Differences and trends in antioxidant dietary intake in smokers and non-smokers, 1980-1992: The Minnesota Heart Survey

PURPOSE: Differences and secular trends in dietary antioxidant vitamin inta ke (vitamins E, C, and beta-carotene) in current non-smokers; light smokers , and heavy smokers were examined as part of the Minnesota Heart Survey. METHODS: Three cross-sectional surveys were conducted in adults ages 25-74 years in 1980-82 (N = 1682), 1985-87 (N = 2326), and 1990-92 (N = 2487). Di etary information-was obtained from a 24-hour dietary recall. Smoking was a ssessed through self-report. Intakes were adjusted for age, energy intake, body mass index, education level, and exercise level (vitamins E, C and bet a-carotene) RESULTS: Antioxidant vitamin intakes were significantly higher in non-smoke rs than in light (1-20 cig/day) and heavy smokers (>20 cig/day) when all th ree survey periods were combined. In men, mean vitamin E intake was 9.2 mg, 8.6 mg, and 7.8 mg for non-smokers, light smokers, and heavy smokers, resp ectively. Results were similar in men for beta-carotene (non-smokers 1408 m u g, light smokers 1287 mu g, and heavy smokers 1064 mu g), and vitamin C ( non-smokers 81 mg, light smokers 67 mg, and heavy smokers 56 mg). Women had results of similar magnitude and direction. From 1980-92, secular trends i n men showed non-significant increases from 1980-82 to 1990-92 in p-caroten e (+6.1%), while decreases were observed in vitamins E (-1.1%) and C (-2.6% ). In contrast, women had large decreases in all antioxidant vitamin intake s: vitamin E (-13%), vitamin C (-18.6%), and beta-carotene (-16.2%). CONCLUSIONS: Light and heavy smokers had a significantly lower overall mean dietary antioxidant vitamin intake than non-smokers. Over the decade, anti oxidant dietary intake remained relatively stable in men and decreased in w omen in Minneapolis-St. Paul, despite improvements in access to antioxidant rich fruits and vegetables. Ann Epidemiol 2000;10:417-423. (C) 2000 Elsevi er Science Inc. All rights reserved.