Homeopathy: The Test - questions and answers
How did homeopathy start?
Homeopathy was founded by Samuel Hahnemann (1755-1843). He trained as a physician, but thought that many of the techniques he learned were brutal and ineffective.
Disillusioned with medicine, he started work as a translator. It was then that he came across a book which mentioned that a bark extract, quinine, could be used to treat malaria. He found himself wondering why this worked.
Hahnemann started experimenting on himself. He noticed that when he took a dose of quinine he experienced feverish symptoms similar to those of malaria. This led him to formulate his universal rule for homeopathy: that like cures like.
Jacques Benveniste claimed he could explain homeopathy in the eighties. What happened to him?
Jacques Benveniste published a controversial paper on homeopathy in Nature in 1988. He implied that water had properties that meant that it 'remembered' what chemicals it had been in contact with. This results of this paper have since been called into question.
Following this incident, Benveniste lost his funding from the French government. However, he has continued his research with a small team and still stands by his original results.
His new research takes the concept of the memory of water a step further. He now claims to be able to record a signal stored in the water and turn it into a computer file, which can be emailed around the world. This emailed file can be played back into a sample of pure water, which then takes on the properties of the original substance.
These claims have met with even greater scepticism than his original results and have earned him an unprecedented second IgNobel prize.
How can the 'placebo effect' explain homeopathy in animals and babies?
Many people claim that homeopathy works simply because people believe it will. This is known as the placebo effect.
A major part of the placebo effect is the hope and peace-of-mind that you get from doing something you think will be beneficial. This requires the knowledge that the treatment is supposed to help you. Therefore the placebo effect should only work in humans old enough to know what a medicine is.
However, homeopathy is also believed to work on animals and babies. Could the placebo effect also explain this?
The apparent effect of a placebo could also be due to other interventions that occur at the same time - changes in diet for instance, or just increased care and attention. There could also be a degree of wishful thinking on behalf of the human observer - believing an animal or baby that received the treatment has improved more than it has because of unconscious bias. There might also be an indirect placebo effect - the treatment makes a carer feel more relaxed and this is picked up by an animal or baby.
Because of these possibilities, research (even on animals and babies) can only be convincing if it is 'double blind' and placebo controlled. This means that the researcher mustn't know which subjects have received the test treatment and which have received the placebo.
How has homeopathy performed in clinical trials?
There have been over 200 trials published that have examined the effectiveness of homeopathic medicines. The majority of these have found some positive effect of homeopathy. However, in such a comparison you have to take into account publication bias: a positive study is more likely to get published than a negative study. Opinions differ as to whether analysing all these studies together is useful and whether the overall evidence comes out significantly in favour of homeopathy.
The critics point to the lack of strong repetitions of studies. For instance David Reilly's work on allergy is often regarded as the best clinical evidence for homeopathy. However, in a recent attempt to investigate the same condition the results came out negative. Dr Reilly believes this is down to differences in the experimental method. Until a result can be reliably replicated in favour of homeopathy in independent laboratories the scientific community will remain sceptical.
What else would qualify for the Randi Million Dollar challenge?
The Randi challenge doesn't only apply to homeopathy, any paranormal effect would qualify. It started in 1964 when, during a heated radio debate, a parapsychologist challenged Randi to put his money where his mouth is. Randi replied by offering $10,000 of his own money and the Paranormal Challenge was born.
Since then, the prize fund has grown through donations and pledges by fellow sceptics to reach a total of more than $1m. To apply for the prize you just need to fill in a form on Randi's website.
So far, there have been applications from practitioners of therapeutic touch, dowsers and psychic readers. One recent application was from a 10-year-old Russian girl who claimed to be able to see using mental perception. When her mother blindfolded her she went on to successfully read out cards held up in front of her face. But when Randi applied the blindfolding, carefully making sure that there was no gap between the blindfold and her unusually concave nose, her mental perception deserted her. Needless to say, she failed the test.