By Todd Neeley
DTN Staff Reporter
OMAHA (DTN) -- For the third time this year, an agency of the World Health Organization has dealt a blow to agriculture, this time issuing a finding that processed meats such as hot dogs and bacon are "carcinogenic to humans" and that red meat is "probably carcinogenic" to humans.
The International Agency for Research on Cancer, or IARC, issued the finding this week after a group of 22 scientists met in Lyon, France, to evaluate already published studies on the carcinogenicity of the consumption of red meat and processed meat, according to a news release from the IARC.
The IARC this summer classified the herbicide 2,4-D as possibly carcinogenic to humans. In March, the IARC classified glyphosate as a "probable carcinogen" to humans. In reaction to both IARC classifications, industry groups said the action was contrary to the majority of scientific research.
An IARC working group assessed more than 800 epidemiological studies on associations of cancer with red meat and processed meat consumption around the world.
In particular, the group focused on incidents of specific cancers and their association with red meat consumption.
"The working group classified consumption of red meat as 'probably carcinogenic to humans' (Group 2A)," IARC said in a news release. "In making this evaluation, the working group took into consideration all the relevant data, including the substantial epidemiological data showing a positive association between consumption of red meat and colorectal cancer and the strong mechanistic evidence. Consumption of red meat was also positively associated with pancreatic and with prostate cancer.
"The working group concluded that there is limited evidence in human beings for the carcinogenicity of the consumption of red meat. There is inadequate evidence in experimental animals for the carcinogenicity of consumption of red meat and of processed meat. In rats treated with colon cancer initiators and promoted with low calcium diets containing either red meat or processed meat, an increase in the occurrence of colonic pre-neoplastic lesions was reported in three and four studies, respectively."
When it comes to processed meat, the working group classified its consumption as "carcinogenic to humans" based on what the IARC said in its results was "sufficient evidence for colorectal cancer." In addition, the group said there was "a positive association with the consumption of processed meat was found for stomach cancer." In addition, the group said red meat consumption was "positively associated" with pancreatic and with prostate cancer.
INDUSTRY NOT IMPRESSED
The National Cattlemen's Beef Association Monday challenged the IARC's findings, saying in a news release the group's conclusions are not supported by science.
NCBA pointed to the working group's lack of consensus on the findings as an indication the jury is still out on red and processed meat's cancer associations.
"After seven days of deliberation in Lyon, France, IARC was unable to reach a consensus agreement from a group of 22 experts in the field of cancer research, something that IARC has proudly highlighted they strive for and typically achieve," NCBA said in a news release.
Shalene McNeill, a doctor sitting in on the working group proceedings, said the IARC's lack of consensus shows the difficulties the scientific community has had in understanding the disease.
"Cancer is a complex disease that even the best and brightest minds don't fully understand," she said in a news release statement. "Billions of dollars have been spent on studies all over the world, and no single food has ever been proven to cause or cure cancer. The opinion by the IARC committee to list red meat as a probable carcinogen does not change that fact. The available scientific evidence simply does not support a causal relationship between red or processed meat and any type of cancer."
NCBA said "most scientists" find it "unrealistic" to point to a single food as a cause of cancer.
"As a registered dietitian and mother, my advice hasn't changed," McNeill said. "To improve all aspects of your health, eat a balanced diet, which includes lean meats like beef, maintain a healthy weight, be physically active and, please don't smoke."
The Journal of the American College of Nutrition published the findings of a study that examined the relationship between read meat intake and colorectal cancer. That study found red meat "does not appear to be an independent predictor" of colorectal cancer risk.
Rather than questioning the IARC conclusion, the Canadian Cattlemen's Association said in a statement Monday consumers can take a proactive approach to preventing cancer while still consuming red meat.
"If consumers are concerned about the formation of compounds potentially associated with cancer risk while cooking beef, there are a number of simple things that can be done to reduce potential risk while enhancing the eating experience," the CCA said in a news release. "Approximately half of Canadians currently cook beef steaks to medium-well or well-done. It is known that cooking to lower levels of doneness can enhance tenderness and juiciness while also reducing the formation of substances which may increase cancer risk."
Todd Neeley can be reached at [email protected]
Follow him on Twitter @ToddNeeleyDTN
(SK/AG)
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