World Health Organization Adds Processed Meats to List of Carcinogens

Issue 27 Summer/Fall 2016

But expert panel also cautioned that the overall cancer risk from consumption is slight

Processed meats - foods such as hot dogs, ham and bacon - have been added to the World Health Organization's list of carcinogens, due to a slight rise in risk for colorectal cancer in people who regularly eat these meats.

strips of bacon

In their decision late last year, the 22-member WHO panel placed processed meats into their Group 1 category of carcinogens, alongside items such as alcohol, asbestos, and tobacco smoke.

The panel stressed, however, that diets rich in processed meats nowhere near match the cancer threat from those other carcinogens. "This does NOT mean that they are all equally dangerous," the panel said in a statement released at the time the decision was announced.

Red meat in general was placed in the "probable" carcinogen category by the WHO panel, which added that the risk from red meat was extremely small and should not be a cause for concern.

Speaking to The New York Times, Dr. John Ioannidis, chair of disease prevention at Stanford University, agreed that people should not be overly fearful that meat might raise their odds for malignancy.

"There's some risk involved, but it's much less than for smoking or alcohol," said Ioannidis, who was not a panel member. "I think it would be an exaggeration to say based on this that no one should be eating red or processed meat."

To help put the WHO risk assessment into perspective, Ioannidis said that while smoking leads to a 20-fold risk for lung or other forms of cancer, a person's risk for colorectal cancer would rise by only a factor of 1.1 or 1.2 for every serving of processed meat they ate per day.

Even then, he said, "there is still a lot of uncertainty" as to how much processed meat consumption might add to the global death toll from cancer.

The WHO panel defined processed meats as those, "transformed through salting, curing, fermentation, smoking or other processes to enhance flavor or improve preservation." It said it based its decision on data from human research - mostly observational studies.

There was only "limited evidence" available for the panel's decision to list red meat as a probable carcinogen, the Times noted, and again the risk was largely confined to colorectal cancer.

Speaking to the Times, Susan Gapstur, vice president of epidemiology at the American Cancer Society, said the WHO decision is in line with the ACS' current dietary guidelines. Those guidelines suggest that people consume fish, poultry or beans instead of processed and red meat, and that they limit red meat intake to leaner cuts and smaller portions.