WHO says processed meat causes cancer
WHO's International Agency for Research on Cancer (IARC), looked at the evidence about whether processed meat and red meat cause cancer.
IARC evaluated all the evidence available and decided to classify consumption of processed meat as "carcinogenic to humans" and consumption of red meat as "probably carcinogenic to humans."
IARC didn't do its own field research. It went through more than 800 epidemiological studies on cancer and red and processed meat and weighed those findings together, IARC spokeswoman Véronique Terrasse says.
Although the findings of the study are not absolute, IARC is determined that there is more than enough evidence to conclude eating processed meat can cause cancer.
The IARC article, which appears in The Lancet Oncology, isn't clear on what's included in processed meats but in other documentation IARC lists hot dogs, ham, sausages, corned beef and beef jerky, but excludes processed poultry. IARC said that further research is still needed but it is better for people to limit their consumption.
For red meat and processed meat, Terrasse says, "The classification gives you an idea about the strength of evidence that it causes cancer but it doesn't give you any clue about how much you need to be exposed to have cancer, it's not a classification about the risk."
Kurt Straif, who heads the IARC unit responsible for the report, said that the IARC Working Group views that meta-analysis as "the best estimate of risk."
An IARC press release incorrectly attributes the risk estimate. It says it was the IARC experts who "concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%."
Researchers frequently associate eating red and processed meat with bowel cancer, but there has also been significant research linking processed meat to stomach cancer and red meat to pancreatic or prostate cancer, as well as limited research linking both meats to several other cancers.