Nutraceuticals Against the Silent Killers: Role of Secondary Metabolites in the Prevention and Management of Hypertension and Hyperlipidemia

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide, with hypertension and hyperlipidemia often termed “silent killers” being major modifiable risk factors. This review evaluates the antihypertensive and antihyperlipidemic potential of three dietary secondary metabolites: epigallocatechin-3-gallate (EGCG) from green tea, quercetin from onions, and anthocyanins from berries. Quercetin, incorporated in salads through onion consumption, shows dose-dependent blood pressure (BP) reductions (2.9–8.8 mmHg) and modest low-density lipoprotein cholesterol (LDL-C) lowering (3–8%), primarily via angiotensin-converting enzyme inhibition and modulating the SCAP–SREBP2–LDLr pathway. EGCG, commonly consumed as a breakfast beverage, demonstrates modest but consistent reductions in systolic, diastolic BP (2.8–7 mmHg and 1.2–4 mmHg, respectively) and LDL-C (3–10%), mediated through endothelial nitric oxide synthase activation, endothelin-1 suppression, and improvement in lipid metabolism. Anthocyanins, delivered through berry-based juices, yield substantial systolic and diastolic reductions (6–12 mmHg and 2.5–6 mmHg, respectively) and significant improvements in LDL-C and high-density lipoprotein cholesterol via enhancing nitric oxide production, inhibition of cholesteryl ester transfer protein, and promoting cholesterol efflux. Beyond their physiological benefits, these nutraceuticals represent economically viable interventions, as they can be sourced from affordable, widely available foods, potentially reducing healthcare costs associated with CVD management. Collectively, evidence from clinical trials suggests that integrating these compounds into daily diets may offer a synergistic, safe, cost-effective strategy for managing hypertension and hyperlipidemia. However, heterogeneity in study designs, dosages, and populations underscores the need for standardized long-term trials to validate efficacy and optimize dietary recommendations.