A case-control study of colorectal adenomatous polyps and consumption of foods containing partially hydrogenated oils

The trans fatty acids produced by partially hydrogenating vegetable oils ma y cause colorectal neoplasia by interfering with cell membrane function or eicosanoid synthesis. This possibility provides a rationale for looking at the relation between colorectal adenomatous polyps and consumption of foods containing partially hydrogenated vegetable oils (PHVOs), A total of 516 c ases and 551 controls who underwent screening sigmoidoscopy from 1991-1993 were recruited from a prepaid Los Angeles health plan. Subjects were interv iewed and given a self-administered food frequency questionnaire. Food item s containing PHVOs were divided into four groups characterized by principal ingredients and preparation methods: sweetened baked goods, candy bars, oi ls and condiments, and french fries and chips. After adjusting for age, sex , physical activity, body mass index, smoking, total energy, and red meat a nd vegetable intake, there was a positive association between polyps and sw eetened baked goods [350+ versus <50 kcal/day (odds ratio, 2.1; 95% confide nce interval, 1.3-3.5)]. No association was found with the other food group s after adjustment for dietary and nondietary covariates, Neither was total dietary trans fatty acid associated with adenomas after adjustment for swe etened baked goods and other covariates, These results do not support the h ypothesis that eating foods containing PHVOs increases the risk of colorect al adenomas, but they are consistent with the hypothesis that foods high in fat and sugar and low in fiber and correlated micronutrients increase the risk of adenomas.