WHO’s meat warning triggers backlash
World health authority faces claims it is overstating risks, not for the first time
The meeting on hotdogs and beef jerky was, ironically, held in the temple of fine dining — Lyon, France — where the scientists could dine on steak tartare and slow-cooked pig’s cheeks.
For eight days, an august panel of experts assembled from around the globe met in France to weigh the evidence on meat. Their deliberations would end in a declaration this week that processed meat is carcinogenic to humans, and red meat “probably” too — a proclamation that not only garnered wild- eyed headlines (“Processed meats as big a threat as cigarettes” London’s Daily Mail claimed, wrongly). It also raised fresh criticism over how the 67-yearold Geneva-based health authority communicates risks — and uncertain science — to the public.
One leading Canadian epidemiologist called the cancer ruling on bacon, sausages, biltong, beef jerky and other salted, cured, smoked or similarly prepared meats a “considerable overcall” of the available evidence.
Dr. Gordon Guyatt, a professor of medicine at Hamilton’s McMaster University, says the warning is largely based on less-rigorous, “observational” studies, where researchers follow a group of people over time and then count up how many develop cancer.
Guyatt, who doesn’t eat red meat, also points out the increase in relative risk — about an 18 per cent increased risk of colorectal cancer for every 50 grams of processed meat eaten daily (roughly equivalent to two strips of bacon) — was “very modest” and might easily be attributable to other confounding factors observational studies can’t fully adjust for. Still, he says the cancer warning is in keeping with an analysis published by his group earlier this year, which concluded that 73 of 289 strong recommendations issued by the World Health Organization over a recent five-year stretch were based on weak evidence. “Their inferences go beyond what is appropriate,” charges Guyatt.
In this case, he argues, the more appropriate caution would have read: “Low quality evidence suggests that intake of these meats may cause cancer.”
WHO has faced charges before of overstating risks, including a travel advisory on Toronto during the 2003 SARS epidemic, turning the city into an international “SARS pariah” (BBC) that Toronto medical officials called a “shocking” and “gross misinterpretation” of facts.
This week’s meat warning came from IARC, the International Agency for Research in Cancer, which, although part of WHO, isn’t tainted with SARS, Ebola and other perceived failures, says Dr. Ross Upshur, head of clinical public health at the University of Toronto. “It is without question,” Upshur says of IARC, “a reputable authority in the field of cancer.”
The cancer agency convened 22 experts from 10 countries. The group prepared draft documents in advance, reviewed more than 800 studies on cancer in humans and then deliberated at IARC in Lyon to decide which of five categories of carcinogens meat warrants.
In the end they added processed meat to Group 1 — meaning “there is sufficient evidence from epidemiological studies that eating processed meat causes colorectal cancer.” In doing so, hotdogs and bacon joined hundreds of other agents in the same category, from asbestos and tobacco to UV radiation and Chinese-style salted fish.
In a Q&A background document posted on its website, IARC stressed that just because something has been classified in the same category as smoking doesn’t mean it’s equally dangerous, because it doesn’t assess the level of risk.
But beyond that, observers say there was little practical advice or suggestions for consumers about what all this means.
IARC said the data “did not allow conclusions” about whether the risk is higher in children, the elderly, women or men, whether people who have already had colon cancer should stop eating meat, whether the way meat is cooked changes the risk, whether we should all become vegetarians or whether a “safe level” of meat — red or processed — even exists.
In the end, despite the fretting headlines and indignant cries from meat producers, the classification simply reinforced a 13- year- old recommendation by WHO, and numerous other health groups, that people who eat meat should do so in moderation.
“Nobody is saying ban meat, nobody is saying ban farming or ban the meat industry. There’s been no move to regulate,” says the University of Toronto’s Upshur. “WHO is simply informing the public that there are health risks that are measurable and tangible associated with continuing this behaviour.”