Memory, concentration, omega-3 are effective?
The fish oil supplements (omega-3) had no effect on mental abilities in a vast British study, published in the American Journal of Clinical Nutrition, comparing their effects on mental functions with those of a placebo (inactive product) for 2 years.
Alan Dangour the London School of Hygiene and Tropical Medicine and colleagues conducted the study with nearly 900 health seventies. It is the longest study to date with placebo.
The participants took a combination of 200 mg of omega-3 type eicosapentaenoic acid (EPA) and 500 mg of type docosahexaenoic acid (DHA) daily or placebo (olive oil).
After two years, participants taking the supplements actually had blood levels of omega-3 higher but no difference was found between the two groups on cognitive decline, different types of memory, concentration, speed of thought, reaction times, …
But, says the researcher, cognitive decline occurs over several years and, although it is the longest study of its kind, it is possible that it was not long enough for beneficial have been detected.
Omega-3 have been linked to cognitive benefits in observational studies that do not compare their effectiveness to that of placebo. A recent study of six months with placebo did not show any positive effects.