Vitamins and minerals with antioxidant properties and cardiometabolic risk: controversies and perspectives

Oxygen reactive species (ROS) are generated during cellular processes. In excess, they may cause damages to the cell. Oxidative stress is animbalance in the redox state that favors oxidation. Endogenous enzymes and some vitamins and minerals participate in the plasma antioxidant defense. Vitamin E is found in the plasma and in the LDL particle, avoiding lipid peroxidation. Observational studies reported an inverse association between vitamin E consumption and cardiometabolic (CM) risk. However, clinical trials were not able to prove the efficacy of its supplementation on CM endpoints. Vitamin C participates in the vitamin E regeneration system, keeping the plasma's antioxidant potential. Data about beneficial effects of its supplementation in CM risk reduction are inconclusive. The antioxidant activity of carotenoids is partially responsible for its protective role against cardiovascular diseases Supplementation of this nutrient did not provide consistent findings in terms of CM risk and cancer. reduction. Recently, zinc and selenium's participation in the antioxidant defense has been studied, yet its supplementation in individuals with normal levels and adequate ingestion of these nutrients does not seem necessary. In summary, the role of these micronutrients for CM risk is still very controversial. Epidemiological studies suggest that diets rich in antioxidants, or simply in fruit and vegetables intake, can reduce CM risk. Further studies are needed before recommending antioxidant supplements for this purpose. Arq Bras Endocrinol Metab. 2009;53(5):550-9.