The role of vitamin E in atherosclerosis.
Epidemiological and biochemical studies infer that oxidative processes, including the oxidation of low-density lipoprotein (LDL), are involved in atherosclerosis. Vitamin E has been the focus of several large supplemental studies of cardiovascular disease, yet its potential to attenuate or even prevent atherosclerosis has not been realised. The scientific rationale for vitamin E supplements protecting against atherosclerosis is based primarily on the oxidation theory of atherosclerosis, the assumption that vitamin E becomes depleted as disease progresses, and the expectation that vitamin E prevents the oxidation of LDL in vivo and atherogenic events linked to such oxidation. However, it is increasingly clear that the balance between vitamin E and other antioxidants may be crucial for in vivo antioxidant protection, that vitamin E is only minimally oxidised and not deficient in atherosclerotic lesions, and that vitamin E is not effective against two-electron oxidants that are increasingly implicated in both early and later stages of the disease. It also remains unclear as to whether oxidation plays a bystander or a casual role in atherosclerosis. This lack of knowledge may explain the ambivalence of vitamin E and other antioxidant supplementation in atherosclerosis.
Upston
Joanne M
JM
Centre for Vascular Research, School of Medical Sciences, University of New South Wales, UNSW Sydney, NSW 2052, Australia.
Kritharides
Leonard
L
Stocker
Roland
R
D000818:Animals; D000975:Antioxidants / Q000502:physiology / Q000627:therapeutic use*; D001161:Arteriosclerosis / Q000378:metabolism / Q000517:prevention & control*; D004195:Disease Models, Animal; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D010084:Oxidation-Reduction; D014810:Vitamin E / Q000502:physiology / Q000627:therapeutic use*
D000975:Antioxidants; D008077:Lipoproteins, LDL; D014810:Vitamin E