Mar 09 2009
One of the consistent themes of SBM since its very inception has been that, when it comes to determining the efficacy (or lack thereof) of any particular medicince, therapy, or interventions, anecdotes are inherently unreliable. Steve Novella explained why quite well early in the history of this blog, and I myself described why otherwise intelligent people can be so prone to being misled by personal experience and anecdotal evidence. Unfortunately, as I have also demonstrated, it’s not just patients who can allow themselves to be misled by anecdotes, but certain physicians who do not understand the scientific method but in their hubris think that their “personal clinical experience” trumps science, clinical trials, and epidemiology.
None of this is to say that there aren’t frequent instances when applying data from population-based studies to individual patients is problematic. It can indeed be. However, it often goes beyond that, and, indeed, if there is one defining characteristic of a quack that I’ve never failed to find when looking at individual cases, it’s a belief that he is able to identify when a treatment works based on his own personal experience and anecdotes. Unfortunately, it’s not just quacks who sometimes fall prey to this, because humans are cognitively wired to infer causation from correlation. This tendency, which was no doubt adaptive early in our evolution, simply doesn’t work well when it is applied to medicine and science. Without a doubt, it is the key driver, for example, behind the widely believed myth that vaccines somehow cause autism and that chelation therapy and other biomedical quackery can “cure” autism, a view popularized most recently by the very popular but very ignorant Jenny McCarthy in the U.S. and before that by the outright dishonest Andrew Wakefield in the U.K.
One of the other reasons why testimonials for quackery seem convincing is because most people simply do not know enough about disease, be it my specialty (cancer) or any other disease, how it is treated, and what its natural course can be expected to be. That is why, when I came across an example of just such a testimonial, specifically a breast cancer testimonial, I saw what is known as a “teachable moment. This teachable moment occurred on the very popular science blog Pharyngula, written by the ever sarcastic biology professor from Minnesota, P.Z. Myers. It actually surprised me in that the usual topics on Pharyngula include evolution, biology, the pseudoscience known as “intelligent design” creationism, politics, and atheism. P.Z. doesn’t usually dabble much in the realm of medical quackery, but my guess is that he was attracted to this particular piece of pseudoscience because of the religious angle.
Specifically, the quackery under consideration is known as God’s Answer to Cancer (GAC). Basically, it looks a lot like any number of quack electronic devices that promise to cure cancer; examples include Bill Nelson’s Electro Physiological Feedback Xrroid (EPFX) machine (1, 2, 3), Hulda Clark’s parasite zapper, or Alan Back’s Advanced Bio-photon Analyzer. All of these devices promise, in essence, to use low level electrical energy to “boost the immune system” and “replenish your life energy” plus or minus an additional promise to “zap parasites” (Hulda Clark’s unique spin on these devices, in which she claims that all cancer, AIDS, and most other diseases are due to a liver fluke, which her device supposedly “zaps.” Like these devices, the maker of GAC promises vague “immune system boosts,” but with the added twist that he claims that all disease is due to original sin (along, apparently, with the conventional alt-med “toxins,” diminished qi, and uncharacterized immune dysfunction). Amusingly, the Monsignor who created this device also disses Hulda Clark and advocates the use of laetrile and Linus Pauling’s orthomolecular medicine. The main difference is that he claims to have received the design for the device from God through a dream.
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