New research out today from the World Health Organization finds that processed meats can cause cancer, and that red meat probably can, too.
WHO defines processed meats as "meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavor or improve preservation... Examples of processed meat include hot dogs (frankfurters), ham, sausages, corned beef, and biltong or beef jerky as well as canned meat and meat-based preparations and sauces."
The findings are sure to be controversial. The beef industry in the U.S. is huge - $95 billion a year - and the National Cattlemen's Beef Association has already weighed in saying it doesn't think there is evidence to support any link between red meat and cancer.
Here & Now's Robin Young talks with one of the researchers, Dr. Kurt Straif of the International Agency for Research on Cancer, which is part of the WHO, about the findings.
Interview Highlights: Kurt Straif
On the new findings that processed meats cause cancer
“Well, this is part of the IARC’s Monographs program, which is probably the world’s largest and most authoritative program to review what can cause cancer in humans, and this is in fact not one study written by IARC scientists. This is a review of all the published literature on the topic if red meat or processed meat can cause cancer, and that is done by the world’s leading experts that are convened by the IARC’s Monograph program. At the same time, we also watch that these experts don’t have any conflicts of interest – that they are not linked with stake holders, industry or advocacy groups on the other side.”
Why processed meat causes cancer
“We base the evaluation largely on the available studies that looked into eating processed meat and different types of cancers caused from epidemiological studies, largely very high-quality cohort studies. Now, when you ask what is it that causes this increase in cancer, there are several compounds that need to be discussed, but for none of them there’s clear conclusive evidence say that it’s heterocyclic aromatic amines that are produced at high temperature cooking, or that it’s PAHs - polycyclic aromatic hydrocarbons – that you know, for example, from barbecuing, or that it’s nitroso compounds that are found at higher levels in processed meat, or that it’s perhaps even it’s the heme iron, which is a kind of a constituting part of all kinds of meat.”
What is it about red meat - including pork - that might also be cancer-causing?
“We were very clear that pork is included in red meat, and so there is no scientific debate about that from the perspective of our international working group. And in terms of the red meat as compared to the processed meat, you also have the heme iron, you have the high temperature cooking, you have the heterocyclic aromatic amines."
What are heme iron and heterocyclic aromatic amines?
“Some are parts of the red meat already. Some are produced by various cooking or processing methods.”
What should people do?
“Well, you need to understand that this is an evaluation of what we call the hazard that answers the question if some exposures can in principle cause cancer in humans. The next step is then the accessing how much increase there is. And we know from the studies on the processed meat that you see about a 17 percent increase in risk of colorectal cancer per daily portion of 50 grams of processed meat. And the Monographs themselves do not make any recommendation. This is a purely scientific review, but this is then taken forward by national agencies or other international agencies, and if individuals are concerned they can, right now, stop or reduce eating processed meat.”
Would reducing the amount you eat be effective as well?
“Well, yes. That would already reduce your cancer risk, but from these studies that have been reviewed, there is no clear evidence that there is kind of a safe threshold of eating processed meat. So we see with every 50 gram portion, the risks increase further.”
- Kurt Straif, M.D., epidemiologist and section head of IARC Monographs at the International Agency for Research on Cancer, part of the World Health Organization.
This segment aired on October 26, 2015.