N-3 fatty acids: priority for post-myocardial infarction clinical trials.

Abstract

Alarge body of data points to potential benefits of N-3 polyunsaturated fatty acids in reducing the risk of cardiovascular disease (CVD).1 Available data suggest that higher intakes of N-3 fatty acids will reduce various forms of CVD, especially sudden cardiovascular death. These data derive from laboratory animal studies, epidemiological data, metabolic studies, and smaller clinical trials. The literature also contains other evidence that N-3 fatty acids may help to prevent or treat several non-cardiovascular diseases. This editorial nonetheless will limit itself to the cardiovascular system. See p 1852 N-3 polyunsaturated fatty acids are principally of 2 types: (1) a long-chain, 18-carbon atom fatty acid with 3 double bonds (α-linolenic acid), and (2) very long chain polyunsaturated fatty acids of 20 carbon atoms and 5 double bonds (eicosapentaenoic acid [EPA]) and of 22 carbon atoms and 6 double bonds (docosahexaenoic acid [DHA]). α-linolenic acid comes largely from plant oils; the primary sources of EPA and DHA are fish oils. The human body can convert a portion of dietary α-linolenic acid into EPA and DHA. The latter are labeled “essential” fatty acids because they are required for normal development and function of the retina and brain. Most putative health benefits of N-3 fatty are thought to derive from EPA and DHA. Nonetheless, adequate intakes of α-linolenic acid allow for formation of enough EPA and DHA to meet normal requirements. N-3 fatty acids undoubtedly modify biochemical function in many systems.1–7 They enter membrane phospholipids and may alter membrane function there. They decrease the arachidonic acid content of cell membranes, which reduces eicosanoid production. Consequently, N-3 fatty acids can inhibit the synthesis of proinflammatory cytokines, eg, tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), and IL-2; these in turn may destabilize atherosclerotic lesions. Moreover, N-3 fatty acids reduce aggregational properties of blood platelets, thereby …