Last week, the World Health Organization (WHO) listed red meat as probably carcinogenic and processed meat was listed as carcinogenic. The report did not specify the differences between grass-fed and grain-fed meat, but at least one researcher said a grass-fed vs. grain-fed diet is not an influencing factor. However, there is research to suggest that grass-fed meat may contain more CLA and Omega-3s, which have cancer fighting properties
Red meat is defined as muscle meat such as beef, veal, pork, and lamb, among others. It is probably carcinogenic based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect.
Processed meat has been transformed through salting, curing, fermenting, smoking or other processes that enhance the flavor or improve the preservation of the meat. Processed meat includes bacon, sausage, hot dogs, salami, beef jerky, ham as well as canned meat and meat-based sauces. It has been added to the IARC (International Agency for Research on Cancer) category 1 classification, based on evidence from large observational studies (more than 800 studies that investigated a dozen types of cancer were reviewed). Some research found that the compound that gives meat its color, heme, may damage the lining of the bowel. Processed meat joins a list with a broad range of substances such as mineral oils, estrogen, ionizing radiation and diesel engine exhaust
There were 22 scientists from 10 countries who were a part of the WHO’s IARC Monographs Programme that reviewed the science. The final report on red meat as a probably carcinogen stated that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%. “For an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed,” says Dr Kurt Straif, Head of the IARC Monographs Programme. “In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.”