The World Health Organization's (WHO) International Agency for Research on Cancer (IARC) on Oct. 26 announced a finding that red meat and processed meat are "probably carcinogenic to humans." As expected, meat constituencies railed against the report.
"After thoroughly reviewing the accumulated scientific literature, a working group of 22 experts from 10 countries convened by the IARC Monographs Programme classified the consumption of red meat as probably carcinogenic to humans (Group 2A), based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect," the report said. "This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer."
It added: "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."
That Group 1 rating means "the agent is carcinogenic to humans." Group 2A means "the agent is probably carcinogenic to humans." It's notable the finding was based on a review of scientific literature, not on any new and original research. WHO is an agency of the United Nations.
The North American Meat Institute (NAMI) said the report "defies both common sense and numerous studies showing no correlation between meat and cancer and many more studies showing the many health benefits of balanced diets that include meat. Scientific evidence shows cancer is a complex disease not caused by single foods and that a balanced diet and healthy lifestyle choices are essential to good health."
“It was clear sitting in the IARC meeting that many of the panelists were aiming for a specific result despite old, weak, inconsistent, self-reported intake data," said Betsy Booren, Ph.D., NAMI vice president of scientific affairs. “They tortured the data to ensure a specific outcome."
The IARC committee concluded that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18 percent. “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,” said 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.”
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.
"These findings further support current public health recommendations to limit intake of meat,” says Dr. Christopher Wild, director of IARC. “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.”
The report noted 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.
NAMI's Booren added: “Red and processed meat are among 940 agents reviewed by IARC and found to pose some level of theoretical ‘hazard.’ Only one substance, a chemical in yoga pants, has been declared by IARC not to cause cancer. IARC says you can enjoy your yoga class, but don’t breathe air (Class I carcinogen), sit near a sun-filled window (Class I), apply aloe vera (Class 2B) if you get a sunburn, drink wine or coffee (Class I and Class 2B) or eat grilled food (Class 2A). And if you are a hairdresser or do shiftwork (both Class 2A), you should seek a new career.
“Followers of the Mediterranean diet eat double the recommended amount of processed meats," she concluded. "People in countries where the Mediterranean diet is followed, like Spain, Italy and France, have some of the longest lifespans in the world and excellent health."