Polymorphism in manganese superoxide dismutase, antioxidant intake and all-cause, cancer and cardiovascular disease mortality

Background. Exogenous oxidants and bodily processes produce endogenous oxidants, or free radicals, that can damage DNA, membranes and other body constituents, and may ultimately lead to cancer, cardiovascular disease, aging and premature death. Exogenous and endogenous antioxidants can react with free radicals to convert these oxidants to less harmful substances and thus, may protect against certain diseases. To understand the independent and joint relations of exogenous (C47T polymorphism in manganese superoxide dismutase) and endogenous antioxidants (dietary intake of fruits and vegetables, vitamin C, vitamin E and beta-carotene) with all-cause, cancer and cardiovascular disease mortality, a prospective cohort study was conducted among participants of the Washington County, MD CLUE I and II studies.; Methods. Included were men and women participants of the CLUE studies who donated a blood sample in both 1974 and 1989 and completed the modified Block food frequency questionnaire in 1989 (N = 6,151). The FFQ estimated nutrients and food intake over the past year. The C47T genotypes (CC, CT, TT) were determined by the Taqman® fluorogenic method for nucleic acid analysis (PE Corporation, Foster City, CA). Individuals were followed from 1989 to time of death or January 2002.; Results. Overall, higher intake of fruits and vegetables was associated with a lower risk of all-cause, cancer and cardiovascular mortality. No consistent associations were observed with antioxidant nutrients (Vitamin C, E, and beta-carotene) and all-cause, cancer and cardiovascular disease mortality. The C47T MnSOD polymorphism was not associated with all-cause, cancer and cardiovascular mortality. The relation between C47T MnSOD polymorphism and all-cause, cancer and cardiovascular disease mortality was not modified by exposure to oxidants (smoking) or antioxidants (fruit and vegetable intake).; Conclusions. These findings support the general health recommendations to consume several fruits and vegetable servings daily.