The studies were published last month in the American Journal of Clinical Nutrition. While no direct links between consumption of fish/omega-3 fatty acids and cognitive function was established, there is growing evidence of such an association, according to the Friedman School of Nutrition, Science and Policy at Tufts University in Boston, which provided an accompanying editorial in the journal.
The first study- of more than 2,000 elderly people in Norway- found that those who ate more than 10 grams of fish per day had markedly better test scores and a lower prevalence of poor cognitive performance than those who ate less than 10 grams of fish per day. People who ate about 75 grams per day had the best scores.
A study of 404 people from Holland, aged 50-70, found that higher plasma concentrations of omega-3 fatty acid at baseline were associated with a lower decline in several cognitive measures over a three year period.
The last study found a strong and consistent association between circulating concentrations of the omega-3 fatty acid eicosapentaenoic acid and physical health in 2,400 people from New Zealand, but a less compelling link between omega-3 fatty acids and mental health.