Eating bacon and hot dogs raises a person’s risk of getting colon cancer, the World Health Organization said Monday, and eating non-processed, red meat might do so as well. The agency classified the consumption of red meat as “probably carcinogenic to humans,” and processed meats as “carcinogenic to humans,” based on evidence linking the foods to colorectal and other cancers.
The new status puts processed meat, such as ham and sausages, in the highest-risk “group 1” category, along with substances like tobacco and asbestos. In a statement, the agency said its experts “concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18 percent.” Red meat is in the level below, called “2a” by the organization, and it encompasses beef, veal, pork, lamb, mutton, horse, and goat.
“These findings further support current public-health recommendations to limit intake of meat,” said Christopher Wild, director of the WHO's International Agency for Research on Cancer. “At the same time, red meat has nutritional value.”
The 2a designation is “the equivalent of a take-care label,” as the University of Michigan’s Risk Science Center explains. It only means people should eat less of the foods, not give them up entirely. French-fry oil and shift work, for example, are also both considered “probable” carcinogens by the organization.
In April of last year, IARC called attention to studies linking red and processed meats to colorectal, esophageal, lung, and pancreatic cancers and said exploring the connection further was “a high priority.” The WHO has also said part of meat’s cancer risk might be explained by cooking temperatures. The high-heat, charring method that gives steak and sausages a blackened look might also create cancer-causing compounds.
The designation is predicted to spark hand-wringing within the meat lobby. Shalene McNeill, the executive director of human nutrition research at the National Cattlemen's Beef Association, told Reuters that the group believes the science linking cancer and red meat is far from settled. “Cancer is a complex disease that even the best and brightest minds don't fully understand,” McNeill said. “Billions of dollars have been spent on studies all over the world and no single food has ever been proven to cause or cure cancer.”
It’s true that it’s difficult to prove causality for cancer. A major 2012 study found a small, positive association between meat consumption and cancer. But as the British science writer and pharmacologist David Colquhoun points out, it didn’t totally control for smoking or alcohol consumption.
It’s also worth noting that the new designation doesn’t mean bacon is as deadly as smoking. Cancers from cigarettes and alcohol—other substances in group 1—kill far more people globally than does cancer from processed meat. The higher ranking only means that the evidence linking processed meat to cancer is stronger than that for red meat.
But it does mean processed meat is one food people could cut back on if they want to be healthier.
“Processed meats have been suspect for a while and red meat has been linked to cardiovascular disease, so there is good reason to limit these foods,” said Marleen Meyers, an assistant professor in the division of hematology and medical oncology at the Perlmutter Cancer Center in New York. “For many health reasons, consumed meat should be lean and unprocessed but not necessarily avoided.”
For starters, you can opt for turkey this Thanksgiving rather than ham: There’s no sign that white meat causes cancer—at least not yet.
New plant-based meats are an exciting development for nutrition and the environment.