The role of cooked food mutagens as possible etiological agents in human cancer. A critical appraisal of recent epidemiological investigations.

The paper reviews the epidemiological studies that investigate the relationships between dietary protein intake and the risk of some cancer and that have been published since 1980. A comparison of these reports is complicated because of many confounding factors that could obscure the conclusions (e.g. choice of controls) and because it is difficult to distinguish the consumption of fat from that of animal proteins. The 75 examined publications deal with the influence of food intake on different cancers: colo-rectal (42), stomach (8), breast (7), ovarian (4), endometrium (3), prostate (4), pancreas (2), urothelium (1), bladder (2), brain (1), lymphoma (1). From these studies in parallel with information from other sources, it is concluded that pyrolysis products generated by heat treatment of protein-rich food could be responsible factors for, at least, colo-rectal cancer.