A diet lacking in an omega-3 fatty acid, predominantly found in fish, may cause the brain to age faster and lose some of its memory and thinking abilities, according to the results of a study released today by the journal Neurology.
Researchers at the University of California at Los Angeles, and other institutions, studied 1,575 men and women age 67, on average, who were free of dementia. All underwent MRI brain scans and tests that measured mental function, body mass and the levels of omega-3 fatty acids, mainly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in their red blood cells.
Participants whose DHA levels were in the lowest 25 percentile had lower brain volumes compared to participants who had higher DHA levels, according to the report. Those whose omega-3 fatty acids were all in the bottom 25 percent scored lower on tests of visual memory and executive function, such as problem solving, multitasking, and abstract thinking. The MRI results showed a lower brain volume that represents a change equivalent to approximately 2 years of structural brain aging, the researchers reported.
Bottom line The finding of a link between lower blood levels of omega-3 fatty acids and markers of accelerated brain aging must be confirmed in follow-up research. Meanwhile, many population-based studies suggest that increased fish consumption may lower the risk of dementia and cognitive decline. As we’ve previously reported, most people can get enough omega3s by eating fatty fish—such as salmon and sardines, which are also low in mercury—at least twice a week. For advice on fish oil supplements, see “Is fish oil right for you?”