Plant polyphenols in healthcare and aging

Abstract

Aging is characterized by a progressive inability of organs of biological systems to defend against environmental stressors. Oxidative stress, a state of imbalance between cellular production of oxygen free radicals and reactive oxygen species (ROS) and their removal by antioxidants, has emerged as a critical player in aging process. Indeed, oxidative stress status is observed during aging and in numerous age-related diseases. The accumulation of deleterious oxidative damages occurring in cells with advancing age would induce damage of the vital cellular macromolecules, lipids, proteins, and DNA, which can potentially lead to cell dysfunction and death. Hence, organs and tissues accumulate free radical damage over time under conditions in which their endogenous antioxidant defenses are overwhelmed, resulting in overall cellular redox imbalance and impaired organ physiology. Dietary antioxidants are bioactive molecules, which can scavenge ROS and decrease the incidence of oxidative stress-induced damage. Plant antioxidants, including polyphenols, have been extensively studied for their beneficial health effects in human. There is evidence that populations consuming diets rich in polyphenols are less susceptible to oxidative damage and diseases during aging. The present chapter deals with the free radical theory of aging, providing current evidence of dietary interventions aimed at limiting the aging process. This chapter also describes the biological activities of some abundantly occurring polyphenols and their possible roles in healthcare as well as in prevention and treatment of age-related diseases.