Not all bacon. I just said that to get your attention.

The problem isn’t the meat itself; it’s the additives sodium nitrate and sodium nitrite. Added to preserve color and prolong shelf life, in the body these form carcinogenic (cancer-causing) nitrosamines. Nitrates and/or nitrites can be found in bacon, sausage, hot dogs, beef jerky, lunch meats, and virtually any prepackaged meal containing meat (including pepperoni and salami).

The Evidence

The World Cancer Research Fund (WCRF) reviewed more than 7000 clinical studies investigating the links between cancer and diet choices, and concluded:

“World Cancer Research Fund International recommends avoiding processed meat. This is the conclusion of an independent panel of leading scientists who, following the biggest review of international research ever undertaken, judged the evidence that processed meat increases the risk of bowel cancer to be convincing. This review was done in 2007 and was subsequently confirmed in 2011.”

Even more compelling to me, this study out of the University of Hawaii in 2005 showed that consumption of processed meat products including nitrates and nitrites increased the risk of pancreatic cancer by 68%.

The American Cancer Society further notes that high consumption of processed meat over a decade is associated with a 50% increase in the risk for bowel and rectal cancers—where “high consumption” for men is about two slices of bacon OR half a hot dog, 5-6 days per week, and for women, a similar amount 2-3 days per week.

The Solution

This doesn’t mean you can’t ever have bacon again, but you should be vigilant about the meat products you buy. Health food stores carry bacon (and sausage, and hot dogs) that do not contain nitrates or nitrates, and they’ll usually advertise that they are nitrate-free on the front of the package. If not, flip it over and read the ingredients. If it lists nitrates or nitrites, put it back.

You can also make your own sausage: free range ground turkey + a little salt, pepper, sage, and cumin tastes quite similar to the prepackaged varieties.

I’d recommend caution with deli meats and processed meat products purchased in restaurants, though—you can easily end up falling into the “high consumption” category if you eat out a lot. When you can opt for unprocessed meats, do so.

But if (for instance) your office caters in grinders from the deli for a lunch meeting and your choice is between eating it or going hungry, you can offset the negative impact of the nitrates and nitrites with some extra vitamin C. Ascorbic acid helps block the conversion of nitrates and nitrites to carcinogenic nitrosamines, so it can help protect you in a pinch. So choose a side dish that’s rich in Vitamin C (such as broccoli, bell peppers, and citrus fruits), or keep some extra Vitamin C tablets in your purse or your desk, just in case.