These statements were met with a media frenzy, and the expected furor from the meat industry. The most surprising thing, for me, is that anyone would be surprised by the IARC's statement.
Even the 2010 USDA Dietary Guidelines, as influenced by industry lobbying as they are, state (2):
...moderate evidence suggests an association between the increased intake of processed meats (e.g., franks, sausage, and bacon) and increased risk of colorectal cancer and cardiovascular disease.Although to be fair, the Guidelines do beat around the bush quite a bit, never directly stating that we should avoid processed meat. Instead, they recommend avoiding "solid fats", then list processed and red meats as possible sources of such fats.
As I detailed in my series "Is Meat Unhealthy?", there is abundant evidence that processed meat increases the risk of digestive tract cancers. We have consistent evidence from observational studies, human biomarker trials, and animal studies. And we have a clear mechanism. Science is never 100 percent conclusive, but this is about as close as it gets.
As far as fresh red meat is concerned, the risk is less clear, but I think the IARC's conclusion that it probably contributes to colorectal cancer risk is reasonable based on the evidence.
Some people are comparing the risk of eating processed and red meat to the risk of smoking cigarettes. This is utter nonsense. Smoking cigarettes is far more harmful to health than eating processed meat, and infinitely more harmful than eating fresh red meat. On average, cigarette smokers have three times higher mortality rates than non-smokers, and they die an average of 10 years earlier than non-smokers (3)!
In contrast, if you squint at the data hard enough, people who eat a lot of processed meat have a slightly higher mortality rate than people who don't. And people who eat a lot of fresh red meat have about the same mortality rate as people who avoid it. Also, fresh red meat is a highly nutritious food, whereas cigarettes don't supply any essential nutrients as far as I know... So although these foods probably do carry some risk, let's keep it in perspective and not get carried away.
My conclusion: eat bacon if you want to-- but don't think you're doing your health any favors.