Scientists from around the world convened in Lyon, France--a city famed as the world's gastronomical capital--this October to declare that local delicacies, such as andouille sausage and pork salami, are now classified carcinogens, placing them in the same category as smoking. The absurdity of that conclusion highlights the growing futility of efforts to classify certain chemicals, foods, and activities as either "carcinogenic" or not.
Such classifications are supposed to inform consumers and their health care providers, but they do more to confuse and mislead.
In this case, a division of the World Health Organization (WHO), known as the International Agency for Research on Cancer (IARC), is charged with regularly assessing the cancer risks of various substances and then classifying them within one of several categories, which include "carcinogenic," "probably carcinogenic," "possibly carcinogenic," and "not classifiable."
At the conclusion of the Lyon meeting, IARC announced that it is classifying processed meat as "carcinogenic" and red meat (e.g., beef, lamb, and pork) as "probably carcinogenic." But I bet at least some of the WHO delegates enjoyed a few sausages themselves during their trip, because they understand that such classification systems don't tell us anything about actual risks. They simply indicate that at some exposure level and under some circumstance a substance might increase cancer risk, and even then maybe by just an insignificant amount.
IARC explains: "The classification indicates the weight of the evidence as to whether an agent is capable of causing cancer (technically called 'hazard'), but it does not measure the likelihood that cancer will occur (technically called 'risk') as a result of exposure to the agent." [Emphasis added]
But classifying substances or activities as "hazardous" is not particularly helpful. For example, walking your dog (where you might slip and fall) and skydiving both present the hazard of bone breakage, but the risks are vastly different. Yet IARC "logic" could place walking the dog and skydiving in the same "hazardous" category.
This explains why "smoking tobacco" is listed as a carcinogen along with wood dust, salted fish (Chinese style), painting houses for a living, and now eating baloney sandwiches. Not surprisingly, the news media popularize this absurdity with outrageous headlines like "Processed meats rank alongside smoking as cancer causes - WHO (The Guardian). Yet you can't even begin to compare the theoretical risks associated with eating baloney sandwiches or working as a painter with actual smoking-related deaths that total nearly half a million people annually in the United States alone.
In addition, such hazard-based listings downplay, if not completely ignore countervailing benefits. Nonetheless, IARC admits in a summary of its decision in The Lancet Oncology: "Red meat contains high biological-value proteins and important micronutrients such as B vitamins, iron (both free iron and haem iron), and zinc."
The Lancet Oncology summary also discusses studies that attempt to assess the risks of cancer from red meat and processed meats. It explains that the largest body of epidemiological studies relates to colon cancer, including 29 studies (14 cohort studies and 15 "informative" case control studies). Of these, 14--or just less than half--reported associations between meat consumption and colon cancer; the others found no associations.
The article then cites a meta-analysis--a study that pools data from other studies to run a larger analysis--as a key support for the classifications. Meta-analyses have notable limitations, but this one might have been compelling if the meta-analysis found a strong relationship between colon cancer and meat consumption. It didn't.
The meta-analysis found a weak association, one that many researchers would dismiss as not useful for drawing conclusions. Still, IARC scientists used the meta-analysis to suggest that people who eat 100 grams (a serving is about 85 grams) of red meat daily may expect a 17 percent increased risk of colon cancer, and people who eat 50 grams (a serving is about 28 grams) of processed meat daily can expect an 18 percent increased cancer risk.
This seems scary, but it's not as substantial as it sounds. According to the National Cancer Institute, the average person's risk of getting colon cancer is 5 percent. So an 18 percent increased risk associated with processed meat consumption would increase the cancer risk to 5.9 percent. If true, this is not to be dismissed, but it's a risk that can be managed. It certainly should not be placed in the same category as smoking!
The so-called public health advocates at the World Health Organization should do much better. How about simply advocating a balanced diet? That's something along the lines of consuming plentiful amounts of fruits, vegetables, whole grains, and protein from vegetable sources, as well as moderate amounts of animal proteins from fish, poultry, and red meat. And that can include an occasional sausage and regular consumption of red meat, whether you enjoy it in Lyon or at home.