It has been four years since the World Health Organization classified processed meats as Group 1 carcinogens. The agency cited there is sufficient evidence that these products do, in fact, cause cancer in humans. A new review, out this week, challenges this somewhat broad classification, arguing instead that the strongest evidence shows varying levels of carcinogenic property dependent upon whether or not the meat has nitrites.
According to the International Agency for Research on Cancer (IARC), which is a chapter of the World Health Organization, processed meat is that which has undergone one or more methods for preserving and enhancing flavors. You may be familiar with these processes known as: curing, salting, smoking, and fermentation, but there are others.
Of course, some food producers use sodium nitrite to cure meat or to enhance color or as a preservative to increase the product’s shelf life. You may be more familiar with processed meats by the names we call them in the grocery aisle. These include: bacon, beef jerk, canned meats, corned beef, ham, and sausage.
At the same time it is extremely important to note that not all processed meats contain nitrites; or, rather, that not all processed meats rely on nitrites for their processing. British and Irish sausages, for example, are nitrite-free but sausages from the United States and continental Europe—like frankfurters (hot dogs), pepperoni, and chorizo—are not.
Now, it is also crucial to advise that the current Department of Health guidance counsels red and processed meat is relatively safe in quantities up to 70g.
However, lead author Brian Green comments that not all processed meats carry the same amount of cancer risk. As such, the Institute for Global Food Security researcher goes on to say, “There is more research to be done before we can definitively prove causality regarding processed meat and cancer—there are so many variables when it comes to people’s diets. But based on our study, which we believe provides the most thorough review of the evidence on nitrites to date, what we can confidently say is that a strong link exists between nitrite-containing processed meat, such as frankfurters, and CRC.”
The results of this study have been published in the journal Nutrients.