Calcium, dairy products, and colorectal cancer.

The relation between calcium intake, estimated from frequency of use of 29 food items, and colorectal cancer risk was analyzed using data from a case-control study conducted in Northern Italy. The study was conducted on 558 cases of colon cancer, 352 cases of rectal cancer, and 1,032 controls admitted to the hospital for acute, nonneoplastic, nondigestive tract disorders (39% with traumas, 17% nontraumatic orthopedic diseases, 25% acute surgical conditions, 19% other miscellaneous disorders). There was no appreciable trend in risk of colon or rectal cancer in relation to measures of calcium intake. The multivariate relative risk (adjusted for age, sex, education, area of residence, and consumption of selected indicator foods) for highest versus lowest quintile was 1.1 for colon and 1.0 for rectum. Likewise, there was no appreciable difference between cases and controls with reference to frequency of consumption of the two major calcium-containing foods (milk and cheese), with relative risk for the highest level of intake between 0.9 and 1.2. This study indicates that little or no protection on large bowel cancer risk is provided by dairy products or calcium intake in a range of 0.5-1.5 g per day.