ABSTRACT

This chapter examines the protective effect of dietary calcium on azoxymethane-induced intestinal carcinogenesis. A study involving approximately 2,000 people for almost 2 decades confirmed the hypothesis, as it showed an inverse correlation between dietary calcium and colon cancer. Dietary calcium has been shown to lower the epithelial cell proliferation rate in the intestinal tissue of experimental animals upon intrarectal administration of bile acids and also free fatty acids. Mineral and vitamin content were adjusted to compensate for the lower consumption of high-fat diets. Tumor incidence as measured by total neoplastic lesions significantly decreased in the animals fed the high-fat diets containing calcium at the 300% National Research Council (NRC) calcium level compared with the 50% NRC calcium groups. The results indicate that a diet high in calcium provides a protective effect against Azoxymethane-induced tumorigenesis in rats fed high-fat diets. Data also indicate that as dietary calcium increases, both total fecal steroid excretion and bile acid excretion increase.