APA Dictionary of Psychology

a group of polyunsaturated fatty acids—primarily, alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid—that are important for such bodily functions as brain development, muscle activity, digestion, fertility, and cell division and growth. Omega 3s are found in fatty fish and shellfish and in certain vegetable oils (e.g., canola, soybean). They are also available as dietary supplements, which may contain either fish oil or flaxseed oil. These supplements are now among the most commonly taken nonvitamin, nonmineral natural supplements in the United States, but the evidence on their potential benefits is conflicting. For example, they appear to have modest usefulness in relieving symptoms of rheumatoid arthritis and in reducing the risk of age-related macular degeneration but to be ineffective in slowing diseases of the brain and nervous system (e.g., multiple sclerosis). Moreover, although there is good evidence that seafood rich in omega-3 fatty acids is important in a heart-healthy diet, taking omega 3s in supplement form has not definitively been shown to protect against heart disease. Also called n-3 fatty acids.