The role of the antioxidant vitamin supplementation in the prevention of cardiovascular diseases

Abstract

Industrial and technological revolutions have resulted in dramatic shifts in the diseases that are responsible for illness and death. In particular, cardiovascular disease (CVD) has emerged as the dominant chronic disease in many parts of the world. Diet, tobacco smoking, physical inactivity, obesity, lipid levels, hypertension and diabetes mellitus have contributed to their wide diffusion. Oxidative damage and the production of free radicals in the endothelium are two of the main factors involved in the pathogenesis of the atherosclerotic process that causes CVD. One of the more important results of basic research on dietetic regimes has shown that people who consume large amounts of fruits and vegetables have a lower incidence of CVD, stroke and tumours, but the specific mechanisms of these foods (which have an apparently protective effect) are still not completely clear. Possible reasons could include a greater consumption of fruit and vegetables, and an increased consumption of dietetic fibres. Recently, it been proposed that micronourishments with an antioxidant activity could be responsible for the reduction of chronic diseases. Research supplies a hypothetical mechanism by which antioxidant substances may be reducing the risk of atherosclerosis through the inhibition of oxidative damage. Appropriate nutritional practices are of central importance in managing risk and treatment of CVD; in fact, many current guidelines for a healthy general population contain nutritional recommendations to reduce the risk of these diseases. A large number of descriptive and case-control studies suggests that the consumption of many antioxidant vitamins (A, C and E) reduces the risk of CVD. Such data raises the following problem of whether supplementation of vitamins A, C and E emerges as being useful in the primary prevention of CVD. Many important studies involving a great number of participants have not confirmed this hypothesis and the results are often contradictory. This review examines the studies published in the literature that document the effect of supplementation with antioxidant vitamins (A, C and E) in the primary and secondary prevention of CVD due to an atherosclerosis process.