2008 - Bad Science Page 4
In fact, they sell the world view of ‘Teen Talk Barbie’ from Mattel, who shipped with a sweet little voice circuit inside her so she could say things like, ‘Math class is tough!’, ‘I love shopping!’ and ‘Will we ever have enough clothes?’ when you pressed her buttons. In December 1992 the feminist direct-action Barbie Liberation Organization switched the voice circuits of hundreds of Teen Talk Barbies and GI Joe dolls in American shops. On Christmas Day Barbie said ‘Dead men tell no lies’ in a nice assertive voice, and the boys got soldiers under the tree telling them ‘Math class is tough!’ and asking ‘Wanna go shopping?’
The work of the BLO is not yet done.
4 Homeopathy
And now for the meat. But before we take a single step into this arena, we should be clear on one thing: despite what you might think, I’m not desperately interested in Complementary and Alternative Medicine (a dubious piece of phraseological rebranding in itself). I am interested in the role of medicine, our beliefs about the body and healing, and I am fascinated—in my day job—by the intricacies of how we can gather evidence for the benefits and risks of a given intervention.
Homeopathy, in all of this, is simply our tool.
So here we address one of the most important issues in science: how do we know if an intervention works? Whether it’s a face cream, a detox regime, a school exercise, a vitamin pill, a parenting programme or a heart-attack drug, the skills involved in testing an intervention are all the same. Homeopathy makes the clearest teaching device for evidence-based medicine for one simple reason: homeopaths give out little sugar pills, and pills are the easiest thing in the world to study.
By the end of this section you will know more about evidence-based medicine and trial design than the average doctor. You will understand how trials can go wrong, and give false positive results, how the placebo effect works, and why we tend to overestimate the efficacy of pills. More importantly, you will also see how a health myth can be created, fostered and maintained by the alternative medicine industry, using all the same tricks on you, the public, which big pharma uses on doctors. This is about something much bigger than homeopathy.
What is homeopathy?
Homeopathy is perhaps the paradigmatic example of an alternative therapy: it claims the authority of a rich historical heritage, but its history is routinely rewritten for the PR needs of a contemporary market; it has an elaborate and sciencey-sounding framework for how it works, without scientific evidence to demonstrate its veracity; and its proponents are quite clear that the pills will make you better, when in fact they have been thoroughly researched, with innumerable trials, and have been found to perform no better than placebo.
Homeopathy was devised by a German doctor named Samuel Hahnemann in the late eighteenth century. At a time when mainstream medicine consisted of blood-letting, purging and various other ineffective and dangerous evils, when new treatments were conjured up out of thin air by arbitrary authority figures who called themselves ‘doctors’, often with little evidence to support them, homeopathy would have seemed fairly reasonable.
Hahnemann’s theories differed from the competition because he decided—and there’s no better word for it—that if he could find a substance which would induce the symptoms of a disease in a healthy individual, then it could be used to treat the same symptoms in a sick person. His first homeopathic remedy was Cinchona bark, which was suggested as a treatment for malaria. He took some himself, at a high dose, and experienced symptoms which he decided were similar to those of malaria itself:
My feet and finger-tips at once became cold; I grew languid and drowsy; my heart began to palpitate; my pulse became hard and quick; an intolerable anxiety and trembling arose…prostration…pulsation in the head, redness in the cheek and raging thirst…intermittent fever…stupefaction…rigidity…
–and so on.
Hahnemann assumed that everyone would experience these symptoms if they took Cinchona (although there’s some evidence that he just experienced an idiosyncratic adverse reaction). More importantly, he also decided that if he gave a tiny amount of Cinchona to someone with malaria, it would treat, rather than cause, the malaria symptoms. The theory of ‘like cures like’ which he conjured up on that day is, in essence, the first principle of homeopathy.*
≡ At proper high doses, Cinchona contains quinine, which can genuinely be used to treat malaria, although most malarial parasites are immune to it now.
Giving out chemicals and herbs could be a dangerous business, since they can have genuine effects on the body (they induce symptoms, as Hahnemann identified). But he solved that problem with his second great inspiration, and the key feature of homeopathy that most people would recognise today: he decided—again, that’s the only word for it—that if you diluted a substance, this would ‘potentise’ its ability to cure symptoms, ‘enhancing’ its ‘spirit-like medicinal powers’, and at the same time, as luck would have it, also reducing its side-effects. In fact he went further than this: the more you dilute a substance, the more powerful it becomes at treating the symptoms it would otherwise induce.
Simple dilutions were not enough. Hahnemann decided that the process had to be performed in a very specific way, with an eye on brand identity, or a sense of ritual and occasion, so he devised a process called ‘succussion’. With each dilution the glass vessel containing the remedy is shaken by ten firm strikes against ‘a hard but elastic object’. For this purpose Hahnemann had a saddlemaker construct a bespoke wooden striking board, covered in leather on one side, and stuffed with horsehair. These ten firm strikes are still carried out in homeopathy pill factories today, sometimes by elaborate, specially constructed robots.
Homeopaths have developed a wide range of remedies over the years, and the process of developing them has come to be called, rather grandly, ‘proving’ (from the German Prufung). A group of volunteers, anywhere from one person to a couple of dozen, come together and take six doses of the remedy being ‘proved’, at a range of dilutions, over the course of two days, keeping a diary of the mental, physical and emotional sensations, including dreams, experienced over this time. At the end of the proving, the ‘master prover’ will collate the information from the diaries, and this long, unsystematic list of symptoms and dreams from a small number of people will become the ‘symptom picture’ for that remedy, written in a big book and revered, in some cases, for all time. When you go to a homeopath, he or she will try to match your symptoms to the ones caused by a remedy in a proving.
There are obvious problems with this system. For a start, you can’t be sure if the experiences the ‘provers’ are having are caused by the substance they’re taking, or by something entirely unrelated. It might be a ‘nocebo’ effect, the opposite of placebo, where people feel bad because they’re expecting to (I bet I could make you feel nauseous right now by telling you some home truths about how your last processed meal was made); it might be a form of group hysteria (‘Are there fleas in this sofa?’); one of them might experience a tummy ache that was coming on anyway; or they might all get the same mild cold together; and soon.
But homeopaths have been very successful at marketing these ‘provings’ as valid scientific investigations. If you go to Boots the Chemist’s website, www.bootslearningstore.co.uk, for example, and take their 16-plus teaching module for children on alternative therapies, you will see, amongst the other gobbledegook about homeopathic remedies, that they are teaching how Hahnemann’s provings were ‘clinical trials’. This is not true, as you can now see, and that is not uncommon.
Hahnemann professed, and indeed recommended, complete ignorance of the physiological processes going on inside the body: he treated it as a black box, with medicines going in and effects coming out, and championed only empirical data, the effects of the medicine on symptoms (‘The totality of symptoms and circumstances observed in each individual case,’ he said, ‘is the one and only indication that can lead us to the choice of the remedy’).
This is the polar op
posite of the ‘Medicine only treats the symptoms, we treat and understand the underlying cause’ rhetoric of modern alternative therapists. It’s also interesting to note, in these times of ‘natural is good’, that Hahnemann said nothing about homeopathy being ‘natural’, and promoted himself as a man of science.
Conventional medicine in Hahnemann’s time was obsessed with theory, and was hugely proud of basing its practice on a ‘rational’ understanding of anatomy and the workings of the body. Medical doctors in the eighteenth century sneeringly accused homeopaths of ‘mere empiricism’, an over-reliance on observations of people getting better. Now the tables are turned: today the medical profession is frequently happy to accept ignorance of the details of mechanism, as long as trial data shows that treatments are effective (we aim to abandon the ones that aren’t), whereas homeopaths rely exclusively on their exotic theories, and ignore the gigantic swathe of negative empirical evidence on their efficacy. It’s a small point, perhaps, but these subtle shifts in rhetoric and meaning can be revealing.
The dilution problem
Before we go any further into homeopathy, and look at whether it actually works or not, there is one central problem we need to get out of the way.
Most people know that homeopathic remedies are diluted to such an extent that there will be no molecules of it left in the dose you get. What you might not know is just how far these remedies are diluted. The typical homeopathic dilution is 30C: this means that the original substance has been diluted by one drop in a hundred, thirty times over. In the ‘What is homeopathy?’ section on the Society of Homeopaths’ website, the single largest organisation for homeopaths in the UK will tell you that ‘30C contains less than one part per million of the original substance.’
‘Less than one part per million’ is, I would say, something of an understatement: a 30C homeopathic preparation is a dilution of one in 10030, or rather 1060, or one followed by sixty zeroes. To avoid any misunderstandings, this is a dilution of one in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000, or, to phrase it in the Society of Homeopaths’ terms, ‘one part per million million million million million million million million million million’. This is definitely ‘less than one part per million of the original substance’.
For perspective, there are only around 100,000,000,000,000, 000,000,000,000,000,000 molecules of water in an Olympic-sized swimming pool. Imagine a sphere of water with a diameter of 150 million kilometres (the distance from the earth to the sun). It takes light eight minutes to travel that distance. Picture a sphere of water that size, with one molecule of a substance in it: that’s a 30C dilution.*
≡ For pedants, it’s a 30.89C dilution.
At a homeopathic dilution of 200C (you can buy much higher dilutions from any homeopathic supplier) the treating substance is diluted more than the total number of atoms in the universe, and by an enormously huge margin. To look at it another way, the universe contains about 3 x 1080 cubic metres of storage space (ideal for starting a family): if it was filled with water, and one molecule of active ingredient, this would make for a rather paltry 55C dilution.
We should remember, though, that the improbability of homeopaths’ claims for how their pills might work remains fairly inconsequential, and is not central to our main observation, which is that they work no better than placebo. We do not know how general anaesthetics work, but we know that they do work, and we use them despite our ignorance of the mechanism. I myself have cut deep into a man’s abdomen and rummaged around his intestines in an operating theatre—heavily supervised, I hasten to add—while he was knocked out by anaesthetics, and the gaps in our knowledge regarding their mode of action didn’t bother either me or the patient at the time.
Moreover, at the time that homeopathy was first devised by Hahnemann, nobody even knew that these problems existed, because the Italian physicist Amadeo Avogadro and his successors hadn’t yet worked out how many molecules there are in a given amount of a given substance, let alone how many atoms there are in the universe. We didn’t even really know what atoms were.
How have homeopaths dealt with the arrival of this new knowledge? By saying that the absent molecules are irrelevant, because ‘water has a memory’. This sounds feasible if you think of a bath, or a test tube full of water. But if you think, at the most basic level, about the scale of these objects, a tiny water molecule isn’t going to be deformed by an enormous arnica molecule, and be left with a ‘suggestive dent’, which is how many homeopaths seem to picture the process. A pea-sized lump of putty cannot take an impression of the surface of your sofa.
Physicists have studied the structure of water very intensively for many decades, and while it is true that water molecules will form structures round a molecule dissolved in them at room temperature, the everyday random motion of water molecules means that these structures are very short-lived, with lifetimes measured in picoseconds, or even less. This is a very restrictive shelf life.
Homeopaths will sometimes pull out anomalous results from physics experiments and suggest that these prove the efficacy of homeopathy. They have fascinating flaws which can be read about elsewhere (frequently the homeopathic substance—which is found on hugely sensitive lab tests to be subtly different from a non-homeopathic dilution—has been prepared in a completely different way, from different stock ingredients, which is then detected by exquisitely sensitive lab equipment). As a ready shorthand, it’s also worth noting that the American magician and ‘debunker’ James Randi has offered a $1 million prize to anyone demonstrating ‘anomalous claims’ under laboratory conditions, and has specifically stated that anyone could win it by reliably distinguishing a homeopathic preparation from a non-homeopathic one using any method they wish. This $1 million bounty remains unclaimed.
Even if taken at face value, the ‘memory of water’ claim has large conceptual holes, and most of them you can work out for yourself. If water has a memory, as homeopaths claim, and a one in 1060 dilution is fine, then by now all water must surely be a health-giving homeopathic dilution of all the molecules in the world. Water has been sloshing around the globe for a very long time, after all, and the water in my very body as I sit here typing away in London has already been through plenty of other people’s bodies before mine. Maybe some of the water molecules sitting in my fingers as I type this sentence are currently in your eyeball. Maybe some of the water molecules fleshing out my neurons as I decide whether to write ‘wee’ or ‘urine’ in this sentence are now in the Queen’s bladder (God bless her): water is a great leveller, it gets about. Just look at clouds.
How does a water molecule know to forget every other molecule it’s seen before? How does it know to treat my bruise with its memory of arnica, rather than a memory of Isaac Asimov’s faeces? I wrote this in the newspaper once, and a homeopath complained to the Press Complaints Commission. It’s not about the dilution, he said: it’s the succussion. You have to bang the flask of water briskly ten times on a leather and horsehair surface, and that’s what makes the water remember a molecule. Because I did not mention this, he explained, I had deliberately made homeopaths sound stupid. This is another universe of foolishness.
And for all homeopaths’ talk about the ‘memory of water’, we should remember that what you actually take, in general, is a little sugar pill, not a teaspoon of homeopathically diluted water—so they should start thinking about the memory of sugar, too. The memory of sugar, which is remembering something that was being remembered by water (after a dilution greater than the number of atoms in the universe) but then got passed on to the sugar as it dried. I’m trying to be clear, because I don’t want any more complaints.
Once this sugar which has remembered something the water was remembering gets into your body, it must have some kind of effect. What would that be? Nobody knows, but you need to take the pills regularly, apparently, in a dosing regime which is suspiciously similar to that for medical drugs (which are given at intervals spaced according
to how fast they are broken down and excreted by your body).
I demand a fair trial
These theoretical improbabilities are interesting, but they’re not going to win you any arguments: Sir fohn Forbes, physician to Queen Victoria, pointed out the dilution problem in the nineteenth century, and 150 years later the discussion has not moved on. The real question with homeopathy is very simple: does it work? In fact, how do we know if any given treatment is working?
Symptoms are a very subjective thing, so almost every conceivable way of establishing the benefits of any treatment must start with the individual and his or her experience, building from there. Let’s imagine we’re talking—maybe even arguing—with someone who thinks that homeopathy works, someone who feels it is a positive experience, and who feels they get better, quicker, with homeopathy. They would say: ‘All I know is, I feel as if it works. I get better when I take homeopathy.’ It seems obvious to them, and to an extent it is. This statement’s power, and its flaws, lie in its simplicity. Whatever happens, the statement stands as true.
But you could pop up and say: ‘Well, perhaps that was the placebo effect.’ Because the placebo effect is far more complex and interesting than most people suspect, going way beyond a mere sugar pill: it’s about the whole cultural experience of a treatment, your expectations beforehand, the consultation process you go through while receiving the treatment, and much more.
We know that two sugar pills are a more effective treatment than one sugar pill, for example, and we know that salt-water injections are a more effective treatment for pain than sugar pills, not because salt-water injections have any biological action on the body, but because an injection feels like a more dramatic intervention. We know that the colour of pills, their packaging, how much you pay for them and even the beliefs of the people handing the pills over are all important factors. We know that placebo operations can be effective for knee pain, and even for angina. The placebo effect works on animals and children. It is highly potent, and very sneaky, and you won’t know the half of it until you read the ‘placebo’ chapter in this book.