University of Pittsburgh researchers recruited men and women between 18 and 25 years-old to take an omega-3 fatty acid supplement daily for six months. The supplement contained 750 milligrams of docosahexaenonic acid (DHA) and 930 milligrams of eicosapentaenoic acid (EPA). Before and after the six-month supplementation period, researchers conducted positron emission tomography (PET) scans and blood sample analyses on the subjects, who also took tests to assess their working memory.
After six months of omega-3 fatty acid supplementation, the subjects performed better on the working memory test. The scientists noted that this is consistent with previous research showing that increased DHA may improve cognitive performance. However, the results lacked adequate evidence as to the mechanism behind the improvement of working memory.
The research team concluded that omega-3 fatty acids may result in better working memory. However, further study is needed to better understand the process and to confirm these findings.
Dietary sources of omega-3 fatty acids include fish oil and certain plant and nut oils. Fish oil contains both DHA and EPA, while some nuts (such as English walnuts) and vegetable oils (such as canola, soybean, flaxseed, linseed and olive oils) contain alpha-linolenic acid (ALA).
There is supportive evidence from multiple studies that suggests the intake of recommended amounts of DHA and EPA in the form of dietary fish or fish oil supplements lowers triglycerides; reduces the risk of death, heart attack, dangerous abnormal heart rhythms and strokes in people with known cardiovascular disease; slows the buildup of atherosclerotic plaques ("hardening of the arteries") and lowers blood pressure slightly. However, high doses may have harmful effects, such as an increased risk of bleeding. Although similar benefits have been proposed for alpha-linolenic acid, the scientific evidence is less compelling, and the beneficial effects may be less pronounced.
For more information about omega-3 fatty acids, please visit Natural Standard's Foods, Herbs & Supplements database.