Maybe vegetarians are right? The World Health Organization is saying that hot dogs, bacon, cold cuts, and other processed meats raise the risk of several cancers, including colon and stomach cancer. Red meat probably raises the risk of cancer as well.
Many health groups have been warning people away from processed meats for some time, but WHO's subsidiary cancer agency, the International Agency for Research on Cancer (IARC), headquartered in Lyon, France, is now saying it, too. The IARC analyzed many years of research on processed meats and cancer and has issued a very definitive statement that puts processed meats in the same risk category as smoking or asbestos.
This does not mean that hotdogs or bologna are as bad as cigarettes, however, just that it is known to be carcinogenic. To put the risk in perspective, the IARC said that research estimates that 34,000 cancer deaths per year worldwide are linked to diets heavy in processed meat, compared to 1 million deaths a year linked to smoking, 600,000 a year to alcohol consumption, or 200,000 a year to air pollution.
A group of researchers from the IARC evaluated more than 800 studies from many countries about the association between meat and cancer. The studies looked at more than a dozen types of cancer over the past 20 years that had been conducted in populations that had diverse diets.
Based on that evaluation, the IARC has classified processed meat as "carcinogenic to humans," and specially noted an association specifically to colon cancer.
The report when on to say that red meat contains some important nutrients for humans, but still labeled it "probably carcinogenic," with links to colon, prostate, and pancreatic cancers.
The agency said there is not enough data to define how much processed meat is too dangerous, but did say that the risk increases the more a person eats. Analysis of 10 of the studies suggested that a 50-gram portion (about 1.75 ounces) of processed meat a day increases the risk of colorectal cancer over a lifetime by about 18%. This is a serving about the size of a small hot dog or two or three slices of bologna.
The WHO researchers defined processed meat as anything transformed to improve its flavor or to preserve it, including sausages, canned meat, beef jerky, and smoked meat. They defined red meat as muscle meat from any mammal.
The American Cancer Society has been recommending for years that people eat less processed meats and red meat.