Dietary fiber and colon cancer: animal model studies.

Support for a protective role for certain dietary fibers in the etiology of colon cancer has come from nutritional epidemiologic studies. Recommendations to increase consumption of fiber-containing food and decrease the intake of dietary fat should form the basis of a diet that is unlikely to do harm, and may have the potential for reducing the development of colon cancer, in humans. Studies examining the role of dietary fiber as an inhibitor of colon cancer in animal models appear to have provided some conflicting results, due mostly to differences in the nature and amount of carcinogen used to induce colon tumors, variation in the composition of the experimental diets, and relative difference in food intake by animals, to cite a few of the methodological problems. However, overall, the feeding of wheat bran appears to inhibit color tumor development to a greater degree than do other dietary sources of fiber.