Brain & Cognitive function!

Which supplements should you take to improve memory and concentration?

Although important for all cells of the body, an adequate supply of all nutrients is especially important for the health of the nerve cells of the brain every stage of life.

Essential brain nutrition

Brain tissue differs in its composition from others of the body. It is high in fat and cholesterol and is more specific in terms of its energy requirements than other organ tissues. So perhaps it is not surprising that the brain cells’ demands for certain nutrients are higher and more specific than those of other body cells. Nevertheless, it is only during the last decade that we have come to realise that certain key nutrients have a special function, at optimal levels of intake, in maintaining brain health and preventing age-related cognitive decline.

Optimal brain nutrition - vitamins and minerals

Higher intakes of nutrients are required as we get older, because of reduced nutrient absorption and enhanced elimination, so it is wise to take a comprehensive A-Z multi-vitamin and mineral supplement throughout later life. Such products are based on the government nutrient target intakes for adults to avoid deficiency disease (essentiality). Together with a healthy diet, such supplementation forms a firm basis of health by ensuring that nutrient deficiencies are avoided. However, target intakes based on essentiality do not address optimal nutrition of the brain. Their aims not only to avoid states of nutrient deficiency, but also to protect against the development of chronic diseases such as atherosclerosis (furring up of the arteries), which can reduce blood flow to the brain and trigger degenerative changes which lead to loss of mental function. To ensure optimal nutrition for the brain, higher levels of certain key nutrients, in particular the antioxidants such as vitamins C and E, may be needed. Indeed, higher intakes of these nutrients, along with folic acid, vitamin B12 and vitamin B6 have been shown to improve poor cognitive function in a six-year study of 137 elderly people.¹

Fatty Acids

Omega 3 fatty acids (DHA and EPA) are particularly important for the health of the brain. In fact, one of the omega 3 fatty acids called DHA (docosahexaenoic acid) is an essential structural component of brain cells, where it is the most prominent. The importance of DHA is seen throughout the lifecycle. In the new-born, DHA deficiency is associated with delayed visual and cognitive development. Low levels of DHA have been found in Alzheimer´s patients² and this fatty acid is increasingly being shown to be important for mental health in adults. For example, a recent study from Paris showed that low levels of omega 3 fatty acids in the blood were linked to greater cognitive decline in the elderly.³Although in younger adults, the precise role of DHA in brain function is still under investigation, studies are showing that low levels are linked to a number of mental problems, including anxiety and depression. Contrary to previous speculation, new evidence has shown that the body cannot make adequate amounts of DHA from flax seed oil.4 However, eating oily fish twice a week will provide a modest intake of DHA and additional supplementation with fish oil high in omega 3 fatty acids will ensure a steady and adequate supply. Fortunately, in the last few years, supplements of DHA derived from marine algae have also become available for vegetarians. The other important omega 3 fatty acid, called EPA, is highly beneficial in reducing risk of heart disease and inflammation, but unlike DHA, it is not a structural fatty acid and cannot replace it. The body can synthesise EPA (eicosapentaenoic acid) from flax seed oil, which is good news for vegetarians.

Phosphatidyl Serine

Phosphatidyl serine (PS) is not an essential nutrient since it can be made in the body. However, with age, the body´s synthesis of it can decline. PS is one of the building blocks of brain cell membranes and it protects against damage by a yet-unknown mechanism. Nevertheless, the evidence for a positive effect of PS on brain function is encouraging. One large study in Italy⁵ showed that elderly patients with loss of mental function supplemented with PS did better on cognitive tests that those on placebo, while another study with people with memory loss showed that PS gave improvement compared with a placebo. Further supportive evidence comes from animal studies and although notall human trials have shown such positive effects, all have shown PS to bevery safe when taken as a supplement.

Ginkgo

More evidence exists for the beneficial effect of ginkgo on mental function than for any herb for any body condition. Indeed, ginkgo is the most well-established herbal treatment for Alzheimer’s disease. Although the tree died out in Europe during the last great ice age, it survived in China and is now used extensively in cultivation as an ornamental. The herb has a long history of medicinal use in Germany, where it has been much researched. The number of double-blind, placebo-controlled human studies on the effects of ginkgo on mental health now exceed 50. The authors of the influential Cochrane review (2002),⁶ while calling for further studies, added: "Overall there is promising evidence of improvement in cognition and function associated with it." However, it is not only the elderly who might benefit from taking gingko. In the last five years, several studies have shown improvement in memory of short-term supplementation of healthy young people.

Conclusion

Every cell in the body requires a supply of vitamins and minerals and essential fatty acids. Brain cells are no different - so it is not surprising that people whose diets are low in essential nutrients often suffer problems with their mental health, including depression and anxiety. Low nutrient intake is all too common in modern life, as shown by major government surveys. Indeed, a large proportion of the population are not reaching the government-recommended targets for many essential nutrients. Taking a comprehensive A-Z multi-vitamin is one way of ensuring that essential targets for vitamins and minerals are met and is appropriate even for those eating healthily. However, optimal nutrition of the brain may require extra nutrients. Today, the study of nutrition and cognitive function is a rapidly growing field and it is likely that in the next few years further nutrients and herbs will be identified as important for mental function. In the meantime this article attempts to highlight the best of knowledge to date on natural approaches for the preservation of cognitive health.

¹ La Rue A et al. (1997). Am J Clin Nutr 65: 20.
² Tully AM et al. (2003). Br J Nutr 89: 483.
³ Heude B et al. (2003). Am J ClinNutr 77: 803.
⁴ Francois CA et al. (2003). Am J Clin Nutr 77: 226.
⁵ Cenacchi T et al. (1993). Aging 5: 123.
⁶ Birks J et al. (2002). Cochrane Database Syst Rev 4: CD003120.

Article issued: 27 August 2005

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Article by
Dr Ann Walker
Dr Ann Walker is Senior Lecturer in Human Nutrition in the Hugh Sinclair Unit of Human Nutrition at The University of Reading. She received her BSc in Biochemistry from the University of Bristol and her PhD in Nutrition & Food Science at the University of Reading. Ann is a member of the National Institute of Medical Herbalists (UK) and the College of Practitioners of Phytotherapy (UK). She now runs a clinic two days a week, where she treats patients suffering a wide variety of conditions with a combination of nutrition and herbal medicine. She is the author of several books on human nutrition & scientific papers. At the university, Ann's research focus is the investigation of the therapeutic effects of nutrients, including plants extracts, through randomised double-blind human studies. Studies have involved women's health (premenstrual symptoms, menopause), type II diabetes, hypertension and joint and digestive health.