WHO says processed meats cause cancer, red meats probably do; reporters explain how

As expected, the World Health Organization today released a report saying "that bacon, sausage and other processed meats cause cancer and that red meat probably does, too," Peter Whoriskey reports for The Washington Post. "The report by the influential group stakes out one of the most aggressive stances against meat yet taken by a major health organization, and it is expected to face stiff criticism in the U.S." (Sausage can cause cancer, says a WHO report)

What exactly is processed meat, and why does it cause cancer? "Processed meat has been modified to either extend its shelf life or change the taste, and the main methods are smoking, curing or adding salt or preservatives," James Gallagher and Helen Briggs report for BBC News. "Simply putting beef through a mincer does not mean the resulting mince is 'processed' unless it is modified further. Processed meat includes bacon, sausages, hot dogs, salami, corned beef, beef jerky and ham as well as canned meat and meat-based sauces."

"Suspected carcinogenic chemicals can form during meat processing," Gallagher and Briggs write. "These include N-nitroso compounds and polycyclic aromatic hydrocarbons. Cooking the meat at high temperatures, especially on a barbecue, can also produce these dangerous chemicals. However, the WHO's experts admit that the cancer risk is 'not yet fully understood.' Each 50g of processed meat per day—fewer than two slices of bacon—increased the risk of cancer by 18 percent. Each 100g of red meat per day increased the risk by 17 percent although the WHO admits there is limited evidence."

While the World Cancer Research Fund says to eat as little red meat as possible, 'meat is still a good source of protein, B vitamins and minerals such as iron and zinc," Gallagher and Briggs write. Frankie Phillips, spokesperson for the British Dietetic Association, told BBC, "The message is to still include red meat in the diet because it is a good source of key nutrients. The general message is it's OK to eat some red meat but perhaps to look at ways of increasing the amount of plant-based foods—in particular, pulses." (Read more)