DIETARY-INTAKE OF SPECIFIC CAROTENOIDS AND VITAMIN-A, VITAMIN-C, AND VITAMIN-E, AND PREVALENCE OF COLORECTAL ADENOMAS

We determined whether intakes of the main dietary carotenoids (alpha-c arotene, beta-carotene, beta-cryptoxanthin, lutein plus zeaxanthin, an d lycopene) and of vitamins A, C, and E were associated with the preva lence of colorectal adenomas among male and female members of a prepai d health plan in Los Angeles who underwent sigmoidoscopy (n = 488 matc hed pairs). Participants, ages 50-74 years, completed a 126-item semiq uantitative food-frequency questionnaire and a nondietary questionnair e from 1991 to 1993. In the univariate-matched analysis, alpha-caroten e, beta-carotene (with and without supplements), beta-cryptoxanthin, l utein plus zeaxanthin, vitamin A (with and without supplements), and v itamin C (with and without supplements) were associated with a decreas ed prevalence of colorectal adenomas. After adjustment for intake of c alories, saturated fat, folate, fiber, and alcohol, and for current sm oking status, body mass index, race, physical activity, and use of non steroidal anti-inflammatory drugs, only beta-carotene including supple ments was inversely associated with adenomas [odds ratio (OR), 0.6; 95 % confidence interval (CI), 0.4-1.1; trend, P = 0.04; ORs compare high est to lowest quartiles]; vitamin C showed a weaker inverse associatio n (OR, 0.8; 95% CI, 0.5-1.5; trend, P = 0.08); and the remaining compo unds were no longer clearly associated with risk. After including beta -carotene with supplements and vitamin C simultaneously in the multiva riate model, the association of beta-carotene with supplements with ad enomas was weakened (OR, 0.8; 95% CI, 0.5-1.3; trend P = 0.15), and vi tamin C was no longer associated with risk. These data provide only mo dest support for a protective association of beta-carotene with colore ctal adenomatous polyps.