The connection between meat—especially red meat and processed meat—and colon cancer has been well studied. But the connection between meat and rectal cancer is less well understood. Researchers looked for a connection in cancer registries from Utah and Northern California.

What the researchers wanted to know: Does eating meat increase your risk of rectal cancer?

What they did: The researchers found 952 people with rectal cancer and matched them with 1,205 controls, people without cancer, who were the same sex, and roughly the same age. The cancer cases came from cancer registries; the controls were from Kaiser Permanente membership lists, driver's license lists, or Social Security lists. Then interviewers went out and asked each person about their diets. For the two years before their diagnosis, patients were asked what they'd eaten, how often, serving size, and whether fat was added. Interviewers asked for details about how meat was prepared; from that, researchers estimated how much the people were probably exposed to mutagens that can develop during cooking. Subjects also had blood drawn for DNA analysis.

What they found: There wasn't a strong association between meat consumption and rectal cancer. But it does appear that the carcinogenic compounds that form in cooked meat are related to rectal cancer in men.

What it means to you: Eating meat—especially charbroiled or roasted meat—may increase your risk of rectal cancer.

Caveats: Subjects had to remember eating habits from up to several years before the interviews, and the researchers didn't have direct measurements of the subjects' exposure to carcinogens—just an estimate based on what foods they said they'd eaten.

Find out more: About polycyclic aromatic hydrocarbons, one of the carcinogens from grilled meat: http://www.atsdr.cdc.gov

Read the article: Murtaugh, M.A., Ma, K., Sweeney, C., Caan, B.J. and M.L. Slattery. "Meat Consumption Patterns and Preparation, Genetic Variants of Metabolic Enzymes, and Their Association With Rectal Cancer in Men and Women." Journal of Nutrition. April 2004, Vol. 134, pp. 776–784.

Abstract online: http://www.nutrition.org/