I have quantified the risk of colon and rectal cancer from eating bacon, ham, hot dogs, sausage, and lunchmeat.
In 2018, the International Agency for Research on Cancer (IARC), part of the World Health Organization, perhaps the world’s most authoritative cancer research organization, released a report on processed meat, concluding that foods such as bacon, ham, hot dogs, lunchmeat, and sausage are carcinogenic, and classifying processed meat as a Group 1 carcinogen. “These findings further support current public health recommendations to limit meat consumption,” the agency chief concluded. Critics questioned classifying processed meat as a carcinogen in the same category as asbestos and tobacco. Or, as the pesticide companies wildly put it, why does eating processed meat fall into the same category as mustard gas?
As I explain in my video “How Much Cancer Does Processed Meat Cause?”, this classification relates only to the strength of the evidence that the substance causes cancer, not the degree of cancer. This doesn’t mean they all pose the same level of risk. Eating a sandwich with pastrami is safer than eating plutonium, even though both are Group 1 carcinogens. That is, both substances are known to cause cancer in humans. So how dangerous is meat? The relative risk of colorectal cancer was 18% for every 50 grams eaten per day. But what exactly does that mean?
50 grams is the equivalent of one hot dog, two breakfast links, or two slices of Canadian bacon or ham. This means that eating a sandwich with one or two baloney slices every day increases your risk of colorectal cancer by 18%. However, if you put half a pound of pastrami on rye, it will increase by almost 80%. Okay, but what does an 18% increase in risk actually mean? One way to look at it is absolute risk and relative risk. Assuming that the lifetime risk of colorectal cancer is about 5% (1 in 20 people), an increase in risk of about 20% only increases the absolute risk of developing colorectal cancer from 5% to 6%. Now, on a population scale, an 18% lower risk if you replace your daily baloney sandwich with hummus or choose a vegetable dog instead could mean about 25,000 fewer cases of colorectal cancer each year in the United States, and 25,000 fewer families each year dealing with that diagnosis. So, it all depends on how you look at it.
Colorectal cancer is the second leading cause of cancer death for men and women combined in the United States, after lung cancer. Therefore, if you don’t smoke, colon and rectal cancer can be your biggest natural enemy. However, by making one dietary change, you can reduce your risk of infection by about one-fifth. That means cutting one serving of processed meat out of your daily diet.
How does an 18% increased risk of cancer compare to other risky behaviors?In my testimony before the Dietary Guidelines Scientific Committee, I said something that may sound hyperbolic. I asked, “We try not to smoke around our kids, so why do we send them to school with baloney sandwiches?” That’s not an exaggeration. According to the Surgeon General, living with someone who smokes increases your risk of lung cancer by 15%. In other words, daily exposure to second-hand smoke increases your risk of lung cancer in much the same way that daily consumption of processed meat increases your risk of colorectal cancer.
The meat industry responded that the risks need to be considered along with the benefits before telling people what to eat and what to breathe. Lunchmeat isn’t just cancerous, it’s convenience.
In fact, processed meat doesn’t just cause cancer. The World Health Organization’s article denouncing “meat terrorism” cited the Global Burden of Disease study, which compared how many cancer deaths result from eating processed meat compared to using tobacco or alcohol. However, the studies they reference show that the approximately 37,000 deaths attributed to increased processed meat intake are only due to colorectal cancer, and do not include the 100,000 deaths from diabetes or the 400,000 deaths from heart disease. So in reality, as you can see below and at 4:06 in my video, processed meat may actually be responsible for 500,000 deaths.
It’s not just colon and rectal cancer. The science since the IARC decision was published shows that processed meat can also increase the risk of prostate, breast, and pancreatic cancer.
Unfortunately, the study found that “despite growing public health concerns about processed meat consumption, there has been no change in the amount of processed meat consumed by U.S. adults over the past 18 years.” Of course, it would have helped if the previous Dietary Guidelines for Americans had mentioned that processed meat is carcinogenic. It would certainly help to have a “clear and science-based statement on processed meat” in the next dietary guidelines. However, the Scientific Committee made no such recommendation.
Sadly, even colorectal cancer patients “have little overall lifestyle improvement after diagnosis,” which may be because “70% of cancer patients receive no nutritional advice from their (healthcare) provider during or after treatment.” That surprised me.
An article published in the journal Science of Cancer Research states that “meat should continue to be the focus of public health action, even though the meat industry continues to obscure the issue and has learned well from tobacco distributors.” New York City is leading the way, passing a bill banning processed meat from school lunches. Are we giving our children carcinogens? What a concept!
Meanwhile, the processed meat industry is trying to reinvent its products. This is similar to the pharmaceutical field, where people try to reduce the potential side effects of one drug by prescribing additional drugs. For example, rather than banning processed meat completely, changing the way it’s processed could reduce the amount of cancer by adding fiber to hot dogs to offset the risks.
doctor’s note
If you missed the previous video, see IARC: Processed meats like bacon cause cancer.
For my complete testimony on the U.S. Dietary Guidelines, please see highlights from the 2020 Dietary Guidelines Hearing.
