Interestingly, eating red or white meat did not increase the risk of rectal cancer in women, whether the meat was cooked rare, medium or well done. And women who consumed red meat drippings had a lower risk.

The scientists concluded that cancer risk comes from substances that are formed when meat is cooked to higher temperatures. Two heat-related compounds, HCAs (carcinogenic heterocylic amines) and PAHs (polycyclic aromatic hydrocarbons) are the main culprits. Eat your meat rare or medium rare, and you may avoid the health risk altogether.

(Journal of Nutrition 134:776-784, April, 2004)

Note: For safety, the USDA recommends cooking hamburgers and ground beef mixtures such as meat loaf to 160 °F. However, whole muscle meats such as steaks and roasts may be cooked to 145 °F (medium rare).