Antioxidants and cardiovascular diseases: biochemical mechanisms, clinical implications, and nutrition-based strategies

Cardiovascular diseases remain a major global health burden, representing one of the leading causes of mortality and morbidity worldwide. A wide spectrum of conditions—such as coronary artery disease, hypertension, stroke, heart failure, and peripheral vascular disorders—is influenced not only by genetic predisposition, lifestyle behaviors, and environmental factors, but also by disturbances in redox balance. Oxidative stress occurs when the production of reactive oxygen species exceeds the capacity of antioxidant defense mechanisms. This imbalance plays a critical role in the pathogenesis of endothelial dysfunction, inflammatory processes, and atherosclerotic progression. In this regard, antioxidants contribute to cardiovascular protection by limiting oxidative damage and preserving cellular integrity. The detoxification of reactive oxygen species is mediated through complex biochemical pathways involving endogenous antioxidant systems, including enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. In addition, exogenous antioxidants derived from the diet—such as vitamins A, C, and E, selenium, zinc, flavonoids, resveratrol, and lycopene—support these defense mechanisms. These compounds have also been associated with enhanced nitric oxide availability, improved vascular function, attenuation of inflammatory responses, and favorable modulation of lipid metabolism. Although these compounds have been associated with beneficial effects on cardiovascular health, the evidence is not entirely consistent, and some studies have reported non-significant findings. This review aims to evaluate both the biochemical mechanisms and clinical implications of antioxidants in cardiovascular disease, with a particular emphasis on nutrition-based preventive and therapeutic approaches.