OXIDIZED LOW-DENSITY LIPOPROTEINS IN ATHEROGENESIS - ROLE OF DIETARY MODIFICATION

The development of atherosclerosis is a complex and multistep process. There are many determinants in the pathogenesis of this condition, wi th different factors presumably playing key roles at different times i n the evolution of the atherosclerotic plaque. It has been suggested t hat oxidation of low density lipoproteins (LDL) by cells in the artery wall leads to a proatherogenic particle that may help initiate early lesion formation. For this reason, understanding the determinants of L DL susceptibility to oxidation is essential for developing therapeutic strategies to inhibit this process. Oxidation of LDL begins with the abstraction of hydrogen from polyunsaturated fatty acids; thus, LDL fa tty acid composition undoubtedly contributes to the process of LDL oxi dation. Since dietary fatty acids influence the fatty acid composition of LDL and cell membranes, the amount and type of fat in the diet may effect susceptibility of LDL and cells to oxidative damage. Additiona lly, since cell membrane fatty acid composition also influences cellul ar formation of reactive oxygen species, dietary fatty acids may help determine the prooxidant activity of artery wall cells. Both cells and lipoproteins contain a variety of antioxidants that provide protectio n against oxidative stress. A major source of these antioxidants is th e diet. Enrichment of the diet with foods high in such antioxidants as vitamin E, beta-carotene, or vitamin C, or supplementation of the die t with antioxidant vitamins, may inhibit oxidation and the process of atherosclerosis.