title: Age-associated changes in immune function: impact of vitamin E intervention and the underlying mechanisms.
abstract: Numerous studies have provided evidence suggesting that aging is associated with significant adverse changes in the immune system, a phenomenon often called immunosenescence, which may be responsible for an observed increase in morbidity and mortality from infectious disease and cancer in the elderly. While a variety of immune cells are known to be affected by aging, declined T cell function is the most striking and best characterized feature of immunosenescence. Both intrinsic changes in T cells and alteration in extrinsic factors are involved. Nutritional intervention has been promoted as a promising approach to delaying/reversing immunosenescence, and vitamin E is one of the best studied candidates in this regard. While vitamin E deficiency is rarely seen, both animal and human studies suggest that intake above currently recommended levels may help restore T cell function which becomes impaired with aging. This effect of vitamin E can be accomplished by directly impacting T cells as well as indirectly, by inhibiting production of prostaglandin E2, a T cell-suppressing lipid mediator known to increase with aging. Vitamin E-induced enhancements of immune functions may have significant clinical implications since vitamin E supplementation has been shown to be associated with both enhanced resistance to influenza infection in aged mice and reduced risk of acquiring upper respiratory infections in elderly human subjects. With a focus on our own work, this paper provides an overview on the beneficial effects of increased vitamin E intake on age-related decline in T cell function, the underlying mechanisms, and its clinical application in reducing the risk of infection.
authors.forename: Dayong
authors.initials: D
authors.lastname: Wu
authors.affiliation: Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA. dayong.wu@tufts.edu.
authors.forename: Simin Nikbin
authors.initials: SN
authors.lastname: Meydani
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D019587:Dietary Supplements; D006801:Humans; D007109:Immunity; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology; D014810:Vitamin E / Q000008:administration & dosage* / Q000502:physiology
chemical_list: D014810:Vitamin E