The IARC examined some 800 studies during a meeting of 22 health experts in early October and has classified processed meat as “carcinogenic to humans” on its group one list along with tobacco and asbestos, for which there is “sufficient evidence” of cancer links.
According to experts, eating processed meats like hot dogs, sausages and bacon can cause colorectal cancer in humans, and red meat is also a likely cause of the disease. Each 50g portion of processed meat eaten daily, the equivalent of one hot dog or two slices of bacon, is said to increase the risk of colorectal cancer by 18%. Evidence of a link between processed meat and stomach cancer was also observed.
As for red meat, it has been classified as probably carcinogenic in IARC’s group 2A list, joining glyphosate, the active ingredient in many weedkillers. The classification for red meat, defined as all types of mammalian meat including beef, lamb and pork, reflected “limited evidence” that it causes cancer. The IARC found links mainly with colorectal cancer, which is a cancer that starts either in the colon or rectum, but also observed associations with pancreatic and prostate cancer.
According to Dr Kurt Straif of IARC, “for an individual, the risk of developing colorectal (bowel) cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed”.
The Canadian Meat Council, which represents meat packers such as Maple Leaf Foods and the Canadian-based units of Cargill and JBS, rejected the findings as simplistic, while trade group North American Meat Institute said the IARC report “defies common sense.”
Shares of most meat companies were little changed after the announcement. Tyson Foods fell slightly after a rating cut by JP Morgan to “neutral,” which focused on the company’s shrinking market share in packaged meat.
According to estimates cited by the IARC, 34,000 cancer deaths per year worldwide are attributable to diets high in processed meat, and around 1 million due to tobacco smoking.