Dietary Polyphenols in Aging: A Systems-Level Perspective on Mitochondrial Quality Control and Microbiome...

Aging is a multifactorial biological process characterized by progressive functional decline and increased susceptibility to chronic diseases. Targeting the molecular mechanisms underlying aging has therefore emerged as an important strategy for promoting healthy aging. Natural polyphenols, widely present in fruits, vegetables, tea, and medical and aromatic plants, have attracted considerable attention due to their geroprotective properties. This review examines current evidence on the ability of major dietary polyphenols, including resveratrol, epigallocatechin gallate (EGCG), curcumin, and quercetin, to modulate the hallmarks of aging, with particular emphasis on mitochondrial quality control as a central regulatory mechanism. Evidence indicates that polyphenols regulate key signaling pathways involved in aging biology, including AMP-activated protein kinase (AMPK), sirtuins (SIRT), mechanistic target of rapamycin (mTOR), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-κB (NF-κB). Through coordinated modulation of these pathways, polyphenols influence mitochondrial biogenesis, mitophagy, redox homeostasis, cellular senescence, and chronic inflammation. In addition, interactions between dietary polyphenols and the gut microbiome generate bioactive metabolites, such as urolithin A, which further contribute to mitochondrial regulation. Overall, polyphenols represent promising modulators of aging-associated pathways and may support strategies aimed at improving healthspan and reducing age-related disease risk.