The World Health Organization published a study in October 2015 that connects eating processed meat (and to a lesser extent red meat) to cancer. These items are now classified as carcinogens. Below is an excerpt from the FAQ of the study:
Red meat was classified as Group 2A, probably carcinogenic to humans. What does this mean exactly?
In the case of red meat, the classification is based on limited evidence from epidemiological studies showing positive associations between eating red meat and developing colorectal cancer as well as strong mechanistic evidence.
Limited evidence means that a positive association has been observed between exposure to the agent and cancer but that other explanations for the observations (technically termed chance, bias, or confounding) could not be ruled out.
Processed meat was classified as Group 1, carcinogenic to humans. What does this mean?
This category is used when there is sufficient evidence of carcinogenicity in humans. In other words, there is convincing evidence that the agent causes cancer. The evaluation is usually based on epidemiological studies showing the development of cancer in exposed humans.
In the case of processed meat, this classification is based on sufficient evidence from epidemiological studies that eating processed meat causes colorectal cancer.
Most people did not hear about it, which is normal, but the ones who did had a lot to say, and none of it was unexpected. Some people gloated (vegans) and others just pulled out that get out of jail free card “everything in moderation”. While I believe that moderation is acceptable of many things, it is not true of everything and we need to stop hiding behind it. A truer sentiment would be “I know it is harmful and I don’t care.” I can get behind that, but saying everything is fine for us in moderation is an excuse to eat junk and pretend we don’t know why we feel terrible.
Here is a link to the WHO website were the FAQ and study are located.