DIETARY HABITS AND COLORECTAL-CANCER IN A LOW-RISK AREA - RESULTS FROM A POPULATION-BASED CASE-CONTROL STUDY IN SOUTHERN ITALY

Many epidemiological studies have focused on the relationships between diet and colorectal cancer, but only a few have been conducted in the Mediterranean area. A population-based case-control study was carried out from July 1987 to June 1989 in a low-risk area in Southern Italy. By means of an ''ad hoc'' tumor registry, 132 diagnosed colorectal ca ncers were detected during the two years of study. One hundred ninetee n of these 132 colorectal cancer cases were interviewed about their pe rsonal dietary habits with use of a questionnaire concerning the frequ ency of consumption of 70 foods or beverages. An equal number of contr ols was randomly selected from the lists of general practitioners of t he area during the same period and interviewed with the same food freq uency questionnaire. In a multivariate analysis, the relative risks (R Rs) of developing colorectal cancer were estimated according to the di fferent levels of consumption of food groups and selected food items. All RRs were adjusted for age, sex, education, smoking status, and mod ifications in diet in the previous 10 years. The risk of colorectal ca ncer increased nearly threefold for the highest level of consumption o f foods with a high content of refined sugar [RR = 2.75, 95% confidenc e interval (CI) 1.26-5.97] and for the consumption of wine (>1 1/day) (RR = 3.22, 95% CI 1.05-9.88). An inverse relationship was revealed fo r the highest consumption of raw and cooked vegetables (RR = 0.51, 95% CI 0.25-1.04) and diary products (RR = 0.46, 95% CI 0.22-0.98) and fo r the consumption of more than two cups of coffee per day (RR = 0.38, 95% CI 0.16-0.89). In this Mediterranean area, the main source of calo ries, cereals, did not show a significant relationship with colorectal cancer. These findings support the hypothesis that the local Mediterr anean dietary pattern could explain the low risk of colorectal cancer.