Astin1 accuses critics of complementary and alternative medicine (CAM) of ignoring the evidence. He has provided a few relatively uncontroversial examples of treatments for which there is some published evidence, implying that this can justify the rest of CAM. However, he does not mention the far greater number of CAM treatments that clash with well-established scientific principles and for which there is no believable evidence. Where, for example, is the evidence for high colonics, Laetrile, chiropractic asthma cures, bee pollen therapy, iridology, applied kinesiology, ear-candling, whole blood analysis, radiesthesia? As for the evidence cited for healing through prayer and therapeutic touch, readers should also know that there have been both cogent methodologic critiques of this work and also failures to replicate these findings in better-controlled studies.2 Meta-analysis will not suffice here, because it cannot compensate for the shortcomings of the studies that went into the analysis. Rigorous methodologic standards, not prejudices, account for why critics are not as impressed with the evidence for CAM as Astin, Sierpina, and Philips3 think they ought to be.
The main thrust of my March 2001 article4 was that research with subjective endpoints and inadequate controls for the biases that I enumerated counts for very little. For instance, my colleagues use many of the homeopathy studies Astin mentions to teach students how to spot methodologic flaws in experiments. Likewise, Astin presumably chose the example of St. John's wort because it is among the best-supported CAM treatments, but the methods of the earlier studies—typically fed into meta-analyses such as those he cited—have been strongly criticized.5 Later studies with better controls for the sources of error outlined in my paper found the effect largely dissipated.6,7
Regarding the defense of Andrew Weil by Sierpina and Philips, I wonder whether they wish to defend Weil's advocacy of “stoned thinking” as a way of deriving medical facts, as cited in my article. As for Herbert Benson, I am not alone (see citations in my article) in finding many of his pronouncements to be insufficiently supported by research.
Astin chides me for not citing research to support my assertion that CAM is largely ideologically driven. In response to editorial requests to shorten my manuscript, I did unfortunately have to omit these citations. Far from being unaware of the excellent work of Adrian Furnham, however, I have a student whose thesis is an extension of Furnham's work. Furnham also contributed to a book I co-edited some time ago. Furnham's work is consistent with my picture of the beliefs and attitudes that underlie CAM. Indeed, I could also have cited Astin's own 1998 paper8 in support of my position. Therein, he concludes that his respondents endorsed alternative medicine “largely because they find [it] to be more congruent with their own values, beliefs, and philosophical orientations toward health and life” and that alternative therapies were often adopted following some kind of “transformational” spiritual experience. That world view, as I asserted, includes strong subjectivist, animistic, and vitalistic elements. Also supporting the assertion that CAM's adherents are attracted by its magical orientation, I could have cited Siahpush,9 who found that holding a “set of postmodern values” was the best predictor of adherence to CAM. Among these values listed in Siahpush's references are extreme relativism, distaste for technology, naive belief in the beneficence of nature, and a variety of antiscientific beliefs.
Astin asserts that reluctance to accept alternative therapies because they are based on putative mechanisms contradicted by much scientific research amounts to irrational bias. He seems to forget that the burden of proof is on the claimant and that the claims of CAM qualify as “exceptional claims.” Thus, it is reasonable to demand exceptional amounts and quality of evidence. If there are hundreds of studies supporting a conventional model and a scant handful of methodologically debatable ones supporting a proposed alternative, it is hardly mere prejudice to retain one's belief in the original model. This is as it ought to be until the quality of the new studies is at least as good as the best of the original ones and the proponents of the new model can put forward convincing explanations for how the conclusions drawn from the original corpus could be based on a misunderstanding of the original data. Otherwise, the balance of probabilities still strongly favors the currently accepted model.
As for Astin's defense of clinical judgment, I would refer readers once again to the work of Robyn Dawes (and other researchers cited in my paper), which emphasizes how that kind of informal judgment frequently leads to erroneous conclusions about efficacy. That, after all, was the main point of my paper.
Astin accuses critics of CAM of being unwilling to change their beliefs when confronted with evidence. In fact, scientific biomedicine changes its mind frequently, based on new evidence. It, unlike CAM, has abandoned many treatments that subsequently turned out to have been accepted due to the kinds of erroneous reasoning outlined in my paper. It is proponents of CAM who practically never engage in this kind of housecleaning. Testimonials are a place to start in developing objectively testable hypotheses. They count for very little in and of themselves or we would still be bleeding and purging patients for a variety of diseases.
1. Astin JA. Complementary and alternative medicine and the need for “evidence-based” criticism. Acad Med. 2002;77:864–8.
2. Scheiber B, Selby C (eds). Therapeutic Touch. Amherst, NY: Prometheus Books, 2000.
3. Sierpina VS, Philips B. Need for scholarly, objective inquiry into alternative therapies. Acad Med. 2001;76:863–4.
4. Beyerstein BL. Alternative medicine and common errors of reasoning. Acad Med. 2001;76:230–7.
5. Field HL, Monti DT, Greeson JM, Kunkel EJS. St. John's wort. Int J Psychiatr Med. 2000;30:203–19.
6. Shelton RC, Keller MB, Gelenberg A, et al. Effectiveness of St. John's wort in major depression—a randomized controlled trial. JAMA. 2001;285:1978–86.
7. Hypericum Depression Trial Study Group. Effect of Hypericum perforatum
(St. John's wort) in major depressive disorder: a randomized, controlled trial. JAMA. 2002;287:1807–14.
8. Astin JA. Why patients use alternative medicine. JAMA. 1998;279:1548–53.
9. Siahpush, M. Postmodern values, dissatisfaction with conventional medicine and popularity of alternative therapies. J Sociology. 1998;34:58–70.