I intensely dislike all forms of medical quackery. Of course, my passionate, full-throated, defense of the scientific consensus on the safety and effectiveness of vaccines is fairly obvious. There are literally mountains of evidence that support my skepticism of the antivaccine beliefs.
But there’s more junk medicine out there than the pseudoscience pushers running around the vaccine world. One of my favorite ones is homeopathy. It is a scam that tries to convince people that a vial of nothing more than water (and sometimes ethanol) has some magical medical properties. And it’s expensive water, much more expensive than some bottled water that claims it’s bottled at the source of some glacier in the Alps.
What is homeopathy?
But let’s back up a bit, and explain the “science” of homeopathy, because a lot of people, mostly Americans, conflate homeopathy with natural medicine, like herbal medicine. It isn’t. Basically, homeopathy, known as the “law of similars”, relies on belief that “let like be cured by like”, and is a term coined by Samuel Hahnemann, a German physician who was appalled by the state of medicine at the time, the late 1700’s. And frankly, the state of medicine at that time was pretty bad, so any new idea might have been worthy of trying. However, when Hanneman was alive, basic scientific knowledge was missing. Cell theory and germ theory were a few decades from even a basic understanding.
Homeopathic potions are prepared by serially diluting the original substance (could be anything from diseased tissue to arsenic to snake venom plus mercury) with shaking and forceful striking on an elastic body, which they term succussion. Each dilution followed by succussion is assumed to increase the effectiveness. Homeopaths call this process potentization. So far, it’s just merely diluting and shaking, so nothing much there. But the level of dilution is such that there is only a tiny possibility of any molecule of the original substance showing up in solution.
The dilution is precisely described by Hahnemann. The first dilution is one part to 99 parts water. Then, one part of that first dilution is then diluted in another 99 parts water. Each of these dilutions is called 1C, so two dilutions would be called 2C, with one part of the original similar diluted in approximately 10,000 parts water.
But it doesn’t stop there. Homeopathy uses >30C dilutions, which means that the final dilution is simply water with an almost 0% probability of including even 1 molecule of the original similar.
At 30C, the dilution is now 1 part substance to 10^60 (or 10 followed by 60 zeroes) parts water. You would need to drink 10^34 (or 10 followed by 34 zeroes) gallons of water (which is about 10 billion times the amount of water on earth) just to get one molecule–one single molecule of the original substance. Now diluting substances to create a physiological response is a well known, evidence based method in medicine. For example, allergy hyposensitization uses extremely diluted antigens (say cat dander), while slowly increasing the concentration to build a tolerance to the immune response. But the dilution is substantially higher, maybe 1-2C at most.
Maybe there’s some other mechanism for homeopathy?
Homeopaths overcome this mathematical issue by stating that water has a memory. This claim is based on a long-disputed, unrepeated, and basically, disregarded experiment.
Every attempt to repeat the experiment, in a double blinded manner, was a failure; so at some point, you have to say, “no it doesn’t work.” And of course, there is just no evidence that it might work. Just to be clear, there’s the clinical evidence that homeopathy absolutely doesn’t work:
The results of our meta-analysis are not compatible with the hypothesis that the clinical effects of homeopathy are completely due to placebo. However, we found insufficient evidence from these studies that homeopathy is clearly efficacious for any single clinical condition.
Is it even plausible that water has some memory? Remember, if one is going to make an extraordinary claim that water has some memory, then is it even imaginable under any circumstance? No, only if you reject all of the basic principles of quantum physics and chemistry. Water is one of the simplest molecules in the universe, and it has a very specific physical shape.
Furthermore, what magic would control water’s memory? Does that water remember being in toilet bowl? Or flushing out chemical tanks? The ridiculousness of thinking that water has memory is beyond simple words.
It is basically implausible (at almost the highest level possible) to imagine a water molecule, that can essentially form only one shape, “remember” an infinite number of molecules in the universe. Human memory, which isn’t all that well understood, is based on complex interactions of cells and proteins (and who knows what else), which can form an almost infinite number of complex structures.
Let’s ignore all that, maybe it still works.
OK, valid point (I’m conversing with myself here, but don’t judge). Water salesmen, I mean homeopathy proponents, like Dana Ullman cherry-picks data (often cherry-picking one sentence out of a negative paper), then trolls Twitter and Wikipedia (where he has been blocked and banned so many times, he must hold some record) with this cherry-picked data. It’s almost laughable.
Ignoring the water salesmen (let’s be honest, that’s what they are), the best data say that homeopathy is water – just water. A meta-analysis (which is the pinnacle of quality science) of over 225 medical studies and 1,800 peer-reviewed papers has found no evidence that homeopathy has any credible medical effect. Moreover, this study found 57 other systematic reviews of homeopathy that supported this conclusion.
In other words, homeopathy is the antithesis of science-based medicine. In fact, the authors state that “people who choose homeopathy may put their health at risk if they reject or delay treatments.”
This study was launched and supported by the National Health and Medical Research Council (NHMRC) of Australia, which is tasked to determine what are the best medical practices for its citizens. The NHMRC employed The Australasian Cochrane Centre, a division of the Cochrane Collaboration which specializes in publishing systematic reviews in medicine, to review and vet the meta analysis. This study should be considered one of the best to ever review homeopathy’s lack of clinical effect.
The committee that did the review included seven distinguished researchers, physicians and statisticians from across Australia. None had ties to pharmaceutical or nutraceutical companies for those of you who are inclined to conspiracy theories.
To be fair, a tiny number of the 1,800 papers reviewed showed some positive effects from homeopathy. However, careful analysis indicated that those “positive studies” had a small number of patients (larger numbers can eliminate bias and other statistical issues), were poorly designed (making it difficult to distinguish between positive and negative results), were carried out with poor oversight, or, the most condemning, were badly analyzed with misinterpreted results.
The NHMRC (and Cochrane) determined that these positive results were not sufficient evidence to reliably support a hypothesis that homeopathy has ANY clinical effect. In other words, it’s just water.
included in the study did describe research where homeopathy was claimed to be effective, analysis reveals that the studies had too few participants, were badly designed, were carried out with poor conduct, or were reported inaccurately. Either way, National Health and Medical Research Council reports that the seemingly positive results could not be used to reliably support the use of homeopathy.
In the meta review, the NHRMC researchers concluded that:
- There is no reliable evidence that homeopathy is effective for treating health conditions.
- Homeopathy should not be used to treat health conditions that are chronic, serious, or could become serious.
- People who choose homeopathy may put their health at risk if they reject or delay treatments for which there is good evidence for safety and effectiveness.
- People who are considering whether to use homeopathy should first get advice from a registered health practitioner. Those who use homeopathy should tell their health practitioner, and should keep taking any prescribed treatments.
This is a massive meta-review with significant depth and breadth of scientific research into homeopathy. And we can now conclude very clearly that homeopathy cannot cure anything but thirst, but at a great economic price. Moreover, though drinking this water may not harm you directly, if you choose it to treat real diseases (like Ebola), then you may harm yourself. Don’t do it. It’s just water.
- National Health and Medical Research Council. 2015. NHMRC Information Paper: Evidence on the effectiveness of homeopathy for treating health conditions (pdf). Canberra: National Health and Medical Research Council; 2015.