Last month, I posted a summary of dietary factors that may influence a person’s risk of developing colon cancer. The following week, the World Health Organization (WHO) released their official evaluation of red meat and processed meats, now classifying processed meat as a carcinogen. Specifically, the report states:
“Processed meat was classified as carcinogenic to humans … based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer. “
This report rightfully received major media attention, but most accounts exaggerated the findings, and the risks. So what should we actually make of this report?
First, what are processed meats? Basically, any meat that has been preserved through salting, curing, smoking, or fermentation. Examples include ham, sausage, hot dogs, bacon, corned beef, or jerky. If you are a meat eater, you’ve eaten most of these foods, as they are unquestionably delicious. But don’t worry; you didn’t cause colon cancer by doing so.
What is the actual risk of eating processed meats? This is very difficult to quantify. The WHO estimates that the lifetime risk of colorectal cancer increases by 18% for every additional 50 grams of processed meat you eat per day. That’s roughly 2 strips of bacon per day. But keep in mind that estimating such a risk is fraught with uncertainty and is based solely on observation studies. There was enough evidence for the WHO to classify processed meats as a carcinogen, but the exact risk really isn’t known.
More importantly, the 18% increase is in relative risk. This is key. We are talking about an 18% increase above a baseline risk that is actually quite low. Specifically, the average lifetime risk of colon cancer is roughly 5%. If you eat 2 strips of bacon every single day of your life, you are potentially increasing your lifetime risk to 5.9%. That’s really not a big difference.
The bottom line is that everything has potential risks. But we need to balance these risks with the potential rewards. If you enjoy eating a hot dog from time to time, or you snack on beef jerky, or if you really believe that bacon makes everything better – it’s OK. Eating these foods in moderation will not alter your risk of colon cancer to any significant degree. We should all strive to eat a diet rich in vegetables, fruits, and whole grains, but the occasional cured meat won’t do you in.
-Christopher McGowan, MD, MSCR