The fat/fiber antagonism in experimental colon carcinogenesis

Current epidemiologic and experimental data emphasize the importance of nutrition in colon carcinogenesis. The interactions between dietary fat and dietary fiber were studied in the dimethylhydrazine model for colon cancer. A strict pair-feeding system was developed, and rats were fed one of five semisynthetic diets containing various amounts and types of fat and fiber. The incidence and number of tumors per animal were increased in all fat-fed groups. Adding fiber to the diets provided either partial (polyunsaturated fat) or complete (saturated fat) protection against the deleterious effect of fat. The antagonism between fat and fiber and the clinical relevance of these data are discussed.