Bacon Causes Cancer? Sort of. Not Really. Ish.

PERHAPS NO TWO words together are more likely to set the internet aflame than BACON and CANCER. So when the World Health Organization classified processed meat as a group 1 carcinogen, the same category as tobacco—

Hold on. Let me stop right here. Eating bacon is not as bad as smoking when it comes to cancer. Just no.

The way WHO classifies cancer-causing substances, on the other hand? Maybe a little dangerous to your mental health. Because it is really confusing.

Here’s the deal: The WHO’s International Agency for Research on Cancer weighs the strength of the scientific evidence that some food, drink, pesticide, smokable plant, whatever is a carcinogen. What it does not do is consider how much that substance actually increases your risk for actually getting cancer—even if it differs by magnitudes of 100.

The scientific evidence linking both processed meat and tobacco to certain types of cancer is strong. In that sense, both are carcinogens. But smoking increases your relative risk of lung cancer by 2,500 percent; eating two slices of bacon a day increases your relative risk for colorectal cancer by 18 percent. Given the frequency of colorectal cancer, that means your risk of getting colorectal cancer over your life goes from about 5 percent to 6 percent and, well, YBMMV. (Your bacon mileage may vary.) “If this is the level of risk you’re running your life on, then you don’t really have much to worry about,” says Alfred Neugut, an oncologist and cancer epidemiologist at Columbia...