Therapeutic potential of vitamin E in heart disease

Low density lipoprotein (LDL) oxidation is considered an important step in the atherogenic process. Oxidatively modified particles induce the expression of adhesion molecules, stimulate the production of inflammatory cytokines and impair endothelial function. The measurement of oxidised LDLs in vivo is very difficult, therefore most investigators rely on the measurement of in vitro oxidability of these particles to evaluate their deleterious effects. Supplementation with water and lipid soluble anti-oxidant vitamins, especially vitamin C and E, significantly increase the resistance to LDL oxidation. Vitamin E supplementation also improves endothelium-dependent vasodilation in hypercholesterolaemic and subjects who smoke cigarettes. Epidemiological studies have not consistently demonstrated a protective effect of vitamin E consumption as food or supplements on coronary events or stroke. Likewise, only one of five large prospective trials has shown a beneficial effect of vitamin E supplementation on cardiovascular events or mortality. One report showed that supplemented haemodialysed patients had a lower incidence of cardiovascular events. Thus, presently, there is not enough evidence to widely recommend the use of vitamin E supplements for vascular protection.