Bacon Can Cause Cancer But that Doesn't Mean You Have to Stop Eating It

We got to the bottom of the WHO's new classification of processed meats as a carcinogen.

Oct 26 2015, 6:40pm

A pile of bacon in a pan. Photo by Zach Copley/Flickr

On Monday, the world woke up to the news that the World Health Organization has classified processed meats like bacon and hot dogs as carcinogens and everyone kind of lost their shit.

The WHO's International Agency for Research on Cancer announced it had categorized processed meats as carcinogenic to humans and red meat as possibly carcinogenic to humans, after analyzing decades worth of research on the topic.

It found strong links between processed meats and the risk of colorectal cancer, and possible links between red meat and pancreatic, prostate, and colorectal cancer. In fact it said for every 50 grams of processed meat a person eats daily (that equals about two slices of bacon), their risk of colorectal cancer increases by 18 percent. It defined red meat as any mammalian muscle meat (so beef, veal, venison, pork) and processed meat as meat that has been transformed through salting, curing, smoking, or other means (so sausages, jerky, bacon, hot dogs).

But what does it all mean? Do you really have to swear off bacon for the rest of your life to avoid cancer? And is that turkey jerky really as bad for you as cigarettes?

First let's break down what the classifications mean. Red meat was listed as possibly carcinogenic to humans, or Group 2A, meaning there isn't enough evidence from human studies to say it definitively causes cancer, but there's a lot of evidence from other kinds of studies, like on animals. Processed meat was listed as carcinogenic to humans, also called a Group 1 classification. It's the strongest assertion the IARC makes, and it's true that tobacco products and asbestos are also classified as Group 1 carcinogens. But that doesn't mean bacon is as bad for you as smoking, according to Dr. David Wallinga, the senior health officer for the Natural Resources Defense Council.

"The classifications reflect how strong the base of evidence is," Wallinga told me over the phone. "It doesn't say anything about how strong of a carcinogen that particular thing is. It's not saying eating hot dogs is as potent at causing cancer as being exposed to asbestos."

Instead, the classification just means that (with both asbestos and processed meats) the body of evidence showing a link to cancer is strong enough, in the eyes of IARC, to label it a full-blown carcinogen.

"I didn't think it was news that hot dogs aren't good for you."

How about that 18 percent increased risk of cancer? Does your risk go up that much every time you have a slice of bacon? Not quite, Wallinga says, because that link is based on daily consumption. In other words, the more processed meat you eat on a regular basis, the higher the risk. So people who eat two slices of bacon every day are at an 18 percent higher risk of getting colorectal cancer than someone who never eats bacon.

That said, the risk of colorectal cancer should be taken seriously, Wallinga pointed out. Colorectal cancer is the third most common cancer in both men and women and the second-leading cause of cancer death in the US, according to the American Cancer Society, which estimated nearly 50,000 people will die of colorectal cancer in the US this year. The new classification shows the more processed meat you include in your diet, the higher your risk of this deadly disease.

It's also important to note that this decision was based on decades of research on the topic, which is why it may not be all that surprising to some. The IARC making a classification is definitely significant, as many public health organizations turn to the IARC when making decisions about guidelines or recommendations, but it's far from new information for anyone who has been paying attention. These kinds of headlines emerge every time a new study adds to the mounting evidence.

"I didn't think it was news that hot dogs aren't good for you," said Dr. Yoni Freedhoff, an Ottawa-based physician and professor who has a blog on nutrition and diet.

Freedhoff said the takeaway here should be that if you're eating processed meats as a staple in your diet, it would be in the best interest of your health to make some changes. It doesn't mean you can never eat a hot dog again, but that we could all stand to curb how much meat we are eating. How much you choose to curb that is really up to you, and depends on both the risks you're willing to take and how much you're willing to change your habits, Freedhoff said.

"The goal with any dietary indulgences that might not be good for you is to have the smallest amount of them in your life that allows you to still enjoy your life," Freedhoff said. "There are lots of things that are carcinogens and lots of those things taste delicious."