Meal frequency and coffee intake in colon cancer.

Several studies suggested that frequent eating may increase colon cancer risk. To further clarify this issue, a case-control study was carried out in six areas of Italy on 1,225 incident cases < 75 years of age with histologically confirmed colon cancer and 4,154 control subjects. The controls were hospitalized for acute, nonneoplastic conditions unrelated to long-term dietary modifications. After allowance for education, physical activity, intake of vegetables, and major energy sources, there was a trend of increasing risk with increasing eating frequency (odds ratio for > or = 4 vs. < or = 2 daily meals = 1.24). Coffee intake, which was inversely associated with cancer risk, exerted a modification effect, with an odds ratio of 1.89 for frequent eaters who drank fewer than two cups of coffee per day. Frequent eating increases, whereas high coffee intake decreases, the excretion of bile acids, which are suspected to be carcinogenic to the colon. Thus, it is conceivable that frequent coffee intake may counterbalance the effect of frequent eating.