STATS ARTICLES 2008
Kids Claim They’re Getting Cancer from Hot Dogs
Trevor Butterworth, July 25, 2008
CNN asks if vegan-doc group’s controversial YouTube ad featuring children claiming they're getting colon cancer from hot dogs is true, but just how reliable is CNN's fact-checking?
“Your child is going to die!” is the most powerful way for an activist group to advance a cause. No matter how insubstantial or unwarranted the claim, the message that “your child is going to die” will give all but the most robotically-wired rationalists pause to wonder whether there just might be some risk.
Enter a trio of adorable children against the backdrop of a school cafeteria. They talk in the knowing fashion of adults that was used to great effect by Monster.com during the Superbowl:
Child #1: I thought I would live forever. I was dumfounded when the doctor told me… I have late-stage colon cancer.
Child #2: Deciding between surgery and radiation wasn’t easy, who knows what sort of side effects I’ll have?
Child #3: it has been tough on my husband and kids and me. Cancer affects the whole family.
Voice over: “Even small amounts of processed meats lead to adult cancers.”
"It's outrageous," says Dr. Ronald E. Kleiman, Unit Chief, Pediatric Gastroenterology and Nutrition, at Mass General Hospital, the video is exploiting children in the worst possible way. It's appalling to see a child used to advance a political agenda."
The ad was created by The Cancer Project, an affiliate of the Physician’s Committee for Responsible Medicine. Despite advertising itself as a committee of physicians, it appears that anyone can join the PCRM for $20 dollars. And while the group advocates for better nutrition and cancer prevention, its not a mainstream medical organization, and its tactics and recommendations have been slammed by the American Medical Association, which complained in a letter to the New York Times that the group’s recommendations were “irresponsible and potentially dangerous to the health and welfare of Americans.”
“…the absurd suggestion virtually to eliminate meat and dairy products from the American diet demonstrates the close relationship of the Physicians Committee for Responsible Medicine to animal "rights" groups and their disregard for the health and welfare of the American public… the A.M.A. formally requested the committee to terminate the inappropriate and unethical tactics used to manipulate public opinion against the use of animals in biomedical research. We urge the committee to change its tactics and join the medical and scientific communities to protect and preserve human welfare.”
To her credit, CNN’s Elizabeth Cohen described the Cancer Project’s ad as the work of “an animal rights group that wants us all to be vegans,” and that their claim was overstated; but if the intent was to reassure the public that the advert was out of line, CNN failed to explain what the data really says about eating meat and cancer.
Cohen observed that there is “some” research, by the American Institute for Cancer Research showing that if you eat one hot dog a day – or the equivalent amount of processed meat, your risk of cancer increases by 21 percent. And that the reason for this was probably to do with the presence of nitrites as preservatives. "The problem experts believe it is in nitrates in the processed meats," she says. "That's apparently what's causing the cancer link." Except the science doesn't actually support this statement.
Scary numbers need context
While there may be a connection between very high consumption of smoked foods and cancer of the upper gastrointestinal tract, says Kleinman, there is not an established relation between the normal consumption of processed foods and the risk of cancer of the bowel.
Moreover, a 21 percent increase is not statistically significant, the rise could have happened by chance. The AICR came by its number through the World Cancer Research Fund report on cancer and diet in 2007, which based its recommendations on meat consumption in large part on a 2005 study published in Journal of the American Medical Association, Meat Consumption and Risk of Colorectal Cancer. The significance of this study was that it seemed to nail the link between colon cancer and red meat after years of inconclusive research results.
Among the 148,610 men and women participating in the study, those who consumed large quantities of red and processed meat over a ten-year period were 30 percent more likely to get colon cancer and 40 percent more likely to get rectal cancer. But STATS found that the 30 percent increase in risk for colon cancer was not statistically significant – nor did it apply to women, where there was no correlation between meat consumption and colon cancer.
The same study did find, however, a statistically significant increase in rectal cancer (71 percent) among those who had a high intake of red meat - but this did not apply to processed meat.
For long term consumption (over 10 years), red meat did not affect the rate of upper colon cancer at all (although there was a slight, but not statistically significant, increased risk for lower colon cancer). The study did confirm an increased risk – about 43 percent more – for rectal cancer among long term carnivores. For heavy consumers of processed meats, there is an increased risk for lower colon cancer, but not statistically significant increases in the risk for rectal or upper colon cancer.
It should be noted that the increased risk for colorectal cancer associated with high meat consumption affects about one percent of these meat-eaters over the course of their lifetime. It should also be noted that there are environmental factors affecting the risk for colon cancer, and these include smoking, obesity, alcohol consumption and lack of exercise.
But even this study may overstate the risk. The World Cancer Research Fund did not include the largest ever pooling study to consider the relationship between colon cancer and meat. Preliminary details of “Meat and fat intake and colorectal cancer risk: A pooled analysis of 14 prospective studies,” by Eunyoung Cho, and Stephanie A. Smith-Warner for the Pooling Project of Prospect Studies of Diet and Cancer Investigators, were published in 2004 and there was no association between higher red meat consumption (including processed meat) and a higher colorectal cancer risk among 725,258 subjects.
As for nitrites, which are present in salt and used in meat to prevent spoilage and protect against botulism (essential for meats cooked at relatively low heat, such as hot dogs), 90 percent of our exposure actually comes from vegetables, notably spinach, beets, radishes, celery, and cabbages. Only 10 percent comes from meat. "Nitrites are a part of everyday life in a wide variety of foods," says Dr. Kleinman, and that though it's biologically plausible that they could cause cancer, there's not much to actually link them to cancer. The American Medical Association conducted a literature review of the research into nitrites and cancer and found that
“…epidemiological studies cannot confirm any association between the presence of nitrites (or nitrates) in food and the formation of NOCs and the causation of human cancer. In fact, studies that suggest a link between nitrites in food and cancer have largely been disputed due to these studies’ inability to exclude confounding factors, such as recall bias.”
Moreover, the AMA notes that the level of nitrites in meat fell by 80 percent between 1975 and 1997.
But the fear that nitrites are carcinogenic is not only unsubstantiated, recent research published in the Proceedings of the National Academy of Sciences suggests that they may in fact help protect the heart and reduce the severity of heart attack.
CNN has repeatedly run versions of the segment asking whether the Cancer Project's ad is accurate; but in its attempt to fact check the ad's claims, it served a reminder that it's the data that appears to be true that needs to be double checked. Instead of calling attention to the politically-motivated use of children to seed panic and, as Kleinman notes, undermine genuine public health efforts, CNN ended up, in effect, helping to promoting the group's agenda by failing to put the numbers in an accurate context.