This week in under the microscope, we examine one of my favourite pseudosciences; homeopathy.
The practice of homeopathy first arose in the early 1800’s with the publication of ‘The Organon Medicine’ by Samuel Hahnemann.(1) The medical practices of the time were centred on bloodletting and administering poisonous antidotes designed to balance the four humours, often doing more harm than good.
Hahnemann sought a ‘better’ way to treat patients and in doing so devised homeopathy. Hahnemann’s theory was that a disease could be treated with a substance that in healthy people would cause the same symptoms as the ailment you were trying to treat. This is known as like cures like or the ‘law of similars’. He also believed that dilution and vigorous agitation would make a remedy more potent, the ‘law of infinitesimals’. Taking these kinds of remedies was supposed to balance your vital force and thus make you healthy.
Homeopathic remedies would be prepared by starting with an ingredient (for instance a herbal extract) and diluting this 1:10 or 1:100 and vigorously shaking (known as succussion). This solution is then diluted again by the same factor and the process repeats maybe up to 60 times. At that kind of dilution one would have to consume more than all of the Earth’s oceans just to receive a single molecule of the active ingredient that is supposed to have an effect. In fact you are more likely consume molecules of human faeces then you are the substance that was originally added to the first dilution.
If you want a more fathomable way to comprehend the dilution involved try a simple kitchen experiment. Start with 10ml of cordial and add it to 90ml of water, then add 10 ml of this solution to 90ml of water. Repeat this process until you have diluted the original sample ten times, known as 10x in homeopathy terms, what does the final solution taste like?
How then if homeopathic remedies contain no active ingredient might they actually work? The original ideas of how dilute amounts of substance could have an effect on the body was based on the ideas of dynamization which in turn relied on Hahnemann’s own suppositions which weren’t based on any specific observations.
Modern proponents of homeopathy have proposed that water has a memory of what was previously dissolved in it, although they offer no explanation of why water can retain the memory of some molecule and not others, for instance the aforementioned faeces. One study, published 1988 in Nature, one of science’s most prestigious journals, seemed to prove water memory. The study headed by Jacques Benveniste, at the time a respected scientist, found that human basophils reacted to homeopathic antibody solutions in the same manner in which they would activate when encountering the actual antibody(2), however John Maddox the editor of Nature at the time was critical of the results and formed a team including Walter Stewart and esteemed skeptic James Randi to try and replicate the results. When a double blinded protocol was enacted they could not replicate the results and the original findings were attributed to experimenter bias.
So what does the science say? There are a few trials that show some effect above that of a placebo however these are mostly carried out by researchers with conflicts of interest or studies which employed poor methodologies, often reported in homeopathic journals. A major review of the best placebo controlled double blinded studies has shown no significant effect than that of an equivalent placebo.(3)
Some homeopaths have suggested that homeopathy cannot be tested by empirical methods, not only is this a logical fallacy called special pleading but it’s also a post-hoc rationalisation i.e. making an excuse after the fact. This kind of denial of negative evidence also constitutes a certain amount of hypocrisy or selective thinking because many homeopathic practitioners are quick to champion the few positive studies on their promotional materials.
If homeopathy doesn’t work why are people still using it over 200 years later? This is a complicated question involving complex human psychology. The most simple answer is; because they want it to work. Homeopathy is a quick and painless solution compared to modern medicine in the eyes of a lot of people. In fact in some cases, homeopathy appears to provide a “treatment” where modern medicine only provides a sit and wait approach, for instance conditions like the common cold. In this modern age people feel like they should be given some kind of medicine for their problem, they don’t want to be told to “stick it out” or participate in a sometimes lengthy treatment regime.
Connected to this is a patient’s need for contact and reassurance. Many homeopathic remedies treat minor maladies that are facilitated by stress. GPs and other physicians don’t have a lot of time to spend with each patient, homeopaths however may spend upwards of forty minutes with patients, assessing all their symptoms, consulting impressive looking texts books to find the “best” remedy and dilution factor. This process alone can often lead to the alleviation of stress related symptoms in these kinds of patients.
You also have to consider what types of patients are seeking the help of a homeopath. Quite often the kind of complaints for which one would seek alternative medicine are called self limiting diseases, infections or pains that would eventually resolve themselves given time. This is where people make a common logical fallacy called post hoc ergo procter hoc, which means, it happened afterwards therefore it happened because of. Many people take a homeopathic remedy, and because their disease is self limiting some time after taking the remedy the illness resolves. Patients incorrectly attribute the resolution to the homeopathic remedy when in fact the disease progressed naturally and eventually went away using the body’s own mechanisms. These kinds of events serve to positively reinforce in the patients mind that homeopathy works and makes them more likely to seek a homeopathic treatment next time they have an illness.
Finally many people are unaware of what homeopathy actually is. They may believe that homeopathic remedies are actually herbal remedies which have a much more plausible chance of actually having an effect. These kinds of naturalistic alternatives carry big weight with those that are suspicious of evidence based medicine and the motives of “big pharma”.
You may ask then what the harm is in people taking homeopathic remedies if they are just water with no plausible way of having an effect of any kind on the body. One homeopath recently pointed out; “…during the last five years just 21 people have had side effects from homeopathic medicine with no fatalities…”. You can’t deny that this sounds very impressive, but it’s not surprising when you consider there is no scientifically known mechanism by which homeopathy could have any effect at all, let alone so called “side-effects”.
The remedies themselves then are innocuous, the harm comes when sick and sometimes desperate people turn their back on evidence based medicine in favour of alternative modalities, in this case homeopathy. Just recently there was a case reported in the press in which a four year old child dies from a simple cold like pneumonia because his parents opted to treat him with a homeopathic fennel tea remedy instead of seeing their local GP. By the time the boy presented to ER the damage had already been done and unfortunately he later died.
This is an extreme case of course; many people have more mundane ailments that could have been cured much quicker with modern medicine. But whether someone opts to treat their cancer with homeopathy or a simple infection or cold they are not getting the best possible care and that is where the harm lies.
Remember, when considering a treatment with no plausible mechanism of action and claims that seem to convenient or too good to be true, think critically about it and ask your doctor or pharmacist for advice before coming to any conclusions about your health care.
1 – S. Hahnemann, Organon of Medicine, 1842, http://books.google.com.au/books?id=n3YC435gKFIC&lpg=PP1&dq=The%20Organon%20of%20Medicine&pg=PP1#v=onepage&q=The%20Organon%20of%20Medicine&f=false
2 – E. Davenas, F. Beauvais, J. Amara, et al., Human basophil degranulation triggered by very dilute antiserum against IgE, Nature, 6176  <816-818>, (1988)
3 – T. Hines, Pseudoscience and the paranormal, Prometheus Books, 2003, <360-362>, http://www.amazon.com/Pseudoscience-and-the-Paranormal-ebook/dp/B003UD7RMS
4 – Homeopathy, Skeptics Dictionary, 13/08/2011, http://www.skepdic.com/homeo.html