ROLE OF OMEGA-3-FATTY-ACIDS IN HEALTH AND DISEASE

Dietary lipid interventions have an important role in modulating the o nset of autoimmunity, cardiovascular diseases and cancer. Many studies carried out in the past have established the adverse effects of satur ated fats in humans and in animal models. Based on these adverse effec ts, the consumption of vegetable oils containing both monounsaturated omega (omega)-9 and polyunsaturated fatty acids (rich in 18:2 omega-6) is rising significantly in the United States. The increased consumpti on of many vegetable oils particularly of omega-6 series is however to be viewed as pro-inflammatory and is suspected as one of the possible causes for the gradual rise in certain malignant tumors, rheumatoid a rthritis and autoimmune diseases primarily due to the increased produc tion of pro-inflammatory cytokines although its increased usage has re duced cardiovascular disease nearly 30% in the United States. Diets ba sed on omega-6 enriched oils can increase the level of linoleic acid i n tissue phosphoglycerides and are able to reduce cholesterol levels, yet these lipids usually tend to elevate excessive arachidonic acid (2 0:4 omega-6) levels. In contrast, omega-3 fatty acid-enriched fish oil (FO) and/or omega-3 precursors from certain vegetable oils (linolenic acid, 18:3 omega-3) are found to provide protection against cardiovas cular disease, rheumatoid arthritis, cancer and possibly against the s everity of viral infections. Nutritional modification of cellular func tions by dietary lipids with a balanced ratio of omega-6 and omega-3 f atty acids offers an attractive avenue to correct, modify and/or preve nt many patho-physiological processes in health and disease state and to reduce toxicity of drugs in many patients. The mediation of such ef fects is thought to be primarily achieved through alterations of cellu lar membranes composition and other endogenous lipid stores which may modify the functional activity of various receptors on plasma membrane s. In summary, the protective effects of omega-3 lipids have been expl ained based on changes in eicosanoid synthesis and the reduced risk of sudden death from cardiac arrhythmia, increased protection from ische mic myocardium, improved myocardial function and reduction of other ca rdiovascular and autoimmune disease risks. However, well-designed stud ies are still required to further define the key role of both combinat ion of omega-6 and omega-3 fatty acids, from marine and vegetable sour ces, both as a supplement to infant nutrition specifically for optimiz ing the development of cognitive function, and also as preventive meas ure for reducing the incidence of diseases of aging in rapidly growing elderly populations.