Understanding the potential of cognitive ingredients

Dr Carrie Ruxton

Freelance Dietitian

Cognitive health important across the lifecycle

Diet &

Supplements

Higher IQ Brain development

Support for learning Mental health Slower cognitive decline

Likely effects are different for different groups of people

Boosting via programming

Support for normal

Preventing disorders

Preventing or slowing decline

Nutrients with brain-related health claims

Claim Nutrient

Maternal intake contributes to

normal brain development of

foetus & breastfed infants

Docosahexaenoic acid (DHA)

Contributes to maintenance of

normal brain function (all ages)

DHA

Contributes to normal cognitive

function

Iodine, iron, zinc

Contributes to normal

psychological function

Biotin, folate, niacin, vitamins

B1, B6, B12, vitamin C,

magnesium

Contributes to normal mental

performance

Pantothenic acid

Vitamin D

Vitamin C

Biotin

DHA/EPA

Magnesium

B vitamins

Iron

Iodine

Folate

Food sources

Most evidence relates to long-chain omega 3 fatty acids

Fats

Monounsaturated

Omega 9 fats (olive oil)

Polyunsaturated

Omega 6 fats

(sunflower oil) Omega 3 fats

Shorter-chain

e.g. ALA

Longer-chain e.g. DHA, EPA

Saturated

Sources of DHA/EPA

• Oily fish e.g. salmon, tuna, mackerel, herring, trout (2-3.9g EPA/DHA per 140g portion)

• Seafood e.g. prawns (0.2g/portion)

• Red meat (~0.1g per 100g)

• Cod liver oil (vits A,D) (0.1-0.5g per daily dose)

• Fish body oil supplements (content as above)

• Specialist supplements for pregnancy, infants, elderly containing other nutrients

Recommendations

• General advice: 2 portions of fish per week, one of which should be oily (translates as 0.45g

DHA/EPA per day or 3g per week)

• Men and older women can have up to 4 portions of oily fish weekly

• Higher amounts recommended in US for therapeutic reasons e.g. 1g/d for heart health post-MI (AHA)

UK intakes below recommendations

0

50

100

150

200

250

300

350

400

450

mg

LC

n3

PU

FA

pe

r d

ay

4-10y 11-18y 19-64y 65y+

Male Female

UK rec = 450 mg per day

Bates et al. (2012); with thanks to Dr Rachael Gibbs, University of Reading.

Driven by low intakes of oily fish

0

20

40

60

80

100

120

140

1.5-3y 4-10y 11-18y 19-64y 65y+

gra

ms/

we

ek

NDNS, Bates et al (2011). Data include coated fish and fish dishes

Half of weekly target

DHA/EPA should be consumed directly from the diet as synthesis from ALA is inefficient and

inhibited by high n6 PUFA intakes

ALA/day Blood EPA Blood DHA

3 g + 53% + 4%

3 g + 45% + 21%

3.5 g + 60% + 2%

9.6 g + 0.02% + 0.5%

13.7 g + 138% + 14%

Only 5 out of 20 studies showed +ve effect on DHA

Brenna et al. (2009) Prost Leuk Essen Fatty Acids 80; 85–91.

HEALTH EFFECTS OF OMEGA 3 FATTY ACIDS

DHA present in a wide range of body tissues

Arterburn et al. (2008) Am J Clin Nutr 83: 1467S–76S.

Pregnancy

Evidence

• Foetal IQ programming

– mature sleep patterns

– better visual acuity

• Reducing risk of post-natal depression (emerging evidence)

Maternal supplementation with fish oil improves infant IQ

RCT; 341 women

took cod liver oil

from wk 18 of

pregnancy until 3

months post-birth;

Total LC PUFA

2.5g daily

Mental, sequential & simultaneous processing, non-verbal abilities

Helland et al (2003) Pediatrics 111, e39 –e44.

Evidence inconsistent

• RCT n=152 women suppl from 20th wk pregnancy until delivery 500mg DHA + 150mg EPA daily

• No sign if difference in cognitive function intervention vs. placebo offspring at 6.5y

• But children with better cognitive function more likely to have mothers with significantly higher DHA status during pregnancy.

Campoy et al (2011) Am J Clin Nutr 94: 1880S-1888S

Maternal EPA/DHA supplementation boosts levels in breast milk

Arterburn et al. (2008) Am J Clin Nutr 83: 1467S–76S.

Infanthood

Evidence

• Normal development of retina and brain

• Support for normal learning and development

• Enhanced cognitive function and IQ (emerging evidence)

Why DHA is vital in 1st year

Birth

Brain

continues to

grow at foetal

rate from

birth to ~6

months

DHA uptake

follows similar

trajectory until

~18 months

Cognitive improvements in preterm babies fed fatty acids

• RCT n=470, US pre-term babies

• Received AA+DHA vs. control formulae

• Significantly better visual acuity and motor skills at 6 months in suppl group

• Significantly better vocabulary comprehension at 14 months in supplemented group

O’Connor et al (2001). Pediatrics 108: 359-71.

Developmental improvements in term infants

• RCT n=56, US normal term babies

• Received formula supplemented with DHA or DHA/AA vs. control formula

• Followed up at 4, 12 and 18 months

• Mean increase of 7 points on the Mental Development Index in DHA+AA group

But evidence inconsistent

Birch et al (2000). Dev Med Child Neurol 42: 174-81.

Childhood

Evidence

• Supporting learning and behaviour

• Managing ADHD and behavioural disorders

• Enhancing cognitive function (emerging evidence)

Recent review

Ruxton (2011). Complete Nutrition 11: 23-24.

ADULTS AND OLDER AGE

Link with depression?

• Fish and n3 intakes inversely assoc with depression risk

• Low blood n3 levels found in depressed patients

• Yet, RCT to reduce depressive symptoms produced inconsistent results

• Why?

Risk of depression

Colangelo et al. (2009) Nutrition 25:1011-1019.

EPA performs better

Sublette et al. (2011) J Clin Psych 72: 1577-84. Martins (2009) J Am Coll Nutr 28: 525–542.

N=241 studies

DHA only

EPA only

Low EPA

High EPA

Cognitive decline

0 0.5 1 1.5<900

mg

1130

mg

1300

mg

1490

mg

1750

mg

Relative Risk of dementia

Emerging evidence

• Reducing speed of cognitive decline as people age

• Reducing long-term risk of dementia and Alzheimer’s

Morris et al (2003). Arch Neurol 60: 940–946; n=816 cohort study

*P<0.05

LCn3PUFA/d

6 month RCT in impaired elderly

• N=50 elderly with mild cognitive impairment

• Placebo vs. high EPA vs. high DHA for 6 months

• Significant differences after 6 months

Lower depression with EPA or DHA

Less cognitive impairment with DHA

Sinn et at (2012) British Journal of Nutrition (2012), 107, 1682–1693

Cochrane review of studies in healthy elderly inconclusive

• Systematic review of studies > 6 month in healthy, normal elderly people

• N=3536 participants taking part in 3 trials of LCn3PUFA suppl.

• No evidence of cognitive benefit

• However, participants in control and intervention groups experienced either small or no cognitive decline

OTHER NUTRIENTS

Intervention studies – older adults

Ref Who What Outcome

1 Post-stroke B complex; 3.4y No effect on cognitive fx

2 Impaired cognitive fx Folic acid, B12; 2y Improved cognitive fx

3 Psychol distress B complex; 2y Cognitive decline slower

4 Impaired cognitive fx B complex; 2y Brain atrophy lower

5 Healthy Zn; 6mo Better memory

6 Post-stroke Zn; 30d Neurological fx improved

7 Healthy elderly Zn, Cu, antiox; 7y No effect on cognitive fx

8 Alzheimer’s Vit D, E, K; 2y Slower functional decline

9 Healthy elderly Multivit/min; 1y No effect on cognitive fx

1. Hankey (2013) Stroke 44: 2232-9; 2. Walker (2012) AJCN 95: 194-203; 3. de Jager (2012) Int J

Geriatr Psychiatry 27: 592-600; 4. Smith (2010) PLoS One 5: e12244; 5. Maylor (2006) BJN 96: 752-

60; 6. Aquilani (2009) Nutr Neurosci 12: 219-25; 7. Yaffe (2004). Neurol 63: 1705-7; 8. Dysken (2014)

JAMA 311: 33-44; 9. McNeil (2007) Nutr J 6:10.

Other interventions

• Many studies providing vitamins and minerals to children in developing countries with most finding positive results for cognitive performance

• However, most multinutrient interventions in normal Western populations inconclusive

• Specific nutrients, particularly B vits, zinc, iron, seem to work when given to vulnerable groups e.g. elderly, cognitively impaired, AD, eating disorders

MAKING SENSE OF THE EVIDENCE

What is the potential of cognitive ingredients?

• Good evidence that certain vitamins and minerals support normal function

• Studies in future may well prove that certain nutrients boost function in vulnerable groups

Best evidence is for fatty acids

• Good evidence that EPA and DHA are vital for normal development and help maintain brain function throughout life

• Emerging evidence for programming effect in utero and support for learning during childhood

• Conflicting evidence in depression and prevention of dementia/cognitive decline due to

methodological issues (type of fatty acid, baseline

status and health of population)

Applications

• Supplements, especially fish oil supplements that are research backed and formulated blends, considering that oily fish intakes are so low

• Natural foods for supporting cognitive function e.g. fish, lean red meat, eggs, fruit, green leafy vegetables, nuts

• Fortified ‘brain health’ food and drink products – some already available with caffeine

Different needs at different life stages but all dependent on pre-existing

nutritional status

DHA, AA Iron, iodine, EPA, DHA

EPA, iron B vitamins; EPA

and DHA

Acknowledgment

Thanks to Equazen for sponsoring

me to give this talk