The study group was comprised of 1,575 subjects (average age 67) who did not suffer from dementia. They underwent magnetic resonance imaging (MRI) brain scans and were given tests to evaluate mental function and omega-3 fatty acid levels in their red blood cells. Their body mass index (BMI) was also calculated. Omega-3 fatty acids include the nutrients docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The investigators reported that individuals whose DHA levels were in the bottom 25% had lower brain volumes than those with higher DHA levels. Furthermore, individuals whose levels of all omega-3 fatty acids were in the bottom 25% scored lower on tests of visual memory and executive function, including problem-solving, multi-tasking, and abstract thinking.
The researchers noted that previous studies have reported that eating fatty fish reduces the risk of dementia; however, others studies have failed to confirm a protective association between a fish diet and maintenance of cognitive function. They noted that their study, which focused on middle-aged to elderly subjects who had no evidence of either a stroke or dementia, supported the association.
The study was supported by the National Heart, Lung, and Blood Institute's Framingham Heart Study and the National Institute on Aging.
From the March 1, 2012, Prepared Foods' Daily News.