Homeopathy Does NOT Work On Babies or Animals!

Homeopaths have today been on the end of a mightily rigorous shoeing, courtesy of the House of Commons Science & Technology Committee here in the UK. Gimpy and DC have already posted excellent blow-by-blow accounts of the Committee's "Evidence Check" report, which dismisses homeopathy as pure placebo and denounces homeopaths for their slapdash and misleading attitude to the scientific evidence.

Predictably, the homeopaths have quickly started squealing about how unfair all this is. The BBC quotes Robert Wilson, of the British Association of Homeopathic Manufacturers, saying how "disappointed" he is:

He said the MPs had ignored evidence that homeopathy was effective. "There is good evidence that homeopathy works, for example in animals and babies, neither of which experience placebo effects."

I wish I had a pound for every time I have heard this pathetic argument. It is so obviously false that it immediately reveals that the speaker either has not thought for two seconds about what they are saying, or that they simply do not care that they are bullshitting. If you do not agree, pause for a moment before reading on, and see if you can think of any ways in which a placebo effect might work on a baby or animal.

Finished? OK, here is my list of possible mechanisms, in no particular order. If you have some different ones, or can explain why mine are wrong, let me know in the comments...

1. The effect is psychological, and operates upon the owner/parent. Because they expect the treatment to work, they see improvement where there is nothing, or nothing more than normal time-limited or cyclical changes in the condition. This effect is greatly enhanced when the owner/parent is highly motivated to see improvement, either because they have a strong personal belief in the treatment, or have invested time, money and credibility in it. It will also reassure the "worried well" parent/owner whose baby/animal is not actually ill in the first place.
2. The effect is real, but derives from changes in the parent/owner's behaviour and emotional state. Because they know their baby/animal is receiving treatment, they become less anxious. The babies/animals pick up on this mood change and so relax more themselves.
3. The effect is real but derives from changes associated with the treatment, rather than the treatment itself. For example, if the baby/animal has received extra care and attention, a change of diet or sleep patterns, and a break from work or other activities, these could have caused the improvement. Similarly, if an alternative treatment has been given in conjunction with real medicine, parents/owners may attribute any success to the treatment rather than the medicine.
4. The effect is real and arises as a conditioned response to the rituals of care. If the baby/animal has previously improved after taking real medicine, then the administration of a placebo in the same way can evoke the conditioned response.
5. The effect is real and arises as part of the acute phase response to an injury. Pain or inflammation evolved to stimulate the suffering organism to immobilise the injury site and to seek help. Once this has been achieved, the pain/inflammation is less necessary and can dissipate.

In other words,virtually all of the many factors that can influence the placebo effect in adults, can also produce placebo effects in babies/animals. Placebos DO have an effect upon babies and animals. Homeopathy does not.

The Science of Homeopathy

"I'm going to explain to you exactly actually how it works..."

You may have already seen this video when it first did the rounds a few months ago, giving everyone a good laugh. Now it seems that someone is trying to get it taken off the internet, with the entirely predictable result that hundreds of bloggers are now posting it all over again. Poor Dr Charlene Werner is rather embarrassed by all this attention. Good! This is as dense a pile of teh stoopid as you are ever likely to encounter! Enjoy...

Homeopathy Is Antiscience (Part 2)

"Who you gonna believe, me or your own eyes?" - Chico Marx

In the first post in this series I argued that homeopathy has a very low probability of effectiveness, because it ignores the Avogadro limit, it contradicts the dose-response relationship, and it uses "remedies" so ridiculous they are beyond satire. However, this does not mean that homeopathy is impossible: a low a priori probability could still, in theory, be nudged upwards by the accumulation of sufficiently convincing evidence. Using Bayesian mathematics, the probability can be recalculated after each study, giving a new prior probability for the next study which will be higher after a positive result and lower after a negative result. Eventually, given enough evidence, the prior probability could become high enough that even the most hardened sceptic would be forced to acknowledge the reality of the phenomenon. Think of Newton struggling with his theory of gravitation: he hated the idea of action at a distance, that one body could influence another instantaneously across empty space, yet the exquisite precision of his calculations gradually forced him to accept that it was indeed possible. So let's try to apply the same wisdom to homeopathy. Just how strong is the evidence?

The evidence for homeopathy can be grouped into four categories: in increasing order of credibility, these are individual reports, customer satisfaction surveys, experimental studies and meta-analyses. Of these, the first two are not generally considered very convincing, for several important reasons that will be explained. Let's start with individual reports...

Individual reports (aka anecdotes)

It is very easy to find individual accounts of the power of homeopathy. Pro-homeopathy sites are plastered with testimonials, such as this incredible story from classical homeopath George Vithoulkas:

A case in a coma for three months after an aorta transplant and a rejection process

The doctors became desperate.. ..the man had one or two days to live.. ..homeopathy could do something for the old man.. ..suspend all allopathic medication.. ..in seven days his consciousness returned and in twelve days from the beginning of the homeopathic treatment he asked us to take him home and we did.. ..one month later the man was so well that the only thing that was left was a swelling of his ankles.

Virtually every sceptical article attracts dozens of responses describing how homeopathy had miraculous effects for this or that illness, written by homeopaths and by homeopathy users. They range from the mundane to the incredible. Here's a mundane one that appeared this week on DC's Improbable Science:

My hayfever was so bad before I started taking pollen that I could at times be practically unconscious. I could never go for a walk in the park without first being dosed up with massive amounts anti-histamine. When I first bought the homeopathic remedy I knew nothing about medicine; I simply bought it because I was having an attack and couldn’t get any anti-histamine. I remember wondering how something that made me ill would make me better, but as I had no alternative I bought it and it helped.. .. I can now go out walking in the park now without any anti-histamine. I would definitely say that was a cure.

Here's another recent one, from a Guardian CIF thread:

I went to the Royal Homeopathic Hospital yesterday on referral from my GP. I've never been in a more welcoming and clean hospital. My God they actually had plants in pots there unlike the sterile NHS wars where any natural life is deemed a potential health hazard (by evidence-based standards of course).

I spoke to a homeopathic doctor (who was medically trained as well) and we went into the reasons why homeopathy is so attacked by the establishment. It's really sad to see that it is ignorance and big business conspiring, and they face a threat of having funding taken away.

I got more out of that visit than several visits to my GPs, who barely had time to speak to me and could only offer me a steroid spray or inhaler for my wheezing cough. They even tried to prevent me from my right to be referred to a homeopathist. They failed. Long may homeopathy and alternative healing that springs from a verifiable methodology continue.

People who post such stories seem genuinely surprised that their readers are not immediately converted to the homeopathic cause. To them, their experience feels so powerful that it trumps any scientific study: they simply "know" it works. They seem to regard any expression of scepticism as an accusation that they are lying, or as evidence that the sceptic is just part of a Big Pharma conspiracy (this attitude was beautifully spoofed in The Onion). In fact, most sceptics (myself included) are happy to accept that the vast majority of CAM users are genuine people who really believe their chosen therapies work. Even among practitioners there are probably many honest, kindly people: not every homeopath is a venal, lying con-artist.

The problem is this: there are many, many ways by which people can come to believe that a CAM treatment provides a benefit. Sceptics reject anecdotes simply because these other ways are all far more probable explanations for the benefit than the idea that improbable therapies like homeopathy actually work. It is worth spelling this out in detail because so many people fail to grasp this point. Let's have a look at the possibilities...

Why bogus therapies often seem to work

The list that follows is largely based on the late Barry Beyerstein's famous article Why Bogus Therapies Often Seem to Work, which everybody should read. My version adds a couple more points and unpacks the placebo effect to make 12 different explanations. If you can think of any more, please let me know and I will add them to the list.

1. The patient was not really ill in the first place. Many CAMs are simply providing reassurance for the worried well.



2. The illness was time-limited, so the patient would have recovered anyway. Colds, as the old joke has it, normally last a week, but with the right treatment can be cured in as little as seven days.



3. Because the patient has been feeling ill, they have taken time off work and cut down on their other activities. This rest has helped them recover.
   



4. The original diagnosis was wrong. The apparently intractable condition that has been "cured" was actually a less serious, time-limited illness.



5. The illness is episodic or cyclical, so if the patient usually takes their CAM when it is at its worst, the CAM will appear to work because of regression to the mean.



6. CAM therapists may encourage patients to change other lifestyle factors such as eating better, exercising more, sleeping more, drinking less and so on, and it may be these factors that make the difference.



7. Patients may take a range of treatments, including conventional ones, but attribute any improvement to the CAM. There is a nice example of this in John Diamond's book Snake Oil, in which a woman tells him that Gerson therapy has cured her cancer. On being pressed for more details, she admits that she has had chemotherapy too, but is convinced that it was the Gerson regime (carrot juice and coffee enemas) that made the difference.



8. Maybe talking to a therapist has improved their mood, so that they feel more positive about their condition. In this view, CAM is really just a branch of counselling. CAM consultations often last an hour or more, and involve talking about all aspects of the patient's life. It is not surprising that this can help people feel better.



9. There is an unconscious, conditioned placebo effect: they experience a learned response to the rituals of treatment. There is a good chapter on this in Barker Bausell's book Snake Oil Science, in which he describes experimental studies on animals and humans, showing that (for example) mice given repeated injections of an immunosuppressant continue to show the same suppression even after the injections are changed to a saline placebo.
   



10. There is an unconscious, evolved placebo effect. In Dylan Evans's book Placebo he argues that pain and inflammation after injury serve an adaptive purpose, to encourage us to immobilise the injury site, and to seek help. Once this "acute phase response" has done its job, the pain and inflammation are no longer needed and can decline.
    


11. There is a conscious placebo effect: they believe they will improve so they do. This effect of belief is what most people mean when they talk about "the placebo effect", and it is a wonderful thing that should be studied in more detail. Ben Goldacre's Bad Science explains that oval placebos work better than round ones, two placebos work better than one, coloured placebos work better than white ones, branded placebos work better than those in plain packaging and so on.
    



12. There is an investment effect: people who have given up time and money for a treatment are highly motivated for it to work, and so convince themselves that it has. The power of this effect is generally underappreciated, but is well-known to psychologists. For example, in this classic paper by Edward Desi, among students carrying out a tedious task for either a large reward or a small one, it was found that the ones getting the smaller reward reported having enjoyed the task more.
    

So when a sceptic dismisses an anecdote, they are not merely being stubborn or short-sighted. They are thinking about all these possibilities, comparing the probabilities, and applying Occam's Razor.

In the next post I will look at the next type of evidence: customer satisfaction surveys.

Placebo Needles for Acupuncture Research

The biggest problem with acupuncture research is that it is very difficult to create a convincing placebo treatment for the control group to undergo. If participants can tell whether they have received acupuncture or not, the results of the trial are pretty much worthless as evidence. Similarly, it is important that the practitioner too should be unable to tell whether they have given real acupuncture or not. Many different sham treatments have been tried, but none had been particularly convincing until, in recent years, some dummy needles have been developed that do allow double-blinding (Park et al, 2002, White et al 2003).

I wanted to see these needles for myself, so I contacted Dong Bang Acuprime, who kindly sent me a few samples of their Park Sham Device to try out. They have helped develop and test these fake needles in order to improve the evidence base for acupuncture, and I really admire them for doing so. Few CAM enthusiasts are willing to put their beliefs to the test like this.

So here I am with my colleague Nikola Bridges, who is about to insert two needles into the plastic sleeves you can see attached to my hands with sticky pads. One needle is real, one sham, but at this point neither of us know which is which. When Nikola presses down on the needles, the real one will penetrate my skin, while the sham one will slide inside its handle, giving the appearance of penetration without actually going in. If the placebo is truly convincing, neither of us will be able to tell which is which until I turn my hands over, at which point the fake will fall out onto the table.

To see what happened next, watch this video before scrolling down to read on...

All in all, I was a little disappointed. The fake needle telescoped very easily while the real one took a lot of tapping to get down to the same extent, so it was fairly clear to Nikola which one was real. I couldn't feel much difference at first, after the initial insertion, but it was pretty obvious which one was real once it started to go in properly. The real needle also left a tiny but noticeable mark on my skin, and was obviously longer than the fake one when we took them out again. There is also still (a few hours later) a hint of pain in my left hand. Sadly, I have to conclude that the placebo was not 100% convincing.

Let's not be too negative, however. There were many flaws with my little experiment. In a real study, you would not have the same person experiencing both types of needle at the same time, so the contrast between needles would not be so apparent. If the acupoints were out of sight, such as on the patient's back, it would be harder (for the patient, at least) to tell what was going on. I am not sure if it is important that Nikola is NOT an acupuncturist and had not had any chance to practice the insertions (she is a neuroscientist and has plenty of experience with needles, just not this kind) but I think it would probably be even more obvious to an experienced needler which one was which. We were both a bit nervous, though! Maybe two single confident thrusts might have been harder to discriminate?

My conclusion is that it is very hard to maintain double-blindness in acupuncture studies, even with the best sham needles. I think it may be possible to do a good double-blind study with these, but both patient and practitioner would have to be very self-disciplined, to resist the temptation to break the blinding. Sadly, my experience suggests that it would be very easy to succumb.

References

Park, J., White, A., Stevinson, C., Ernst, E. & James, M. (2002). Validating a new non-penetrating sham acupuncture device: two randomised controlled trials. Acupuncture In Medicine, 20, 168-174.

White, P., Lewith, G., Hopwood, V. & Prescott, P. (2003). The placebo needle, is it a valid and convincing placebo for use in acupuncture trials? A randomised, single-blind, cross-over pilot trial. Pain, 106, 401–409.

Homeopathy Is Antiscience (Part 1)

Homeopathy is simply an elaborate placebo. It is certainly not scientific, but it is worse than mere non-science: it is anti-science, and so should have no place in a University. In this series of posts I will explain why. In the first instalment I will describe the dilution problem, and the bizarre range of substances that homeopaths claim to have medicinal properties. In later posts I will consider the research evidence and evaluate the counterarguments that homeopaths use against their critics. But let's start with the basics...

The Dilution Problem

The probability that a homeopathic substance could have any effect (other than placebo) is vanishingly small. We can say this with some confidence because homeopathy contradicts at least two of the most solidly-established principles in biology and chemistry. The first is that larger amounts of a drug or toxin have larger effects. This is called the dose-response relationship, and it is an iron law of biomedicine. Ten paracetomols are more dangerous than two, just as ten pints of ale will get you drunker than two. There are no exceptions, except in the topsy-turvy world of the homeopath, where lower dilutions such as 3X can be bought over the counter and given to babies (e.g. for teething) whereas extremely high dilutions such as 200C are thought to be far too dangerous for this, and should only be prescribed by a trained practitioner.

For readers unfamiliar with homeopathic notation I will explain these dilutions. The "X" means that the original essence has been diluted one part in ten, and the number tells you how many times the dilution has been repeated. So 3X means that a one in ten dilution has been repeated three times, leaving a final concentration of one in a thousand, or 1x10E3. A "C" dilution is one in a hundred, so a 200C preparation would have a concentration of one in 1x10E400 (forgive me for not writing out the full number: a one followed by 400 zeroes). This brings me to the second basic principle that homeopathy flaunts: the Avogadro limit. Once the dilution process has passed 24X or 12C we can be pretty sure that no molecules of the original substance remain. According to the standard molecular model of Chemistry it is impossible for these dilutions to have any effect. At the lower dilutions yes, a 3X dilution will still contain a fair dose of the original essence, but most homeopathic preparations are taken way beyond the Avogadro limit: 30X and 30C are probably the most commonly used. To visualise a 30C dilution, imagine one molecule of an active ingredient being added to 10E60 molecules of diluent. What would this look like? We are not talking drop-in-a-swimming-pool or even drop-in-the-ocean here. 10E60 water molecules would make a sphere twenty-eight billion times larger than planet Earth.

Homeopaths are aware of the dilution problem, of course. However, they contend that it is irrelevant because of the way the dilutions are carried out. Between each step in the dilution process, the preparation is vigorously shaken (or "succussed") in order to transfer the "healing energies" of the solute into the diluent. This is obvious nonsense, and we will see later on that there is absolutely no evidence that succussion has any effect. But first, let's look in more detail at the range of substances homeopaths use to create these strange solutions.

Animal, Vegetable, Mineral?

At dilution levels beyond the Avogadro limit it makes no difference what the original essence was, but it is still worth spending a few moments considering the range of ingredients that homeopaths use. This provides another reason to be sceptical about the claims of homeopathy: the jaw-dropping silliness of the so-called remedies.

One common misconception about homeopathy is that it uses only natural substances, such as herbal essences and plant products like coffee or onions. Indeed, there are homeopaths who choose to specialise in such remedies, but for most practitioners the herbals are only a small part of their armoury. Another very important group of remedies are based on minerals, especially salts such as sodium chloride, magnesium phosphate and silicon dioxide, which you can buy in combination as a hayfever remedy. A third group of remedies are based on animal parts or products, such as duck liver, snake venom and even dog excrement. Fourthly, there are remedies known as “nosodes”, which are made from human disease products, such as pus, mucus, blood, faeces and scraps of tissue. Finally, there is a group of remedies known as “imponderables”, made from such things as electricity, thunderstorms or sunlight. There is even a remedy made from fragments of the Berlin Wall, used for those who feel oppressed, or who find themselves having to mediate between warring factions. I am not joking: homeopath Charles Wansbrough reports using Berlin Wall for patients who have “decided that their surrounding environment was hostile and suppressive and chose to create a ‘wall’ of fury that encircled their way of being”. Kees Dam was sceptical but decided to try a proving and was convinced:

“My ‘Berlin Wall’ was broken down when I trusted and believed my eyes seeing the effects of Berlin Wall as a homeopathic remedy”.

Dam admits that the proving was not done blind, but does not think that to be a problem:

“I must honestly say that I never saw any difference in the quality of the proving depending on if the prover knew the remedy or not”.

I hope it is clear that such thinking is closer to sympathetic magic or voodoo than it is to science. Some homeopaths agree, and remedies like Berlin Wall have proved divisive. George Vithoulkas launched a stinging attack in a speech in, appropriately, Berlin:

“If we teach our students to do or apply ridiculous things we will only reach the 'ridiculous', if we potentize the Berlin wall, or the National Anthem of France and we encourage our students to follow such nonsensical ideas, homeopathy will be identified with the ridiculous.”

Quite.

Homeopaths select these "remedies" according to a principle known as the “Law of Similars”, or “Like cures like”. In 1790, the German physician Samuel Hahnemann noticed that cinchona bark, which contains quinine and had long been used as a malaria remedy, actually produced some of the symptoms of malaria when taken by a healthy person (namely himself). Unfortunately for homeopaths, it may be that Hahnemann’s reaction to the cinchona was in fact simply the result of an undiagnosed allergy. Nevertheless, it led him to wonder if a general principle of similarity could be used to discover new remedies, and to classify the chaotic muddle of herbal and mineral preparations that constituted the materia medica of the day. He therefore embarked on a series of experiments upon himself and others, to test for the pathological effects of various substances, including mercury, belladonna, tobacco and nux vomica. Family, friends, students and colleagues submitted themselves to these “provings”, and by 1796 he was convinced that homeopathy (“similar suffering”) was indeed the answer: a substance that causes particular symptoms in a healthy person can be used to cure those symptoms in a sick person. A few examples of the current uses of well-known substances should suffice to give the general idea: onions irritate the eyes and nose, and so may be given as a treatment for colds; coffee is a stimulant, and so can be used to treat insomnia; arsenic causes sickness and diarrhoea, and so is used for food poisoning, and so on.

Hahnemann intended his work on similars to be a refutation of the doctrine of signatures, which provided the basis for much of the medicine of the time. For Hahnemann, similarity was solely a matter of the effects a substance had, not (as in the doctrine of signatures) anything to do with its physical appearance or provenance. However, it is immediately clear from considering the range of substances described above that the doctrine of signatures quickly re-asserted itself, and that a major flaw in the method used in Hahnemann’s provings allowed this to happen (and has been perpetuated in almost all subsequent provings by others): his experiments were not done blind. In other words, he always knew exactly what his guinea pigs were taking, and probably they knew it too, and so his and their perceptions of any symptoms would inevitably have been coloured by the nature of the test and their existing knowledge of the substance. It is not therefore surprising that many ancient herbals resurfaced in homeopathy with similar functions based on appearance. Euphrasia, for example, re-appears as a homeopathic remedy for eye problems, just as it did under the doctrine of signatures owing to its supposed resemblance to a bloodshot eye. So as we have seen, nowadays virtually anything can be (and is) used as a homeopathic remedy, often based on nothing more that superficial resemblances or associations.

Conclusion

In this post I have explained three reasons to be highly sceptical of homeopathy: it defies the dose-response relationship, it ignores the Avogadro limit, and it uses a bizarre range of ingredients. Despite this, many homeopaths claim that there is good evidence that homeopathy does work. In the next instalment I will consider this evidence in more detail.