Bad Science. Ben Goldacre

people don’t buy expensive cosmetics simply because they have a belief in their efficacy, because it’s ‘a bit more complicated than that’: these are luxury goods, status items, and they are bought for all kinds of interesting reasons.

      But it’s not entirely morally neutral. Firstly, the manufacturers of these products sell shortcuts to smokers and the obese; they sell the idea that a healthy body can be attained by using expensive potions, rather than simple old-fashioned exercise and eating your greens. This is a recurring theme throughout the world of bad science.

      More than that, these adverts sell a dubious world view. They sell the idea that science is not about the delicate relationship between evidence and theory. They suggest, instead, with all the might of their international advertising budgets, their Microcellular Complexes, their Neutrillium XY, their Tenseur Peptidique Végétal and the rest, that science is about impenetrable nonsense involving equations, molecules, sciencey diagrams, sweeping didactic statements from authority figures in white coats, and that this sciencey-sounding stuff might just as well be made up, concocted, confabulated out of thin air, in order to make money. They sell the idea that science is incomprehensible, with all their might, and they sell this idea mainly to attractive young women, who are disappointingly underrepresented in the sciences.

      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.*

      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