Apr 16 2009
The Cochrane Collaboration, an organization dedicated to evidence-based medicine, has published a review of studies of homeopathic treatments for side effects of radiation therapy and chemotherapy for cancer. The results are unimpressive – consistent with the null-hypothesis that homeopathic remedies have no effect. And yet the review is being distorted to promote a very misleading bottom-line to the press – that homeopathic remedies have a role to play in cancer therapy.
One point has been made clear – the treatments under study are not for cancer itself, but for the side effects of standard cancer therapies: radiation and chemotherapy. However, the results are being presented as if they support the efficacy of homeopathic remedies, when they do not.
Some quick background on homeopathy: This is a pre-scientific philosophy of medicine invented by Samuel Hahnemann around 1792. The principles of homeopathy are akin to sympathetic magical rituals. They include the notion that like cures like, or that a small amount of a substance that causes a symptom can be used to cure it. However, he then combined this principle with his “law of infinitessimals” which states that substances will become more potent as they are diluted, even if they are diluted beyond there point where any active ingredient remains. And finally he came up with the notion of succussion – that homeopathic remedies are given their power by shaking them 10 times in each spacial plane.
There, of course, are many more details to discuss, but that is the bottom line. There is no scientific basis to any of the ideas of homeopathy. This nonsense was rightly ridiculed in its day, but it has somehow survived in the culture, especially in Europe. It has made somewhat of a resurgence, riding the coattails of the broader CAM movement, but there may be signs recently that it is once again waning.
Two centuries of science after Hahnemann has not only failed to validate any of his principles, but has moved even farther away. Modern homeopaths now appeal to the notion that water can somehow have “memory” of the chemicals (but only the desired ones) that were previously diluted in it, and that this memory can survive the preparation of the homeopathic remedy, storage, later ingestion, absorption into the blood and tissues, transportation to its active site (whatever that is) and still retain its properties to have some physiological effect on the body. This is beyond fanciful, beyond science fiction – it is pure fantasy.
If that were not enough, clinical trials of the efficacy of homeopathy have been essentially negative (when looked at as a body of evidence). We see the typical distribution of results for ineffective treatments – a scattering of positive and negative, with a clear trend that the better designed a study the more likely it is to be negative. There is also the absence of replicability. To date no one has been able to establish with high quality replicable studies that any homeopathic remedy has any effect.
The review looked at 8 clinical trials:
Eight controlled trials (seven placebo controlled and one trial against an active treatment) with a total of 664 participants met the inclusion criteria. Three studied adverse effects of radiotherapy, three studied adverse effects of chemotherapy and two studied menopausal symptoms associated with breast cancer treatment.
So really this is three separate reviews, two of three trials, and one of two trials. Those are extremely small numbers of trials to review, and perhaps that is why they were combined into one publication. Even 8 trials is a small number, and only three of the studies were considered of high quality. That’s slim pickings.
The results overall reveal that four studies were negative and four were positive. This is the kind of distribution we expect for treatments that have no physiological effect.
Here are the author’s conclusions:
This review found preliminary data in support of the efficacy of topical calendula for prophylaxis of acute dermatitis during radiotherapy and Traumeel S mouthwash in the treatment of chemotherapy-induced stomatitis. These trials need replicating. There is no convincing evidence for the efficacy of homeopathic medicines for other adverse effects of cancer treatments. Further research is required.
Given the slight data, this is not, in my opinion, a responsible characterization of the results. For other (non-CAM) questions Cochrane reviews, in my experience, would more likely simply say that there is insufficient data to draw any conclusions – not that there is preliminary data to support efficacy.
The notion that further research is required is also problematic. This is true in that the data available so far (with regard to these specific indications) is very slim. However it assumes that the clinical question is reasonable, when it isn’t. Homeopathy is without prior plausibility, and therefore one could argue that it does not deserve any research. Further, homeopathy overall has already been studied sufficiently to conclude on empirical grounds alone that it is without efficacy.
There are endless specific indications that could be studied and if you focus only on the specific indication we could be in an endless cycle of studying various homeopathic preparations for numerous indications. In fact, we are in this endless cycle. Frankly it is long past time that we should get off this treadmill and conclude that homeopathy as a scientific notion is dead and should be discarded.
But the homeopathy industry thrives on the phrase – “more research is needed.”
Further, many of the press reports of this review declare Homeopathic Meds Can Coexist With Conventional Cancer Treatment, or something to that effect. They are referring to the fact that the review found few side effects from the homeopathic remedies. I acknowledge that truly homeopathic remedies have no direct side effects – because they have no effects.
By that reasoning tap water is also compatible with conventional cancer treatment. This is an extremely misleading headline as it makes it seem as if there is some utility to combining homeopathic treatments with conventional cancer treatment, but even this friendly review did not show that.
You Got Drugs In My CAM
I also have not yet discussed the most deceptive aspect of this review. When interviewed for the BBC about this review, Edzard Ernst, professor of complementary medicine at the Peninsula Medical School, said:
Second, nobody doubts that undiluted remedies can have effects; and interestingly, the positive studies here seem to be on such medicines rather than on the highly diluted treatments which are a hallmark of homeopathy.
In fact, the calendula cream found to be effective in one study is not diluted at all and thus it cannot, to all intents and purposes, be considered to be a typical homeopathic remedy.
That is what we euphemistically call “cheating.” It is highly misleading to include a study of an undiluted herbal drug and call it homeopathy. This was the single most positive study in the review, and it wasn’t even a study of true homeopathy.
This is a broader problem in CAM treatment and research. For example, studies are often promoted as showing that acupuncture works, when in fact they are not studies of acupuncture but of electrical stimulation through acupuncture needles. This says nothing about the principles of acupuncture, or whether or not sticking needles in the skin does anything physiological. It only confirms what we already know, that electrical stimulation can have certain effects, including pain relief.
Likewise homeopathic and even herbal remedies are sometimes adulterated with actual pharmaceuticals. (See here, and here.) Most clinical trials of these products do not do purity testing to eliminate the potential for adulteration to affect the outcome of the study.
In this case the product was not adulterated with a drug, it was a drug and was just mischaracterized as “homeopathy.”
Evidence-Based vs Science-Based Medicine
The bigger issue here is what I and others perceive to be a critical flaw in the concept of evidence-based medicine (EBM) embodies in the Cochrane Collaboration. In practice they focus on clinical evidence almost to the exclusion of scientific plausibility (which, I should add, is itself based upon evidence). This was done specifically to level the playing field, so that treatments and practices that made sense were not given a pass on the evidence. Even treatments that make scientific sense and seem to work need to have evidence to back them up, because they could still be wrong, as history clearly indicates.
While I agree with this, they neglected to consider the other side of the coin – what about treatments that are extremely scientifically implausible. My guess is that EBM innovators simply did not consider this. They assumed (and this is not a bad assumption, it just came at the wrong historical time) that treatments under consideration would make some scientific sense. We’re talking about medicine not witchcraft, right?
But then along came alternative medicine, which is witchcraft desperately trying to conceal itself in the garb of modern medicine. By leveling the playing field EBM also gave a leg up to therapies with extreme scientific and biological implausibility.
And that is how we end up with a homeopath leading a Cochrane review of homeopathic remedies (i.e. water) and writing a distorted review that is spun to the press that homeopathic is useful when it isn’t.
This is also precisely why we need to replace EBM with SBM (science-based medicine). Prior plausibility needs to be factored back into the scientific process of evaluating potential medical modalities and claims.
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