The largest ever trial of omega-3 fish oil supplements has found no evidence that they offer any benefits for cognitive function in older people.
The study, appearing in the American Journal of Clinical Nutrition, investigated the effects of taking omega-3 long-chain polyunsaturated fatty acid supplements over a two year period on the cognitive function of participants aged 70-80 years. Other studies have previously suggested that high intakes of omega-3 fatty acids are important for the maintenance of good cognitive health in later life.
The study involved 867 participants aged 70-80 years who all had good cognitive health at the start of the study. The participants were randomly assigned into two groups, one of which received fish oil capsules while the other group received a placebo for two years.
After two years, those participants receiving fish oil capsules had significantly higher levels of omega-3 fatty acids in their blood than those participants receiving placebo capsules. However, cognitive function did not change over the course of the study in either group of participants and there was no evidence that the consumption of omega-3 fatty acids had a benefit for cognitive function in older people.
"From the data we have collected in the OPAL study there is no evidence of an important benefit for memory or concentration of increased omega-3 fatty acid consumption over a two year period among older people with good cognitive health," said study leader Dr. Alan Dangour.
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Source: London School of Hygiene & Tropical Medicine