Modulation of Redox Balance by Phytochemicals: Implications for Cardiovascular Health

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide, with oxidative stress playing a major role in disease pathogenesis by promoting endothelial dysfunction, vascular inflammation, and tissue damage. Oxidative stress results from an imbalance between antioxidant defenses and reactive oxygen species (ROS) in favor of ROS. Excessive ROS damage macromolecules and may trigger a chain reaction of lipid peroxidation, protein modification, and DNA damage. Phytochemicals are naturally occurring compounds in fruits and vegetables that may modulate redox homeostasis and positively impact cardiovascular health. The flavonoid Quercetin, Resveratrol, Curcuminoids, Coenzyme Q10, Hydroxysafflor yellow A, and Vitamins C and E have shown promise in human studies for improving endothelial function, lipid profile and markers of oxidative stress and inflammation. Among the key mechanisms of protection are their antioxidant role, anti-inflammatory role or modulation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, all of which contribute to cardiovascular protection. However, there are challenges associated with their use for health, such as the complexity of their quality and quantity, which require standardization, as well as their mechanisms of effects. Moreover, their systemic availability and bioactivity largely depend on metabolic transformation by the host gut microbiota. This review analyzed relevant publications in PubMed, Scopus, and Web of Science, up to February 2026, and summarizes current knowledge on phyto–chemical-mediated modulation of oxidative stress and its implications for cardiovascular protection in humans. The evidence suggests that phytochemicals hold promise for CVD prevention and treatment, but more work is needed to achieve standardization in quality and quantity.