[Vitamin E and cardiovascular prevention].
The antioxidant properties of vitamin E are well established. In humans, they appear very clearly from the nutritional supplementation trials. There is a strong correlation between supplied doses (>= 50 mg/j), vitamin E content of LDL and antioxidant protection of LDL. The consumption studies mostly suggest that the cardiovascular disease risk is diminished by the vitamin E supplementation, this being not true for vitamin E supplied by food strictly. In spite of the fact that there is a coherence between these results due in particular to the highly atherogenic role of oxidized low density lipoprotein, it is not allowed to claim that only the increased protection of LDL against oxidation is responsible for the diminished risk. The cell-regulating properties of vitamin E that have been more recently discovered have also to be taken into account as regards the functions of platelets, monocytes-macrophages, endothelial cells and vascular smooth muscle cells. The LDL-vitamin E capacity at decreasing the superoxide anion production (involved in turn in the oxidation process of LDL) could also play a role in preventing cardiovascular risk. The nutritional intervention studies undertaken in secondary prevention indicate a beneficial effect in terms of cardiovascular morbidity, either for low dose (50 mg), or for higher dose (>= 270 mg/d) intake, but without effect in terms of mortality. A recent study presumably supports a beneficial effect at the dose intake of 300 mg/d only in terms of cardiovascular mortality. Only one intervention has been carried out in condition of primary prevention, leading to the absence of effect at the dose employed (50 mg/d). The studies on the mechanisms of action make plausible the beneficial effects observed in analytical or experimental epidemiology. However, the experimental epidemiology does not provide indisputable evidence for the efficacy of the secondary prevention of cardiovascular risk by vitamin E supplementation. There is no intervention study using doses higher than 50 mg/d in primary prevention. There is a need for such studies in the not too distant future. A period of several years will be necessary before having new data possibly resulting in a consensus achievement.
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Directeur de recherche INRA, UMI, Faculté de médecine de Montpellier, France.
D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood / Q000401:mortality / Q000517:prevention & control*; D002986:Clinical Trials as Topic; D004032:Diet; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011322:Primary Prevention; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014810:Vitamin E / Q000008:administration & dosage / Q000502:physiology / Q000627:therapeutic use*; D019207:beta Carotene / Q000008:administration & dosage / Q000627:therapeutic use
D008077:Lipoproteins, LDL; D019207:beta Carotene; D014810:Vitamin E