I’m sure you’ve heard.
On Monday, the International Agency for Research on Cancer (IARC), part of the World Health Organization, published a heavy anticipated report categorizing the consumption of processed meat as “carcinogenic to humans” (Group 1) on the basis of sufficient evidence for colorectal cancer. Additionally, the consumption of red meat was classified as “probably carcinogenic to humans” (Group 2A).
I was fascinated by how the media would communicate such a complex scientific subject matter. If you’ve read my blog for a while, you will know that misrepresentation of scientific findings in popular media is a big pet peeve of mine. And while scaremongering on this point would fit nicely into my encouragement to eat less meat, I feel such decisions should be taken on the basis of accurate information – no more, no less.
Let’s look at titles first, shall we? I’m focusing on English media here, though I particularly appreciated the Tagesschau’s #Wurstgate (“sausagegate”) hashtag in their reporting too.
“Carcinogens: They’re What’s for Dinner” – Take Part
“If meat causes cancer, what can we eat?” – CNN
“Bacon, hot dogs and processed meats cause cancer, WHO says” – PBS
“Meat Is Linked to Higher Cancer Risk, W.H.O. Report Finds” – New York Times
“Eating red and processed meat isn’t going to increase your risk of cancer by that much” – The Verge
“How Red Meat Joined the 478 Other Things That Might Give You Cancer” – Bloomberg Business
oh and of course: “News Reports Point to Dramatic and Alarmist Overreach By IARC on Meat Vote” – North American Meat Institute
What a difference just a title makes, right?
However, the WHO did a good job at publishing an FAQ cheat-sheet that explained the methodology behind and reasons for this categorization, as well as what it means. Thus, once you move past the headline (but how many people today read the small print below the headline?), most qualified their statements pretty satisfactorily. Still, some news outlets got a little lost in translation.
For instance, the grouping (Group 1 versus Group 2A) does not refer to the difference in absolute cancer risk, but to the strength of evidence. I.e., although processed meat joins cigarettes as a Group 1 carcinogen, the risk of getting cancer from eating processed meat is still much smaller than getting cancer from smoking. This did not prevent PBS, however, from proclaiming that “Processed meat now falls into “group 1,” meaning it ranks as high as tobacco smoking, the most dangerous variants of human papillomavirus (HPV) and asbestos exposure in terms of causing cancer. Red meat lands in “group 2A” with inorganic lead.“
Also, most media picked up the estimate that eating an additional 50g of processed meat daily would increase colorectal cancer risk by 18%, but not all focused on putting that into perspective. The reader is left wondering – How large is the risk now? And should I risk increasing it by 18%? The problem here is that you can really just speak of statistical occurrence, not individual risk. Thus, the New York Times fumbles: “a person’s risk of colorectal cancer rises by a factor of about 1.1 or 1.2 for every serving of processed meat consumed per day. This means that based on the report, diets high in processed meat could be expected to contribute to about 30,000 deaths per year across the globe.” But this is useless information on a personal level, since risks are specific to your current diet and lifestyle. Diluting the higher risk of meat-loving countries by the billions of low-income global citizens that do not eat significant amounts of processed meat just doesn’t make sense.
In contrast, the Verge provides a nice analogy (though they don’t explain which population they are focusing on, I imagine it’s the UK): “Suppose you followed 1,000 people over the course of their lifetimes; about 61 people would get colorectal cancer on average, according to Casey Dunlop, a health information officer at Cancer Research UK. Based on the IARC’s findings, if you were to follow a group of 1,000 people who ate the most red and processed meats throughout their lives, about 66 would get colorectal cancer. If you followed the 1,000 people who consumed the least red or processed meats, only 56 would get colorectal cancer.” Though I can’t double-check the numbers, this is a way to present the data that actually can be pictured by the reader. The only way to do it better is… to actually make a picture.
This is what Bloomberg did in their very cool analysis. They focus on the overall relevance of the meat = carcinogen announcement, in a great example of graphics use.
Listing the different carcinogen suspects like this shows readers easily what weight the finding of “definitely carcinogenic” should have – it’s rather damning, though processed meat is in good company.
Also note how this presentation makes the grouping crystal-clear, and the explanation on the side is simple, straight-forward and to-the-point.
The analysis also highlights other identified carcinogens, allows readers to learn more about any one of them simply by clicking, and links to the original papers that explain the evidence. That, my friends, is good journalism.
Bottom line: Eating less meat is better for you and the environment. That is actually not a new discovery, though the WHO putting its weight behind it might influence governments to overthink their dietary recommendations. Yet, maybe the North American Meat Institute’s snarky interpretation of the science will skew their view:
“Red and processed meat are among 940 substances reviewed by IARC found to pose some level of theoretical ‘hazard.’ Only one substance, a chemical in yoga pants, has been declared by IARC not to cause cancer,” said Barry Carpenter, NAMI President and CEO. “IARC says you can enjoy your yoga class, but don’t breathe air (Class I carcinogen), sit near a sun-filled window (Class I), drink wine or coffee (Class I and Class 2B), eat grilled food (Class 2A), or apply aloe vera (Class 2B). And if you are a hairdresser or do shiftwork (both Class 2A), you should seek a new career.”
How did you learn about the WHO study? How did the media in your country report on it?