Homeopathy is based on two main assumptions: ‘like cures like’ means that onions, which make our eyes water, are considered to be a cure for hay fever and other conditions characterised by watery eyes. Similarly, coffee, which keeps us awake, is prescribed by homeopaths against insomnia. ‘Less is more’ indicates that the typical homeopathic preparation is diluted to the extreme. Most homeopathic remedies are ‘C 30’ which means they have been diluted 30 times in steps 1:100. At each step it must be vigorously shaken. Homeopaths don’t mind the fact that beyond ‘C12’ the likelihood of the presence of a single active molecule in their remedies is zero. On the contrary, they call the process of serial dilution, combined with shaking, ‘potentisation’ because they believe that it renders their remedies not less but more potent.
Considering the undeniable implausibility of these assumptions, it is hardly surprising that homeopathy infuriates scientists and sceptics alike. If homeopathy works, the laws of nature must be wrong, they insist. But homeopaths argue that the proof of the pudding is in the eating, pointing to the many millions of patients worldwide who swear by their treatments and the numerous studies which, in their view, demonstrate that homeopathy is effective after all.
The trouble is, however, that their view relies on evidence that is flawed, exaggerated or cherry-picked. Whenever a panel of independent scientists critically assess the totality of the reliable evidence, the result is devastatingly negative. Recently, the Australian National Health and Research Council published the most rigorous evaluation of homeopathy in its 200-year-long history. The experts concluded that ‘the evidence… does not show that homeopathy is effective… People who choose homeopathy may put their health at risk…’
Despite such clear words, the public is often confused about the nature and the value of homeopathy. Perhaps they are impressed by the many celebrities promoting it, the fact that Boots and other pharmacies sell it, or the frequently misleading press coverage on this subject. The truth is, however, surprisingly plain and simple.
- The basic assumptions of homeopathy fly in the face of science.
- The totality of the results from clinical trials on human patients or animals fails to show that homeopathic remedies work.
- The benefits that many patients experience after consulting a homeopath are due to a placebo response or other non-specific effects which have nothing to do with the remedy itself.
- Being devoid of any active substance, the homeopathic remedy may be safe, but this does not necessarily apply to homeopaths as well. When patients follow their advice to forfeit effective conventional therapies for serious conditions, homeopathy becomes life-threatening.
- The money spent on homeopathy is considerable and could be used more wisely to pay for interventions that work.
So, why is homeopathy still available on the NHS? Five years ago, an ‘Evidence Check’ by our Science and Technology Select Committee concluded that the government should stop allowing the funding of homeopathy on the NHS. Despite this strong, unequivocal recommendation and the overwhelming scientific evidence, politicians in their infinite wisdom decided that homeopathy stays because patient choice trumps science. Sounds so much better than admitting to surrendering to royal meddling, doesn’t it?
Professor Edzard Ernst is emeritus professor of complementary medicine at Peninsula medical school, University of Exeter.