A case-control study was conducted by interviewing 296 patients with colorectal cancer and 597 controls in Cordoba, Argentina, regarding their dietary habits. With respect to meat consumption, a preference for darkly browned meat surfaces was significantly associated with an increased risk for all cooking procedures (odds ratio = 4.57; 95% CI, 3.10 to 6.73). Increased risk seemed to be related to high cooking temperature and close contact of the food to the heating source, because higher risks were observed for heavily browned surfaces when meats were barbecued or iron-pan cooked.

Comment: Exposure of meat to high cooking temperatures results in the formation of many toxic compounds, including heterocyclic amines, polycyclic aromatic hydrocarbons, cholesterol oxides, lipid peroxides, and advanced glycation end products. Some of these compounds are known carcinogens. Cooking at lower temperatures for longer periods of time results in the formation of less of these compounds than does cooking at higher temperatures for shorter periods of time. If you are a meat-eater, it is probably safest to cook your steak midway between E. coli and heterocyclic amines.

Navarro A, et al. Meat cooking habits and risk of colorectal cancer in Cordoba, Argentina. Nutrition 2004;20:873-877.