Health & Fitness

Say what? Bacon causes cancer? Dig in to recent study results

Dr. Akshay Gupta
Dr. Akshay Gupta

Recently, the world of red meat and processed-meat eaters and their producers was rocked by a research study that claimed eating these products can cause cancer. Here are some answers to the questions that you may have about that news.

Says who?

The International Agency for Research on Cancer is an intergovernmental agency that’s part of the World Health Organization of the United Nations. Its primary objective is to conduct research into the causes of cancer. It collects and publishes data regarding the occurrence of cancer worldwide and on the risks to humans posed by a variety of agents, mixtures and exposures.

How does the IARC make these decisions?

They collect a bunch of experts from all over the world and look at all the relevant scientific data on a particular agent (red meat and processed meat in this case) and decide whether there is sufficient evidence to classify the agent as a carcinogen.

Are they for real?

Well, kind of. The IARC is an agency of WHO specifically dedicated to cancer issues. The IARC has been around since 1970 and has published a series of important papers establishing or refuting the role of several potential carcinogens.

OK, so what do these experts say about processed meat?

They have classified the consumption of processed meat as “carcinogenic to humans” and placed it in “Group 1” of potential carcinogens. Group 1 means there is sufficient evidence that these agents cause cancer, and it’s the worst category. Some other commonly known agents in Group 1 are tobacco, asbestos, arsenic, UV radiation, tanning beds, formaldehyde, mustard gas, etc.

Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking or other processes to enhance flavor or improve preservation. Examples of processed meat are: bacon, sausages, hot dogs, salami, corned beef, beef jerky and ham as well as canned meat and meat-based sauces.

OK, so what’s the risk?

There is an 18 percent increase in the risk of colon cancer per 50 grams per day of consumption of processed meat.

How much is that?

Well, 50 grams is a little less than 2 ounces, so it’s a couple of strips of bacon a day or one hot dog every day.

So is it really as dangerous as smoking?

Not even close. Processed meat increases the risk of colon cancer by about 18 percent. In comparison, active smoking increases the risk of lung cancer by 10- to 13-fold — which equals 1,000 percent to 1,300 percent increase in risk. So yes, there is an increased risk of colon cancer by processed meats, but the increase in the risk is modest at worst.

What about regular non-processed red meats?

The study says, “There is limited evidence in human beings for the carcinogenicity of the consumption of red meat,” which means that there are conflicting reports on its role in causing cancer. They have placed red meat as “probably carcinogenic to humans.” That means it lands in Group 2A.

Again, the research is very conflicted on whether there is any direct link between colon cancer and red meats. However, there is some convincing evidence that consumption of more than 50 grams of red meat per day does increase the risk of precancerous colon polyps by 20-25 percent. Again, not a huge increase, but enough to cause some concern.

OK, so what’s the bottom line?

My recommendation — reduce your consumption of processed meat as much as possible. Yes, bacon is bad for you — but who really thought that it wasn’t? Even the most ardent bacon lovers would admit it’s not quite “healthy eating.”

We already knew that bacon causes an increased risk of heart disease, and now we know it can cause cancer as well — although it’s not quite in the same league as tobacco. So limit it and stay well below an average of 50 grams a day.

Also, do eat some good stuff as well, such as green veggies, other high-fiber foods, carrots, etc. Regular exercise and keeping a check on your body weight are also key. Doing these things will counteract the effects of bacon.

And as far as red meat is concerned, well, I think the jury is still out on that. There is no convincing link to cancer, but there is some convincing evidence that it can cause precancerous colon polyps. Again, adding some green veggies to your diet is going to help.

And most important — at the risk of sounding like a broken record — I’d recommend that if you eat red meat or processed meat on a regular basis, and you are over 50, please get a colonoscopy!

Dr. Akshay Gupta is a gastroenterologist at Idaho Gastroenterology Associates ( in Boise. He completed his medical school from the All India Institute of Medical Sciences in New Delhi, India. He did his internal medicine residency at the University of Pittsburgh and completed a gastroenterology and hepatology fellowship at the University of Michigan. Gupta received additional training in interventional endoscopy, ERCP and endoscopic ultrasound at the Moffitt Cancer Center in Tampa, Fla.