In a previous post we wrote about the negative influence of lead on brain development. It is still a serious issue even if the banning of leaded petrol was a great step forward in remediating the problem long-term. But it is not all doom and gloom. It is possible to help brain development along or at least make sure that we retain normal brain health. The beneficial substances are omega-3 fatty acids. It has been known since the 1930s that omega-3 fatty acids are needed in the diet to support normal growth and development, but appreciation of their health benefits took a dramatic step forward during the 1990s.
There are three omega−3 fatty acids that are important in human physiology: α-linolenic acid (18:3, n−3; ALA), eicosapentaenoic acid (20:5, n−3; EPA), and docosahexaenoic acid (22:6, n−3; DHA). They have either 3, 5, or 6 double bonds in a carbon chain of 18, 20, or 22 carbon atoms, respectively. Although the body can convert short-chain omega−3 fatty acids to long-chain forms (EPA, DHA), the efficiency is a low 5% in men, but greater in women, possibly to support the demands of the foetus and neonate for DHA.
EFSA supports health claims for DHA
Let’s first focus on DHA. It is the major structural lipid in brain tissue and the central nervous system, and the membrane lipids of brain grey matter and the retina contain very high concentrations of DHA. Since it is an essential fatty acid, that is it cannot be formed by the body except in very limited amounts from ALA, the praise of foods with reasonable levels of DHA is no surprise. In fairly rare support in the health claims area, the European Food Safety Authority (EFSA) in 2011 noted that there was a well established connection between DHA and brain function. EFSA concluded that a cause and effect relationship had been established between the consumption of DHA and the maintenance of normal brain function. It considered that in order to bear such health claim, foods should contain 250 mg of DHA in one or more servings.
So how are consumers reacting? A little surprisingly by increasing their intake of omega-3 supplements, not fish and seafood that naturally contain high levels of omega-3 fatty acids. Although other foods with added omega-3 fatty acids like spreadable oils and fats, fish fingers and fortified milk have appeared on the market, for adults sales of omega-3 supplements are about five times higher than sales of foods with added omega-3 counted on a value basis according to Nutraingredients.
However, the situation is different for young children. Here it is clear that parents are determined to optimise their children’s brain development with sales of baby milk formula completely dominated by products with added DHA.
Keeping a healthy brain at old age
It is expected that an ageing global consumer base will drive increased sales of foods with added omega-3 fatty acids as consumers start to realise their benefits. There is potential to target a wide range of brain-health related concerns, including depression. For more than a decade, studies have pointed to an association between fish consumption and depression. Across the globe, rates of depression are lower in populations that eat more fish, particularly omega-3 rich fish such as salmon, tuna, sardines and mackerel. Studies have also shown that omega-3 levels are lower in people with depression than in people without. A 2012 study of elderly people with mild cognitive impairment showed that increasing the intake of omega-3 fatty acids reduced depressive symptoms and the risk of progressing to dementia.
There might be differences in the effect of different omega-3 fatty acids. A review published in the journal of the American College of Nutrition in 2009 found that studies that used pure DHA or more than 50% DHA reported no effect on depression. Studies using pure EPA or more than 50% EPA found that symptoms improved. On the other hand higher levels of DHA seemed to be able to prevent post-partum depression. So they seem to both be essential to good health, but with slightly different effects. While good sources for ALA are flax seeds and walnuts, fish and seafood and omega-3 enriched eggs are the main food sources for EPA and DHA. And by the way there are many other health effects associated with omega-3 fatty acids than brain health. So keep the good oil flowing.
- Omega-3 Overview (purevitamins.com.au)
- New evidence: Omega-3 fatty acids fight cancer (foodconsumer.org)
- the incredible benefits of omega-3 fatty acids (thefitchronicles.com)
- And the beat goes on…: The reliable heartbeat of hibernators (eurekalert.org)
- Krill Oil vs Fish Oil (purevitamins.com.au)
- Fish oil helps prevent cardiovascular disease (foodconsumer.org)
- Omega-3 Fatty Acids May Boost (sobhealth.wordpress.com)
- Benefits of DHA in Pregnancy (dhainpregnancy.wordpress.com)
- 10 Foods That Boost Brain Function (americanlivewire.com)