Eating oily fish may not help prevent dementia in old age, say U.K. researchers who studied data from a trial of more than 800 older people.
Initially, the researchers at the London School of Hygiene and Tropical Medicine found a significant association between eating a couple of portions of oily fish per week and higher scores on tests of cognitive function, BBC News reported.
However, that association almost vanished when the researchers factored in education and psychological health. The finding, published in The Journal of Nutrition, Health and Aging, challenges previous research suggesting that oily fish may help prevent dementia.
"The evidence on this has always been sporadic," said study leader Dr. Alan Dangour, BBC News reported. "What this shows is there is a link between people who eat oily fish and better cognitive function, but if you adjust for education and mood, this relationship goes, so it's not at all clear that healthy older people get any benefit from eating fish oil."