The Physicians Committee for Responsible Medicine (PCRM) popped up while I was in medical school. It seemed reasonable: promote good nutrition, promote ethical treatment of research animals. For many of my classmates, it became a “gateway” animal rights organization. Their literature always sounded reasonable. While they say they “promote alternatives to animal research”, what they mean is that they aggressively target animal researchers with lawsuits designed to shut them down. (For the safety of the researchers involved, I’ll not link to specific cases.)
While they say they promote proper individual nutrition and nutrition policies, what they actually do is aggressively promote vegetarian—preferably vegan—diets. While there is research supporting the role of high-fat meat based foods increasing the risk of certain diseases, there is very little published literature showing that vegan diets actually improve important outcomes like heart attacks or death. PCRM strongly promotes these two agendas disingenuously, allowing their ideology to trump science. For example, one of their current campaigns in Las Vegas features this billboard:
There actually is a debate. The debate isn’t over whether hot dogs are a great food (personally, I find them to be delicious, but eat them infrequently). The statement means…what? If you eat a hot dog you’ll get some sort of cancer? Like, right away?
By means of explanation:
“Hot dogs gamble away your most precious asset—your health,” says PCRM nutrition education director Susan Levin, M.S., R.D. “Processed meats like hot dogs can increase your risk of diabetes, heart disease, and various types of cancer. Like cigarettes, hot dogs should come with a warning label that helps people in Las Vegas understand the health risk.”
If “processed meats” are the only food you eat, you’re not doing it right. A healthy diet is varied, and meats should be a small part of daily meals. Meats are better when they are lower-fat. There is some evidence in the literature that processed meats are associated with an increased risk of diabetes in some populations. The analogy with cigarettes is completely off base. There is a clear, causal, dose-dependent relationship between cigarette smoking and heart disease, death, and lung cancer. So where are they getting the “hot dogs cause cancer” idea?
(“Processed meat” means many different things. Some contain nitrates, some do not. Some are smoked, some are not. There are thousands of types of processed meats, so we already have the problem of finding an operational definition.)
Reading further, we see a statistic:
According to the American Institute for Cancer Research, just one 50-gram serving of processed meat (about the amount in one hot dog) consumed daily increases the risk of colorectal cancer, on average, by 21 percent.
Where does the “21 percent” come from? It comes from a report published by the World Cancer Research Fund (see pp. 122-124). The report is interesting, but focusing on the section on “processed meat” we see a few problems. As the authors state, there is no agreed-upon definition of “processed meat” which “is likely to contribute to observed heterogeneity.” In other words, the wildly different results between studies may be due in part to the lack of a consistent definition. If we are interested in assessing the risk of an exposure, it’s difficult to come up with a valid conclusion of the exposure isn’t actually defined. The report isn’t an actual study, but an analysis of multiple studies, most of which have confidence intervals crossing “1”, meaning that processed meat may confer either risk or protection.
While I doubt that processed meats protect us from colon cancer, it does show that the evidence to date is a bit gummy. It seems likely based on various epidemiologic studies that processed meats may contribute to colorectal cancer. But this is very different from the statement on the billboard.
So what’s the point of the billboard? Is it up to promote healthy eating? How about a positive message like, “Eating vegetables is good for you!” This is clearly not health promotion but propaganda, an exaggeration of the truth meant to frighten people.
I’m not suggesting you go out and buy a pack of hot dogs; you’d be better off with broccoli. But deceiving the public in this way is immoral and probably counterproductive—depending on what your real goals are.