Earlier this month, the heroic charity Sense About Science announced some disturbing results from a study they had carried out. Selecting ten homeopathic clinics at random, they sent an intern to each of them to enquire about protection from tropical diseases. Every single clinic, it turned out, was prepared to prescribe homeopathic pills for not just malaria, but typhoid, dengue fever and yellow fever. Not one of the homeopathic practitioners involved mentioned that homeopathy is meant to be a complementary, rather than a replacement, medicine, nor did they recommend that the patient consult an actual doctor before she went off on her tropical holiday.
"They make it so your energy doesn't have a malarial-shaped hole in it," said one practitioner, of the dosages she was supplying, "so the malarial mosquitoes won't come along and fill that in." Say what?
So whether or not your body is invaded by the blood-borne parasite Plasmodium falciparum depends on whether your "energy" has a hole in it? Energy has holes? Mosquitoes can tell? The mozzies are flying about going "oh, that one's got his energy holes filled in; I'd better go and bite someone else"?
This has been worrying me all week. Are humans really so daft? And finally, the answer came to me, like a gift from the Magic Pixies: people believe in homeopathy, and are prepared to expose themselves to grim tropical diseases armed with only a few drops of 30X diluted arnica, because they have never found out that homeopathy and herbalism are not the same thing.
Herbalism, in its essence, is the father and mother of all modern medicine (well, maybe not surgery) and is the parent skill, ultimately, of chemistry. It employs active ingredients. Many herbal remedies (not all of them though) do work, and there's plenty of good, solid, empirically tested evidence to show that they do. There can be problems with blind reliance on herbalists, of course, not the least of which is that mixing them with other sorts of medicine without taking medical advice, can land you in hospital, but that's not the issue here.
The issue is that homeopathy is not herbalism. And the most important thing to know about homeopathic remedies is that they don't contain any active ingredients at all beyond what's in the water used to dilute them.
Like much other pseudoscience, there is a grain of truth at the very bottom of homeopathic theory, and it's this which is used to blind its adherents into believing in it. Homeopathy has taken Edward Jenner's 1796 cowpox vaccinations for smallpox - the beginning of the entire science of immunology - and turned it into mumbo-jumbo of the most bizarre sort.
Samuel Hahnemann, the progenitor of homeopathy, claimed that inducing a low level of a condition in the patient could confer immunity. Where it differs from immunology, though, is that Hahnemann claimed that inorganic compounds could produce the same effects as organic ones, and the smaller a dosage, the greater its effect. You can't be too cross with Hahnemann, who published his initial treatise on the subject in 1810: he was, after all, practicing in an era when bloodletting was regarded as effective medical practice, and his intention was certainly to move medicine away from the violent and frequently deleterious practices on which it relied. But if you actually take a look at how homeopathic dilution is done, the only way that a bottle of your favorite tincture will actually contain even one molecule of the substance on the label is by accident.
Homeopathy works like this: you take one part of the substance in question - let's say, as we're discussing malaria, quinine, which was the standard preventative treatment at the time Hahnemann and Jenner were working. You then dilute it by shaking it up with 9 parts water. A 1-9 ratio is known as a 1X solution. You then throw away 9/10ths of the solution and repeat the dilution using the same ratio, producing a 2X solution. This procedure is repeated until the desired dilution is achieved. Most homeopathic medicines come in strengths between 6X and 30X, though far, far weaker solutions have been used.
But, look. The way math works, if you carry on like this to, say, a dilution level of 30X, the original substance will now form 1 part in 1,000,000,000,000,000,000,000,000,000,000. Yup, that's not a misprint. Now, let's put that number in perspective. If a container at that dilution were to contain a single molecule of the original substance, that container would have to be more than 30,000,000,000 times the size of the Earth.
Homeopathy relies on an idea called the "law of infinitesimals", which says that any water that has had contact with water that's had contact with water that's had contact with a substance will contain an "essence" or "memory" of that substance. Mmmm. But given the finite amount of water on Earth and the amount of time it's been around, that also means that your homeopathic medicine will also contain Essence of Pretty Much Everything, including dead pirate, toxic waste, goldfish feces and 9/10ths of every 1X dilution that's ever been thrown down a drain. How come those ingredients don't have some sort of effect? Because your practitioner says so? It's not, well, very scientific, is it?
Yes, yes, but... science doesn't know everything, does it? And just because there's been double-blind trials (where a drug is tested against a placebo and neither tester nor test subject knows which is which) that have shown homeopathy to be ineffective, that doesn't mean that there's not loads of anecdotal evidence that it works. Everyone knows someone who knows someone whose intractable allergies vanished when they tried homeopathy, don't they?
Um, yes. Sort of. Though it's got to be said, people are far more likely to talk about the success of their prayers to St Jude than the failures. And as a distinguished doctor said while looking at the collection of wooden crutches at Lourdes, "I'd be a lot more convinced if one of them was a wooden leg." The fact is, the placebo effect is immensely powerful. We know lots about placebos. We know, for instance, that green sugar pills are more effective than red ones for treating stress disorders. We know that two sugar pills are more effective than one. We know that an injection of saline solution is more effective than either sort of sugar pill. And we know that any given placebo is only as effective as the confidence and general spiel of the giver will allow it to be.
And this is where alternative practice thrives. I'm not saying that all homeopaths are charlatans. I'm sure that the vast majority of them are totally sincere about what they practice. As an atheist, I don't doubt the sincerity of people who recite great tracts of ancient metaphorical text at me as though it's history. I do my best to respect their beliefs, I really do. I just think they're idiots for holding them. But just as a belief in burning pits of boiling oil seems to bring comfort to some proportion of the population, so does the promise - that if you take this tincture, you'll get better - actually help some people to do so.
This is partly because of the power of blind faith, and partly because, as human beings, we rely on ritual to make sense of things we don't really understand. And, let's face it; we've lost a lot of the showmanship in medicine. We don't make with the slaughtered goat, chicken bones and the shaky-thing with feathers any more. Your average doctor, working under considerable pressure, doesn't have the time or, let's face it, often the social skills, to make a patient feel properly served, listened to, or cared about.
Don't underestimate the value of this, A very interesting passage in Malcolm Gladwell's recent book, Blink, showed that a surgeon's likelihood of being sued for negligence at any point in their career wasn't related even in the slightest to their actual record of successful or unsuccessful outcomes: it was entirely related to the way that they interacted with their patients. So someone who has a chronic condition - like asthma, psoriasis or eczema - that is likely to go into periods of remission, will benefit from the in-depth, concerned consultation about the whole of their life as offered by the average homeopathic consultant. And if spontaneous remission occurs, give the homeopath credit for that remission. This is why people's perceptions of the value of their treatment from alternative medicine practitioners are always so much more positive than their memories of treatment by doctors, despite the fact that the statistics simply don't bear out the perception.
So, sure, go ahead and see a homeopath for your gout, or your acne. But please, please, please; don't see it as a substitute for real, empirically tested and proven, actual medicines. Prophylactic malaria preventatives may have unpleasant side-effects, but no side-effect in the world will be as bad as the ones you'll get from going off to the rainforest with a little bottle of boiled water and a bundle of belief.