Plant polyphenols delay aging: A review of their anti-aging mechanisms and bioavailability

Aging increases the risk of health deterioration, which is a complex process driven by many interconnected mechanisms through multiple signaling pathways, including oxidative stress, inflammation, mitochondrial dysfunction, and intestinal environmental disorders. Plant polyphenols are secondary metabolites found in various plants, including phenolic acids, flavonoids, lignans, stilbenes and other phenolic compounds. These compounds exhibit a range of physiological functions, such as metabolic regulation, cardiovascular protection. Recently, plant polyphenols have gained considerable interest due to their potential to delay aging by suppressing oxidative stress, inhibiting inflammation, and improving mitochondrial function and intestinal environment. However, age-related changes in digestion, absorption, and gut microbiota composition can adversely affect the bioavailability of plant polyphenols, thereby diminishing their therapeutic efficacy. This article reviews the significant role of plant polyphenols in delaying the aging process and explores the underlying mechanisms involved. It also presents the current research status on the bioavailability of plant polyphenols and emphasizes that age-related gastrointestinal changes, such as decreased enzyme activity, altered gastrointestinal motility and imbalances in the gut microbiota, are key factors influencing polyphenol bioavailability in the elderly, encouraging to carry out research on the bioavailability of plant polyphenols in the elderly in the hope of developing novel anti-aging strategies.