[Effect of free radicals and antioxidant on the vascular wall]

Free radicals pay an important role in the pathogenesis of atherosclerosis by their direct toxic action on the vascular endothelium as well as by antioxidant of low density lipoproteins (LDL) which subsequently increase their atherogenic potential. Natural antioxidants interrupt the chain-like increase of radicals and thus also the risk of oxidation stress. The majority of epidemiological data indicate that an increased intake of fruit, vegetables and other foods of plant origin reduces the risk of cardiovascular disease. On the other hand, several so far not completed long-term intervention studies with some antioxidant vitamins (e. g. vitamin E, beta-carotene) don't provide such unequivocal results. This indicated that fruit and vegetables contain other protective substances, other than vitamins, some which were identified so far. It is beyond doubt than even the intake of very large amounts of antioxidant vitamins does not ensure in humans exposed to the potent action of several traditional cardiovascular risk factors (hypertension, high LDL-cholesterol, smoking) unequivocal protection against ischaemic heart disease. On the other hand, it is probable that chronic antioxidant deficiency enhances the risk of development of pathological changes of the vascular system. So far the problem has yet been resolved whether to recommend within the framework of cardiovascular disease prevention to the public at large daily consumption of preparations containing natural antioxidants. The final word on the effectiveness of antioxidants in the prevention of cardiovascular disease will be provided by extensive intervention studies which are at present under way, the results of which will be available within the few years.