We’ve all heard the hype about how wonderful fish oils are and how vegetarians and vegans are missing out on this vital brain food. So, what actually is the scientific evidence that fish oils can improve cognitive ability? Suprisingly, the limited evidence comes mainly from trials done using children with behavioural problems and is largely anecdotal.
The 2005 Durham-Oxford Study is the most cited work. In this study, 117 children with developmental coordination disorders (DCD) such as attention deficit/hyperactivity disorder (ADHD), dyslexia and dyspraxia were given a daily supplement of fatty acids. The treatment was a supplement containing 80 per cent fish oil and 20 per cent evening primrose oil in gelatine capsules. The daily dose of six capsules provided omega-3 fatty acids (558 mg of EPA and 174 mg of DHA) and the omega-6 fatty acid LA (60 mg), or olive oil (omega-9) as a placebo.
After three months of treatment, results showed significant improvements in reading, spelling and behaviour among those receiving the fish oil supplements. The researchers concluded that fatty acid supplements may be a safe, tolerable, effective treatment for improving academic progress and behaviour among children with DCD. In other words, children who are not fulfilling their potential may benefit from increasing their intake of essential fatty acids.
A follow-up trial was conducted in Durham more recently whereby three million fish oil capsules were given to 2,000 children over eight months to see if their GCSE results improved. Unfortunately the GCSE results were rather disappointing, which was not press-released by the County Council. In some very fast back-pedalling they said “…it was never intended, and the County Council never suggested, that it would use this initiative to draw conclusions about the effectiveness or otherwise of using fish oil to boost exam results”. So it seems fish oil was not the magic bullet Durham Council was looking for.
It is interesting to note that the fish oil capsules used in the Durham trial cost 80p per child, per day, rather more than the 65p Durham Council was spending per child per day on school meals at the time. In 2008 the cost of ingredients had risen, but only to 80p for a secondary school child per day. Rather than looking for an elusive magic bullet, improving the quality of school meals and education about diet and health might have been a better approach.
Many children in the UK eat such a substandard diet that nutritional deficiencies are inevitable. Correcting these deficiencies will in many cases improve the symptoms associated with that particular deficiency. This is not the same as saying fish oil will turn all kids into geniuses, which is exactly how the media interpreted the findings. “Council to include more fruit, vegetable and wholefoods in school meals” just doesn’t make such an impressive headline as “magic pill makes kids clever”.
The Joint Health Claims Initiative (JHCI) operated between 2000 and 2007 to ensure a level playing field for the food industry and to increase consumer protection by investigating the science behind health claims. It is no longer in operation as the EU Regulation on nutrition and health claims now verifies health claims. However, during the seven years of investigating health claims, the JHCI approved claims for soya protein, oats and reduced saturated fat all for their cholesterol-lowering effects and for wholegrain foods’ benefits to heart health. They also approved health claims for long chain omega-3 fats for maintaining a healthy heart. They did not approve any claims linking omega-3 fats (or fish oils) to cognitive ability.
Unfortunately misleading publicity from this and other research has encouraged companies to produce so-called functional foods such as St Ivel Advance Omega-3 milk. The advertisements implied that this milk may make children more intelligent because it contained omega-3 fatty acids from fish. The advertisements for this so-called ‘clever milk’ featured the celebrity gynaecologist Professor Robert Winston, lending kudos to the outlandish claims. But following complaints, the Advertising Standards Authority (ASA) ruled that the advertisements were misleading and the claims used for the benefits of the milk unproven. The ASA ruled that as the children in the trial had learning difficulties, there was no basis to claim there would be an improvement in the concentration of all children. Dairy Crest, the company behind the product, withdrew the adverts following the ruling. Read more about this here.
Although the Government maintains its position on recommending fish oils for heart health, it is clearly not convinced about cognitive benefits. The UK’s Food Standards Agency (FSA) states that: “Evidence on the cognitive benefits of the omega-3 fatty acids, EPA and DHA, which are found in fish oils, is currently uncertain”.
Common sense suggests that if the diet provides enough essential fatty acids, fish oils may have no additional effect on cognitive ability at all. Encouraging children to eat oily fish in the pursuit of cleverness may lead to health problems due to their potential exposure to pollutants and increases the strain on an already unsustainable resource…
Adapted from Fish-Free For Life, published by the Vegetarian & Vegan Foundation.