The World Health Organization has deemed that processed meats — such as bacon, sausages and hot dogs — can cause cancer.
In addition, the WHO says red meats including beef, pork, veal and lamb are "probably carcinogenic" to people.
A group of 22 scientists reviewed the evidence linking red meat and processed meat consumption to cancer, and concluded that eating processed meats regularly increases the risk of colorectal cancer. Their evidence review is explained in an article published in The Lancet.
The conclusion puts processed meats in the same category of cancer risk as tobacco smoking and asbestos. This does not mean that they are equally dangerous, says the International Agency for Research on Cancer — the agency within the WHO that sets the classifications. And it's important to note that even things such as aloe vera are on the list of possible carcinogens.
In a Q & A released by the IARC, the agency says that "eating meat has known health benefits," but it also points out that the cancer risk increases with the amount of meat consumed. As we've reported, studies show that the heaviest meat eaters tend to have the highest risk.
The IARC says high-temperature cooking methods (such as cooking meat in direct contact with a flame) produce more carcinogenic compounds. However, the group says there were not enough data "to reach a conclusion about whether the way meat is cooked affects the risk of cancer."
Susan Gapstur of the American Cancer Society says the society recommends "consuming a healthy diet with an emphasis on plant foods and limiting consumption of processed meat and red meat," she told us in a written statement.
The recommendation, Gapstur tells The Salt, is based on research. For instance, a systematic literature review on colorectal cancer published in 2011 by the World Cancer Research Fund found a statistically significant, 16 percent increased risk of colorectal cancer associated with each 3.5 ounces of red and processed meat consumed per day. As the ACS points out, this is an amount of meat roughly equivalent in size to a deck of cards. In its new evaluation, the IARC offered a different risk assessment: It concluded that eating about 1.8 ounces of processed meat daily will increase the risk of colorectal cancer by about 18 percent. We should note, we're talking relative risk here, and the chances of developing colorectal cancer are fairly low to begin with.
The Lancet paper points out that red meat also contains "high biological-value proteins and important micronutrients such as B vitamins, iron and zinc." And the North American Meat Institute says lots of research points to the benefits of red meat consumption.
"Scientific evidence shows cancer is a complex disease not caused by single foods and that a balanced diet and healthy lifestyle choices are essential to good health," writes Barry Carpenter, president of the North American Meat Institute, in a statement on the new WHO classification.
Carpenter says it's important to put this new classification in context. "IARC's panel was given the basic task of looking at hazards that meat could pose at some level, under circumstance, but was not asked to consider any off-setting benefits, like the nutrition that meat delivers or the implications of drastically reducing or removing meat from the diet altogether," the statement concludes.