Yes, according to a new report from the American Institute for Cancer Research, a nonprofit based in Washington that studies links between diet and cancer.
As part of a larger, five-year review of more than 7,000 studies, the group’s specialists pored over 87 studies on the potential link between colorectal cancer and red meat, including beef, pork, and lamb. In excessive amounts, “red meat is a convincing cause of colorectal cancer,” the group said, although more research needs to be done on the precise mechanisms.
The group recommended limiting consumption of red meat to 18 ounces (cooked) per week. “It’s eating more than 18 ounces a week that increases risk substantially, said Karen Collins, nutrition adviser to the American Institute for Cancer Research.
The evidence against processed meat such as bacon, ham, sausage, and lunchmeat is “even more rigorous,” the group said, adding that it could find no level at which consumption of these products was safe. While that is a clear warning, it doesn’t mean you should never eat processed meat, just that you should eat it sparingly, Collins said.
Dr. Michael Thun, who heads epidemiology research for the American Cancer Society, endorsed the findings, saying that although red meat is less of a cancer risk than tobacco, obesity, and lack of physical exercise, it may be linked to a higher risk of cancer through several mechanisms.
Cooking meat by frying or grilling, he said, produces carcinogens, or cancer-causing chemicals, called heterocyclic amines. The fat in red meat also stimulates the release of bile salts that can be transformed into substances that damage the DNA in the colon. And red meat is high in iron-rich compounds, Collins said. Iron can generate cancer-causing substances (nitroso-compounds) as well as free radicals, which can damage DNA.
“The results of this new study came back so strongly,” Collins said. The evidence against meat is now “very compelling.”