*6.1.1 Mechanism*

A proposed mechanism for the protective properties of calcium against CRC is its ability to bind to unconjugated bile acids and free fatty acids (FFAs), thereby limiting their toxic effects on the colorectum [4, 61]. Cell culture studies suggest that it may also suppress cell proliferation and promote cell differentiation and

apoptosis, likely by influencing different cell-signaling pathways [4, 62]. Calcium may also prevent colonic K-ras mutations and inhibit haem-induced promotion of colon carcinogenesis [63, 64]. In addition, calcium also inhibits oxidative DNA damage and modulates CRC-related cell-signaling pathways [4].
