Beneficial effect of dietary antioxidants on the aging immune system.

Abstract

Aging is associated with depressed immune function. Decline in immunological vigor contributes to many age-associated diseases and the prolonged post-illness recovery often observed in the elderly. Well-documented, age-related functional changes have been defined for both humoral and cell-mediated responses.1 Although all four major cell types of the immune system, i.e., stem cells, macrophages, T-cells and B-cells, show age-related changes, the major alterations have been demonstrated in the T-cell.2 In vivo T-cell-dependent, cell-mediated functions such as primary delayed hypersensitivity, graft vs. host reaction, and resistance to challenge with syngeneic and allogeneic tumors and parasites are depressed with age.3 In vitro, the proliferative response of human and rodent lymphocytes to phyto-hemagglutinin (PHA) and concanavalin A (ConA) as well as natural killer cell activity become depressed with age.4