posted by Carl V Phillips
Continuing with a debunking of the claims in this recent press release by University of Minnesota toxicologist Stephen Hecht, which was picked up by various non-expert health sites and news outlets. Yesterday we pointed out how toxicology claims, in the context of anti-THR, turn out to be almost entirely lies, in part because they are used to make claims that contradict the epidemiology; epidemiology trumps toxicology in the same way that looking out the window to see if it is raining trumps looking at yesterday’s weather forecast for today.
Today we will address some of the background lies about epidemiology that Hecht included in this press release — claims that have nothing to do with this particular bit of research, but that he needs in order to fool people into believing the research matters. [Note: some of the posts in this blog will be pretty self-contained, while others will appeal to extensive bodies of knowledge that cannot fit into one post. This is an example of the latter. More detail on the particular points will probably eventually be covered in this series, but in the meantime you can find more in more in-depth writing about THR by me, Brad Rodu, casaaa.org, and tobaccoharmreduction.org.]
smokeless tobacco is a known cause of oral cancer
The subtle little problem with that claim is that it is just not true, at least not in the current US context that is noted as the focus of concern in the press release. The tiny subset of the epidemiology that Hecht and his co-conspirators like to cite to support this claim consists of one old study of archaic US products and various studies of Asian products, most of which are not even tobacco. They then try to trick the reader into ignoring the many studies of the products that people actually use in the US and Scandinavia, which have shown that if there is any risk, it is too small to measure.
This is not to say that we know there is absolutely no risk, of course, but it is clear that the risk is very small and not even clearly established to be nonzero, whereas Hecht is communicating that it is large and clearly exists.
Evidence has been accumulating for years that people who use smokeless tobacco have an increased risk of cancer of the mouth, esophagus and pancreas.
This claim of an accumulation over time is more patently false than the claim that there is a risk. The belief that smokeless tobacco causes oral cancer traces mostly to the one major study of a niche US product (almost never used and impossible to even find anymore) done in the 1970s, and to a lesser extent some low-quality, smaller studies from that era or earlier. By the 1990s, those results had not been replicated and several major studies had instead found no risk from modern products; further research continued to support this new conclusion of no measurable risk after all. That is apparently what passes for “has been accumulating for years” at the University of Minnesota.
As for pancreatic cancer, “accumulating for years” refers to two studies from the 2000s which claimed to find a risk, but which actually flatly contradict each other (i.e., if you choose to believe one of them is the right way to measure the effect, then the other agrees with the rest of the evidence, which suggests there is no measurable risk). The accumulating evidence on esophageal cancer showed an amazingly consistent pattern of no risk, until recently when just a few studies suggested an association; the weight of the evidence clearly remains on the no measurable risk side. (Also, most of the “evidence” that there is risk from smokeless tobacco from the 2000s came from a single research group that was clearly cooking their results; I suspect this blog will get to them eventually.)
That said, notice the subtle phrasing here: “people who use…have an increased risk…” Now this might just be accidental — Hecht seems to have no qualms about stating out-and-out falsehoods — but it might be another case of lying with a technically true statement. It turns out that, in the US population, many smokeless tobacco users are former smokers and many are current smokers (who, thanks to people like Hecht, do not realize they would be much better off using the smokeless exclusively). Smokers definitely have much higher risks of cancer of the mouth and esophagus (pancreas is a bit trickier). Moreover, people who choose to use nicotine products have somewhat poorer health on average, apart from any effects of the behavior.
So, the statement as phrased is not actually claiming that smokeless tobacco causes these diseases, but rather it says that if you do not control for confounding then you will find an association.
Hecht had to present these lies, which have nothing to do with his research, in order to be able to sell his message that he had found a cause of cancer. He would look really stupid if he said “Lookee everyone! I have found the reason why these products [which do not seem to cause a measurable risk of cancer] cause cancer!” Better to be a liar than to look stupid, eh?
So how about both?