PITTSBURGH—Docosahexaenoic acid (DHA) is the principal long-chain omega-3 polyunsaturated fatty acid (PUFA) in the brain and plays a variety of critical roles in neural health and cognitive function; however, research findings have been contradictory on its role in addressing cognitive decline. The PUFA Newsletter reported on a study out of the University of Pittsburgh that explored the relationship between blood levels of omega-3 PUFAs and five major dimensions of cognitive performance (J Nutr. 2010 Apr;140(4):848-53; DOI:10.3945/jn.109.119578). Researchers took blood samples and conducted neuropsychological tests on 280 men and women aged 30 to 54 years; the assessments evaluated nonverbal reasoning and mental flexibility, attention and concentration, general memory, working memory and verbal knowledge, and processing.
Of the three omega-3s, DHA was most strongly related to cognitive function. Eicosapentaenoic acid (EPA) was significantly related to three subset scores of working memory, and alpha-linolenic acid (ALA) was unrelated to any cognitive score. DHA was significantly related to nonverbal reasoning, logical memory, and four dimensions of working memory and vocabulary; the relationships for nonverbal reasoning, composite working memory and several other tests remained significantly related to phospholipid DHA after taking education levels and vocabulary into account. The responses for matrix reasoning and composite working memory scores were dose-dependent.
