Dear Dr. Novella,
Once again I have to agree with some of your premises, but disagree with your misguided leaps of illogic. I agree that if a modality has not been proven effective, the only way it should be left alone to be used by the public is if it has been shown to be safe. Alas, the risk-benefit equation is an individual choice, and we cannot impose our quantitative bottom line on it. Your assertion that scientific medicine is being eschewed because of acceptance of alternative modalities is as flawed as maintaining that a rain dance brings on rain. I know you said the relationship was complicated, but let's be honest: you think that CAM acceptance is killing allopathic medicine.
Now, let's get on to "proof" in science-based medicine. As you well know, while we do have evidence for efficacy and safety of some modalities, many are grandfathered without any science. Even those that are shown to have acceptable efficacy and safety profiles as mandated by the FDA, are arguably (and many do argue) not all that. There is an important concept in clinical science of heterogeneous response to treatment, HTE, which I have addressed extensively on my blog. I did not make it up, it is very real, and it is this phenomenon that makes it difficult to predict how an individual will respond to a particular intervention. This confounds much of what we think is God's own word on what is supposed to work in allopathic medicine.
Finally, do you really think that agents that are approved based on a 2-week prolongation of median survival in a desperately ill population of patients are used because of their supposed scientific merit? I would have to argue that there is a lot of subcortical emotional thinking that goes into these decisions. Can you really prove to me that a 2-week increase in median survival is not tantamount to placebo effect, aka type I error? Yet this is science-based. I think if I had a horrible disease, I might opt for acupuncture to make me feel better in the weeks I have left rather than rely on this kind of "science" to prolong my misery by 2 weeks.
Bottom line, we need to appreciate that none of the science is all that straightforward. Let us not dumb down the arguments and create false dichotomies. If we do, no one wins.