Today the International Agency for Research on Cancer (IARC; the cancer research agency of the World Health Organization) put out a press release on the effects of red meat and processed meats (cured, salted, fermented or smoked meats) on cancer risk (1).
They warn that the risk of colorectal cancer increases by 18% with each 50 gram of processed meat eaten per day (1). So, what does 50 grams of processed meat look like? Its about 2 slices of bacon, or 2.5 slices of bologna. (see photos here)
However, this is not new information. We have known about the carcinogenic risk of eating processed meats for a long time. IARC lists a few reasons why red meat and processed meat increases risk of cancer, but also that it is not yet completely understood how the risk of cancer increases with intake of these meats (2).
One factor that contributes to the carcinogenic effects are compounds called nitrosamines (2). These compounds form when meat products containing nitrites (either added in processing, or naturally occurring) are heated (3). As a result, the nitrites react with the amines (part of the protein) in the meat, forming nitrosamines.
Also, the Physician's Committee for Responsible Medicine has a campaign called "Drop the Dog" to raise awareness about this.
IARC did not suggest an amount of red meats or processed meats that is safe, but the fact of the matter is that is not necessary for us to eat them. So, next time you are shopping for groceries, why not pick up a pack of veggie dogs instead of hot dogs? There are so many amazingly delicious vegan alternatives to meat products out there!
(1) International Agency for Research on Cancer. (2015) IARC monographs evaluate cinsumption of red meat and processed meat. http://www.iarc.fr/en/media-centre/pr/2015/pdfs/pr240_E.pdf accessed on October 26, 2015.
(2) International Agency for Research on Cancer. (2015). Q & A on the carcinogenicity of the consumption of red meat and processed meat. http://www.iarc.fr/en/media-centre/iarcnews/pdf/Monographs-Q&A_Vol114.pdf accessed on October 26, 2015.
(3) Issenberg, P. (1976). Nitrate, nitrosamines, and cancer. Feredation Procedings, 35:6, 1322-1326.