cognitive performance

Kennedy et al. [2002]


5 (M) 15 (F)

360 mg Ginkgo

biloba, 400 mg ginseng, or 960 mg combination


Improved cognitive performance

Kennedy et al. [2003]

Health, young volunteers

5 (M) 15 (F)

360 mg Ginkgo

biloba or 200 mg P. ginseng

1 day EEG Modulation of cerebroelectrical activity

Ziemba et al. [1999]

Young, male soccer players

15 350 mg/d ginseng

6 weeks Psychomotor performance

Decreased reaction times

Reay et al. [2006]


27 P. ginseng 1 day Cognitive performance

Enhanced cognitive performance

EEG = electroencephalogram; F = female; M = male.


is ginseng an ergogenic aid? - human kinetics several species of ginseng are known to exist:...

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