Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved

Nadia Bastide (1) , Fabrice H.F. Pierre (1) , Denis E. Corpet (1)

1 Xénobiotiques

Red meat and processed meat intake is associated with a risk of colorectal cancer, a major cause of death in affluent countries. Epidemiological and experimental evidence supports the hypothesis that heme iron present in meat promotes colorectal cancer. This meta-analysis of prospective cohort studies of colon cancer reporting heme intake included 566,607 individuals and 4,734 cases of colon cancer. The summary relative risk of colon cancer was 1.18 [95%C.I.: 1.06-1.32] for subjects in the highest category of heme iron intake compared with those in the lowest category. Epidemiological data thus show a suggestive association between dietary heme and risk of colon cancer. The analysis of experimental studies in rats with chemically-induced colon cancer showed that dietary hemoglobin and red meat consistently promote aberrant crypt foci, a putative pre-cancer lesion. The mechanism is not known, but heme iron has a catalytic effect on (i) the endogenous formation of carcinogenic N-nitroso compounds and (ii) the formation of cytotoxic and genotoxic aldehydes by lipoperoxidation. A review of evidence supporting these hypotheses suggests that both pathways are involved in heme iron toxicity.

Mots clés: Review; Meta-Analysis; Colorectal cancer; Red and Processed meat; Heme iron; Apparent Total N-nitroso Compounds; Lipid peroxidation; ATNC; NOC; 4-HNE

Domaines: Cancer

Nadia Bastide, Fabrice H.F. Pierre, Denis E. Corpet. Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved. Cancer Prevention Research, 2011, 4 (2), pp.1-16. ⟨10.1158/1940-6207.CAPR-10-0113⟩. ⟨hal-00543808⟩