Processed meat like bacon, salami, and sausage can increase the risk of developing cancer, and should be placed in the same category as other well-known carcinogens like cigarettes and asbestos, according to an influential panel of international scientists.
The 22-person International Agency for Research on Cancer (IARC), a panel that advises the World Health Organization, reached that conclusion after reviewing hundreds of scientific studies. Their new statement about meat, published in the medical journal The Lancet on Monday, is the culmination of a year of deliberation among the panel members.
The IARC also concluded that red meat is “probably carcinogenic to humans,” but said there wasn’t enough evidence to classify it in the same category as processed meat.
A growing body of evidence points to a potential link between eating meat and developing certain types of cancer. But it’s more unusual for researchers to stake out a position that there’s a causal relationship between the two. According to the Washington Post, the IARC’s statement represents “one of the most aggressive stances against meat yet taken by a major health organization.”
It’s difficult to test how foods affect cancer risk. Isolated studies often deliver conflicting results, reporting that the same foods can both prevent and cause cancer. That’s why researchers say it’s important to step back and consider all of the evidence in the field. The IARC panel, for instance, reviewed 800 different studies on meat consumption.
The scientists on the IARC panel stressed that the risk of developing cancer from meat consumption still remains relatively small, and much lower than the cancer risk that stems from smoking. No one needs to worry about eating the occasional bacon sandwich. But Dr. Kurt Straif, one of the scientists on the panel, noted that “this risk increases with the amount of meat consumed” and “in view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.”
The news is poised to create significant controversy here in the United States, where the meat industry has repeatedly resisted efforts to link its products with health issues.
The North American Meat Institute, a group that lobbies for meat and poultry companies like Tyson Foods, said in a statement that the IARC’s conclusions “defy both common sense and dozens of studies showing no correlation between meat and cancer and other studies showing the many health benefits of balanced diets that include meat.” The group added that cancer prevention efforts should remain focused on efforts to encourage Americans to quit smoking and maintain a healthy weight.
Meat has come under increasing scrutiny for the potential harm that it poses not only to human health, but also to the environment. People who eat a high-meat diet contribute nearly twice the amount of diet-related greenhouse gas emissions to the atmosphere as a vegetarian does.
There have been some recent attempts to officially link eating less meat to protecting the environment; earlier this year, for instance, the U.S. Departments of Agriculture and Health and Human Services considered updating its federal dietary guidelines to include information about how meat affects sustainability. But that effort failed, thanks in part to significant pushback from industry groups like the North American Meat Institute. Outcry from the beef industry has also previously forced the USDA to backtrack on its endorsement of “Meatless Mondays,” an effort to encourage Americans to choose vegetarian options to help the environment.
Attempting to craft policy related to the potential relationship between meat and cancer could meet a similar fate. The USDA currently recommends the consumption of meat, including some processed meat like sausage.
“There is no group that could convince the meat industry that the science is definitive on the link to cancer, because the playbook of every industry under attack is to instill doubt in the evidence,” Bonnie Liebman, the director of nutrition at the Center for Science in the Public Interest, a consumer group that advises Americans to cut back on meat, told the Wall Street Journal.