The World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) have evaluated the carcinogenicity of the consumption of red meat and processed meat.
Red meat
After thoroughly reviewing the accumulated scientific literature, a Working Group of 22 experts from 10 countries convened by the IARC Monographs Program classified the consumption of red meat as probably carcinogenic to humans (Group 2A). Based on limited evidence, the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect.
This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer.
Processed meat
Processed meat was classified as carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer.
Meat consumption and its effects
The consumption of meat varies greatly between countries, from a few percent up to 100 percent of people eating red meat, depending on the country, and somewhat lower proportions eating processed meat.
The experts concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18 percent.
Dr Kurt Straif, Head of the IARC Monographs Programme says,"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. In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance."
The IARC Working Group considered more than 800 studies that investigated associations of more than a dozen types of cancer with the consumption of red meat or processed meat in many countries and populations with diverse diets. The most influential evidence came from large prospective cohort studies conducted over the past 20 years.
Public health
"These findings further support current public health recommendations to limit intake of meat," says DrChristopher Wild, Director of IARC says, "at the same time, red meat has nutritional value. Therefore, these results are important in enabling governments and international regulatory agencies to conduct risk assessments, in order to balance the risks and benefits of eating red meat and processed meat and to provide the best possible dietary recommendations."
Note:
Red meat refers to all types of mammalian muscle meat, such as beef, veal, pork, lamb, mutton, horse, and goat.
Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavor or improve preservation. Most processed meats contain pork or beef, but processed meats may also contain other red meats, poultry, offal, or meat by-products such as blood.
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.