Dairy foods and prevention of colon cancer: human studies

摘要

A review. Recent approaches to lowering the incidence of colon cancer have included attempts at dietary prevention and chemoprevention. In colon cancer there is a inverse relationship with dietary calcium and/or vitamin D intake. Supplemental calcium administration will change proliferative indices of risk for colon cancer from high to lower risk patterns. The principal current hypothesis for the action of calcium implies that calcium may precipitate or bring out of solution fatty acids and bile acids that are potentially toxic to the colorectal epithelium. Both calcium administration and dietary food administration are associated with lowering of cytotoxicity in studies in vitro. There is biochemical and biological evidence in cell culture systems that exposure to calcium and/or vitamin D reduces the oncogenic properties of colon cancer cells. A recent blinded study of the administration of low-fat dietary foods demonstrated a significant improvement in several parameters of proliferation as well as in two differentiation markers from a high to a lower risk pattern. Furthermore, administration of calcium also has been shown to reduce the incidence of recurrent adenomatous polyps in individuals at increased risk for colon polyp formation becauseof the presence of prior colon adenomatous. These combined data suggest that administration of supplemental calcium or low-fat dairy foods may have a significant effect upon colonic polyp and perhaps colon cancer incidence.