A central role of heme iron in colon carcinogenesis associated with red meat intake.

Heme iron may contribute positively to development of colon cancer associated with red meat consumption.

This study was carried out to determine the role and mechanisms used by heme iron in the promotion of colon cancer associated with red meat consumption. Researchers administered nutritional doses of heme iron (hemoglobin diet), heterocyclic amines, and endogenous N-nitroso compounds (NOC) to rats and mice. The genotoxicity and cytotoxicity were evaluated in normal and Apc-deficient cell lines in the colon mucosa of the rats and mice.

Researchers observed increased tumor loads and preneoplastic lesions in rats and mice given heme iron. On the other hand, NOC and heterocyclic amines had no carcinogenic effect on rats in this study. Genotoxicity and cytotoxicity were observed in normal cells of the colon mucosa of rats and mice placed on hemoglobin diets. This study suggested that the carcinogenic effect of heme iron is mediated through lipid peroxidation. These results strongly linked red meat consumption and heme iron with the development and proliferation of cancerous cells in the colon.