Your mother always said that eating more fish would make you more brainy. Is there any possible truth in this?
In a scientific study on more than 100 children - selected on the basis that they were not fulfilling their potential - from 12 Durham schools, children were required to take a course of capsules with their meals for the duration of six months. The capsules given to children in the trial contained oils high in Omega 3 fats, which are found naturally in oily fish such as mackerel, salmon and sardines and in some plant crops such as rape seed. The children were subjected to regular tests to measure their co-ordination, concentration and academic ability.
Omega 3 fatty acids are known to help prevent heart disease and they can improve the condition of some patients with depression and bipolar disorder. But their effects on brainpower have not been investigated in the same depth.
The Durham trial was conducted by Dr Alex Richardson, of the University of Oxford and Madeleine Portwood, an educational psychologist for Durham LEA.
The results have not yet been published, but they are expected to show a statistically significant improvement in school performance in the group of children given Omega 3 supplements: according to Portwood, about 40% of children showed some clear improvement.
Richardson believes that conditions such as dyspraxia - characterised by poor physical co-ordination - dyslexia and attention deficit and hyperactivity disorder (ADHD) form a spectrum of associated conditions with some of the same underlying causes.
"Clinically, there is about 50% overlap between dyspraxia and dyslexia," says Richardson, "and both show a similar overlap with ADHD."
The Omega 3 fatty acid used in the Durham trial was Eicosapentaenoic acid (EPA). It may play an equally crucial role in brain function. EPA is found only at very low levels in the cell membranes; it seems to have a functional, rather than a structural role. EPA helps the body manufacture important substances which help improve blood flow around the body. They also seem to have controlling effects on hormones and the immune system, both of which are known to affect brain function.
Western diets contain very little Omega 3 fatty acid. Hydrogenation, the process used to give foods a long shelf life, removes them. But certain people may break down Omega 3 fatty acids faster than others. Some of the children who showed greatest improvement in the Durham trial might fall into this category.
But some quarters of the medical research community are deeply sceptical about the usefulness of so-called complementary therapies - the category of treatment in which fish oil supplements are often lumped.
Professor Richard Olson, a developmental psychologist at the University of Colorado, Boulder and an expert on the treatment of dyslexia, urged caution over a 'quick fix' syndrome towards the treatment of learning disorders.
"I hope they're right. I'm just sceptical of easy answers because there have been various schemes in the past and parents [with dyslexic children] go out and spend a lot of money on them. For many children with dyslexia, improvement can only be achieved with a lot of hard work," says Olson..