Processed Meat and Cancer

Today, we bring you some important research on processed meat which has been classified as a Group 1 carcinogen.    

And how did the meat industry, government, and cancer organizations respond to that news? Here’s our first story.

“It is [perhaps] rare, in the history of nations, that one finds good reasons to render homage to the generosity and altruism of governments and those in power, but the birth of the International Agency for Research on Cancer (IARC) presents one of those rare occasions.” It all started with a single letter from a bereaved husband, relating the suffering of his wife after a cancer diagnosis, calling for governments to devote half of 1 percent of their military budgets to fight for life by attacking one of the greatest plagues that weigh on humanity. And, 18 months later, the IARC was born in the World Health Organization. With what overarching motive? Cancer prevention.

The IARC is best known for its monographs––book-sized reports evaluating whether or not some suspected carcinogen does in fact cause cancer. They are generally accepted as close to a final word as there is on whether or not something is carcinogenic. And their 114th monograph, published in 2018, was on meat. After thoroughly reviewing the accumulated scientific literature, a Working Group of 22 experts from 10 countries, after considering more than 800 different studies, concluded their 500-page report by establishing that something like a burger or pork chop is probably carcinogenic; probably causes cancer. But processed meat was placed as a Group 1 carcinogen––the highest level of certainty––meaning that according to the best available evidence, the consumption of processed meat causes cancer.

So, that means foods like bacon cause cancer; ham, hot dogs, breakfast links, lunch meat cause cancer. But their definition also includes, for example, turkey deli slices. Specifically, eating processed meat causes colorectal cancer––cancers of the colon or rectum, the second most deadly cancer worldwide after lung cancer, which is caused largely from smoking. Colorectal cancer is the second leading cause of cancer death here in the United States as well, and it doesn’t just strike older people. It’s also a leading cause of cancer and death from cancer earlier in life as well.

The meat industry wasn’t happy, calling it a “dramatic and alarmist overreach.” Speaking of dramatic and alarmist overreach, one ag group in Italy sent out a press release: “Just say no to terrorism on meat.”

The gloves were off. The meat industry in Canada tried to pressure the government to cut off funds to the IARC, asking the Health Minister to pull all funding from the agency after they dared to question meat. And the U.S. meat industry did the same thing. It’s no surprise the IARC is under siege by corporate interests, trying to challenge their cancer evaluations on Monsanto’s Roundup pesticide and meat, trying to discredit the agency and undermine financial support. Internal documents have revealed that Monsanto scientists, for example, “casually discussed ‘ghost-writing’ scientific papers and suppressing any science that conflicts with the company’s assertions of safety.”

The chemical industry has joined the corporate cacophony, calling the IARC monographs “dubious and misleading.” These are classic strategies straight out of the tobacco industry playbook. “But there is little to suggest that, as a corporate actor, ’Big Tobacco‘ differs fundamentally from, for example, ’Big Booze’ or ’Big Food’, for example.”

One recurring corporate talking point is that basically, the IARC never met a carcinogen it didn’t like. But the vast majority end up being categorized as just possibly carcinogenic, or there really aren’t sufficient data to make a determination either way. And look, they only spend time looking at substances for which there is already an existing body of scientific literature indicating a degree of carcinogenic hazard to humans. So, no wonder many of them end up, indeed, carcinogenic.

How did the IARC respond to all the criticism? The World Health Organization received a number of queries, expressions of concern, and requests for clarification following the publication of their meat and cancer report. They replied, hey, we never told anyone to stop eating processed meats—your body, your choice. They just indicated that reducing consumption of these products can reduce the risk of a leading cancer killer. So hey, you like cancer? You do you.

The IARC is just a research organization that evaluates the evidence on the causes of cancer; after that, what you do with that information is up to you. The American Cancer Society was nice and clear when it came to alcohol. When it comes to cancer, it is best not to drink. But they got a little more wishy-washy with processed meat, suggesting people can get away with just limiting their intake.

The European Commission was a little clearer. To reduce our risk of cancer, we should eat plenty of whole grains, pulses (which are beans, split peas, chickpeas, and lentils), vegetables and fruits, limit sugary, fatty, salty foods, and straight up avoid soda, sausage, and other processed meats. After all, in answering the question how much meat is safe to eat, the IARC replied that we don’t yet know whether a safe level exists, period.

In this next story, I quantify the risks of colon and rectal cancers from eating bacon, ham, hot dogs, sausage, and lunch meat.

In 2018, arguably the most prestigious cancer research institution in the world, the International Agency for Research on Cancer (IARC), the World Health Organization, published their report on processed meat, concluding that foods like bacon, ham, hot dogs, lunch meat, and sausage are cancer causing, classifying processed meat as a Group 1 carcinogen. “These findings,” conclude the director of the agency, “further support current public health recommendations to limit intake of meat.” Critics questioned putting processed meat in the same carcinogenic classification as asbestos or tobacco. Or, as a pesticide company roughly put it, how can eating processed meat fall into the same category as mustard gas?

The classifications only relate to the strength of evidence that the agent causes cancer or not––not how much cancer. This does not mean that they are all equally dangerous. It’s safer to eat a sandwich filled with pastrami than plutonium, even though they are both Group 1 carcinogens––both substances known to cause cancer in people.

Okay, so just how dangerous is meat? The relative risk of colorectal cancer was 18 percent for every 50 grams a day. Okay, so what exactly does that mean? Well, the 50 grams is about one hot dog, or two breakfast links, or two slices of Canadian bacon or ham. So, a daily sandwich with one or two slices of baloney would increase your colorectal cancer risk by 18 percent. But a half-pound pastrami on rye would bump it up more like 80 percent.

Okay, but what does the 18 percent increased risk really mean? One way to look at it is absolute risk versus relative risk. Assuming that the lifetime risk of colorectal cancer is about 5 percent (1 in 20), increasing your risk about 20 percent would only bump up your absolute risk of getting colorectal cancer from 5 percent to 6 percent. Now, on a population scale, an 18 percent drop in risk could mean about 25,000 fewer cases of colorectal cancer every year in the United States: 25,000 fewer families a year dealing with that diagnosis––if we swapped out the daily baloney sandwich for hummus, or chose veggie dogs instead. So, it all depends on how you look at it.

Colorectal cancer is our second leading cause of cancer death for men and women combined, after lung cancer. So, if you don’t smoke, colon and rectal cancer may be your greatest cancer nemesis. But we can drop the risk of getting it by about a fifth with a single dietary tweak: cutting a serving of processed meat out of our daily diet.

How does 18 percent increased cancer risk compare to other risky behavior? In my testimony before the Dietary Guidelines Scientific Committee, I made what may sound like a hyperbolic metaphor. I asked, “We try not to smoke around our kids; why would we send them to school with a baloney sandwich?” That is not hyperbole. According to the Surgeon General, living with a smoker increases your risk of lung cancer by 15 percent. So, breathing second-hand smoke day in and day out increases your risk of lung cancer almost as much as eating a serving of processed meat day in and day out increases your risk of colorectal cancer.

The meat industry responded by saying that the risks and benefits must be considered together before telling people what to eat or breathe. Think about all the baloney benefits. Lunch meat isn’t just about cancer, but convenience.

Indeed, processed meat isn’t just about cancer. An article railing against the World Health Organization’s “meat terrorism” cited the Global Burden of Disease studies comparing how many cancer deaths are caused by processed meat consumption, compared to tobacco or alcohol use. But if you look at the study they’re referencing, the 30-something thousand deaths attributable to higher processed meat intake are just the colorectal cancer deaths, and don’t also include the 100,000 deaths from diabetes, or the 400,000 deaths from heart disease. So, in actuality, we may be talking a half million deaths attributable to processed meat. And it’s not just colon and rectal cancer. If you look at the science since the IARC decision was published, processed meat may also increase the risk of prostate cancer, breast cancer, and pancreatic cancer.

Unfortunately, despite growing public health concerns about processed meat consumption, there have been no changes in the amount of processed meat consumed by U.S. adults over the last 18 years. Of course, it would have helped if the last Dietary Guidelines for Americans had happened to mention that processed meat was a carcinogen. An explicit and science-based statement on processed meat in the next Dietary Guidelines would certainly help. But the scientific committee made no such recommendation.

Sadly, even those diagnosed with colorectal cancer hardly improve their overall lifestyle after diagnosis, though that may be because “70 percent of cancer patients had never received nutrition advice from their [medical] providers during or after treatment.” That just blows me away.

“Despite the continued obfuscation of the issue by the meat industry—they learned well from the tobacco merchants—meat should continue to be a focus of public health action.” New York City is leading the way, passing legislation to ban processed meats from school meals. What a concept, not giving our kids carcinogens.

Meanwhile, the processed meat industry is trying to reformulate its products. It’s kind of like in the pharmaceutical area, where you try to mitigate the potential adverse effects of one drug by prescribing an additional drug. Like you could add fiber to hot dogs or something to try to counterbalance the risk, potentially reducing the cancer load by changing how it’s processed, rather than by banning processed meat altogether.

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