Processed meats, red meat linked to cancer
PARIS — Bacon, hot dogs and cold cuts are under fire: The World Health Organization threw its global weight behind years of experts’ warnings and declared on Monday that processed meats raise the risk of colon and stomach cancer and that red meat is probably harmful, too.
Meat producers are angry, vegetarians are feeling vindicated and cancer experts are welcoming the most comprehensive pronouncement yet on the relation between our modern meat-eating lifestyles and cancer.
The WHO’s International Agency for Research on Cancer in Lyon, France, analyzed decades of research and for the first time put processed meats in the same danger category as smoking or asbestos. That doesn’t mean salami is as bad as cigarettes, only that there’s a confirmed link to cancer. And even then, the risk is small.
The results aren’t that shocking in the U.S., where many parents fret over chemicals in cured meats and the American Cancer Society has long cautioned against eating too much steak and deli.
But the UN agency’s findings could shake up public-health attitudes elsewhere, such as European countries where sausages are savoured and smoked ham is a national delicacy.
And they could hurt the American meat industry, which is arguing vigorously against linking their products with cancer, contending that the disease involves a number of lifestyle and environmental factors.
While U.S. rates of colon cancer have been declining, it is the No. 2 cancer for women worldwide and No. 3 for men, according to the WHO.
A group of 22 scientists from the IARC evaluated more than 800 studies from several continents about meat and cancer. The studies looked at more than a dozen types of cancer in populations with diverse diets over the past 20 years.
Based on that analysis, the IARC classified processed meat as “carcinogenic to humans,” noting links in particular to colon cancer. It said red meat contains some important nutrients, but still labelled it “probably carcinogenic,” with links to colon, prostate and pancreatic cancers.
The agency made no specific dietary recommendations and said it did not have enough data to define how much processed meat is too dangerous. But it said the risk rises with the amount consumed.
An analysis of 10 of the studies suggested that a 50-gram portion of processed meat daily — or about 1.75 ounces — increases the risk of colorectal cancer over a lifetime by about 18 per cent.
An ounce and three-quarters is roughly equivalent to a hot dog or a few slices of bologna, though it depends on how thinly it is sliced.
Overall, the lifetime risk of developing colorectal cancer in the U.S. is about one in 20, or five per cent, according to the cancer society. By the WHO’s calculations, having a cold-cut sandwich every day would only raise that to around six per cent.
Experts have long warned of the dangers of certain chemicals used to cure meat, such as nitrites and nitrates, which the body converts into cancer-causing compounds. It is also known that grilling or smoking meat can create suspected carcinogens.
“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,” Dr. Kurt Straif of the IARC said in a statement. “In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public-health importance.”
The cancer agency noted research by the Global Burden of Disease Project suggesting that 34,000 cancer deaths per year worldwide are linked to diets heavy in processed meat. That compared with one million deaths a year linked to smoking, 600,000 a year to alcohol consumption and 200,000 a year to air pollution.