Nutrient dietary patterns and the risk of colorectal cancer: a case-control study from Italy

The role of diet on colorectal cancer has been considered in terms of single foods and nutrients, but less frequently in terms of dietary patterns. Data were derived from an Italian case-control study, including 1,225 subjects with cancer of the colon, 728 subjects with rectal cancer, and 4,154 hospital controls. We identified dietary patterns on a selected set of nutrients through principal component factor analysis. Odds ratios (OR) and 95% confidence intervals for both cancers were estimated using unconditional multiple logistic regression. We identified 5 major dietary patterns. Direct associations were observed between the Starch-rich pattern and both cancer of the colon (OR = 1.68) and of the rectum (OR = 1.74). Inverse relationships were found between the Vitamins and fiber pattern and rectal cancer (OR = 0.61), between the Unsaturated fats (animal source) and the Unsaturated fats (vegetable source) and cancer of the colon (OR = 0.80 and OR = 0.79, respectively). No other significant association was found. The Starch-rich pattern is potentially an unfavorable indicator of risk for both colon and rectal cancer, whereas the Vitamins and fiber pattern is associated with a reduced risk of rectal cancer and the Unsaturated fats patterns with a reduced risk of colon cancer.