Antioxidant Vitamins and Atherosclerosis

Abstract

Oxidative modification of low-density lipoproteins (LDL) plays an important role in atherogensis. Oxidized LDL can be formed in vitro by smooth muscle cells, endothelial cells and monocyte-derived cells, all of which are found in the arterial wall. Human and animal atherosclerotic leasions have been found to contain oxidized LDL. It is thought that oxidized LDL particles are ligands for the ‘scavanger’ receptors on macrophages and can therefore converted to the cholesterol-loaded foam cells characteristic of the early atherosclerotic leasions, the fatty streak. In recent years, the use of nutritional antioxidants, including vitamins E and C, carotenes, and selenium, in the prevention of atherosclerosis has gained heightened interest. Many in vitro experiments and studies in animals have shown that the antioxidant protect cells from oxidative destruction. Epidemiological studies provide evidence supporting the results from these in vitro and animal studies. The potential anti-antherogenic value of the antioxidant vitamins is further indicated by the inverse relationship between plasma levels of vitamins C and E and carotene, and the risk of coronary heart disease. The scope of this review is to present evidence supporting the use of vitamin antioxidants in the prevention of atherosclerosis, including their mechanisms of action, synergistic effects, and future research merited in this controversial field of study.