Curcumin and metabolic syndrome: Mechanistic and clinical evidence for modulating diabetes and cardiovascular risk factors

Metabolic Syndrome (MetS) is characterized by central obesity, hyperglycemia, dyslipidemia, and elevated blood pressure. Obesity contributes to low-grade inflammation, oxidative stress, metabolic endotoxemia, decreased adiponectin, and increased leptin, which play major roles in insulin resistance. Inflammation and insulin resistance enhance fatty acid release from adipose tissue, increasing hepatic uptake, VLDL production, and hypertriglyceridemia. Elevated VLDL further promotes triglyceride-HDL exchange via CETP, lowering HDL levels. Oxidative stress, increased angiotensin II production in adipose tissue, and upregulated receptor expression are also key factors in hypertension associated with MetS. Curcumin, a natural polyphenolic compound, has been shown to modulate many of these processes. Experimental evidence suggests that curcumin can reduce inflammation and oxidative stress, regulate adipokines, improve lipid metabolism, and support vascular health. Several clinical trials have also reported beneficial effects of curcumin supplementation on the components of MetS. In this review, we first summarize the main mechanisms underlying MetS and then discuss in detail the molecular and physiological effects of curcumin on these pathways. Finally, we provide an overview of clinical findings on curcumin and its potential as a supportive strategy in improving MetS.