An article that appeared in the New Scientist ( issue no2292 ) on 26 May 2001
As soon as his best friend moved away, the eight-year-old boy started complaining of pains in his legs. The family doctor couldn't work it out, so he referred the case to the hospital. The neurologists checked him out and couldn't find anything. And so the boy was referred to yet another specialist.
This time the doctor was less interested in the boy's legs than in what he liked to eat and drink, how he slept and so on. Did he have any unusual habits? "He hates buttons," his mother said. "Ever since he was a baby he's refused to wear clothes with buttons." The doctor consulted his texts then prescribed some medicine. It worked. At the next appointment the boy walked into the clinic without any pain in his legs, and he was wearing a cardigan with buttons.
The magic potion was a homeopathic remedy, jalapa, based on the root of the Mexican shrub Exogonium purga. And it was prescribed by Bob Leckridge, associate specialist at Glasgow Homeopathic Hospital. In common with all homeopaths, he has a rather different approach from the majority of the medical profession.
Leckridge starts a consultation by making a study of a patient's habits, character, likes and dislikes. He uses this information to put together a "picture" of the patient. He then looks up possible remedies in a 'repertory" - a list of symptoms and their associated remedies. All these remedies have been tested in a process called proving, in which homeopaths record the symptoms they produce in healthy people. Leckridge then cross-checks the possible remedies in a homeopathic formulary to find out which one produces a picture closest to the patient's. This is what is prescribed.
Homeopaths believe their remedies have a similar effect to vaccination. By using a substance that produces symptoms similar to the ones they're trying to cure, they trigger a healing response in the body. As laid down at the end of the 18th century by homeopathy's founder, German physician Samuel Hahnemann, "like cures like".
Hahnemann came up with his theory after noticing that the malaria drug quinine actually produced symptoms very similar to malaria when given to a healthy person. He then started testing other drugs to see what symptoms they produced. In the hope of making the drugs safer, he started diluting them. To his surprise, he found that the effects produced grew stronger the more he diluted the solution.
Today, homeopathic remedies are dissolved in ethanol to produce the "mother tincture". This is then repeatedly diluted, starting with 1 part tincture to 99 parts of a mixture of water and ethanol, then 1 part of the resulting solution to another 99 parts, and so on. Solutions are usually diluted six or 30 times, but up to 200 dilutions can be performed. Each time the remedy is diluted it is vigorously shaken, or 'succussed".
The original ingredients are usually natural substances. Some, called nosodes, come from matter produced by the disease itself, such as tissue from an infected gland. Some are straight from the "eye of newt" recipe book - black Cuban spider, anal gland of skunk - but others are more familiar. Red onion has a "remedy picture' that includes watery eyes and sneezing. Homeopaths prescribe it for some allergies. Nux vomica, the poison nut, causes irritability, aversion to noise, bad breath and nausea. Not surprisingly, it's a popular hangover remedy.
So are homeopaths quacks? If so, millions of people have been taken in and Britain's National Health Service supports them in their credulity. There are five NHS homeopathic centres. Glasgow's alone sees 2500 new patients a year. Between them, British consumers spend more than £20 million a year on over-the-counter homeopathic remedies. It's difficult to say how many practitioners there are in Britain, as anyone can call themselves a homeopath, but a recent University of Exeter report found that 2696 people were members of homeopathic practitioner organisations.
Yet despite the popularity of homeopathy, practitioners have yet to convince the majority of scientists that there is anything in it other than the placebo effect.
Because homeopathy really shouldn't work. There are two big problems. First, the key ingredient in any homeopathic remedy is diluted to such an extent that the chance of finding even a single molecule of the original substance in a dose is vanishingly small. Secondly, the dose-response relationship - that is, the more you take, the more powerful the response-is apparently reversed in homeopathy. The more dilute the remedy, the stronger the effect.
Being asked to believe two impossible things before breakfast can make people angry. Even with the general public stampeding to their doors, homeopaths are fighting a rearguard action against those who say they're charlatans. Although happy to continue practising as long as their patients keep coming, homeopaths would dearly love a scientific explanation of their art.
So it was with some enthusiasm that the homeopathic community greeted a 1988 paper in Nature (vol 333, p 816) by immunologist Jacques Benveniste, then based at INSERM, the French national institute for medical research. He suggested that anti-immunoglobulin E serum diluted way past the point at which it's reasonable to expect a single molecule of the original substance to be present still produces a biological effect. From this came the idea that water has memory - that it could somehow "remember" molecules that had once been dissolved in it and act as if they were still there.
Unfortunately, his results could not be replicated despite the efforts of several teams-most famously a team assembled by Nature which included magician and arch-sceptic James Randi. Randi's foundation has since offered a $1 million prize for anyone who can invent a reproducible test that can tell the difference between a homeopathic preparation and a control. It remains unclaimed.
Since what has come to be known as the Benveniste affair, scientific attention has concentrated on statistical reviews of reputable clinical trials. Most notably, Klaus Linde of the Centre for Complementary Medicine Research at the Technical University of Munich led an analysis of 89 homeopathic trials. Published in The Lancet in 1997 (vol 350, p 834), the study concluded that
the trial results were "not compatible with the hypothesis that the clinical effects of homeopathy are completely due to placebo". A follow-up paper in 1998 in The journal of Alternative and Complementary Medicine (vol 4, p 371) went further, concluding that "individualised homeopathy has an effect over placebo". Not quite a ringing endorsement - but not a dismissal either.
Of course, some people think grown-ups shouldn't be wasting their time looking for something that shouldn't be there. Jan Vandenbroucke, professor of clinical epidemiology at the University of Leiden in the Netherlands, says reviews of trials are pointless as any positive results can't be interpreted within our current understanding. "Nothing can be ruled out in principle, but it seems quite a remote possibility that an infinite dilution may have chemical activity," he says. "Empirical data do not necessarily overrule theory - when data are totally incompatible with accepted scientific theory that has been shown to work, theory overrules empirical data."
Telling homeopaths not to be so silly was also, until recently, a pastime of Madeleine Ennis, professor of immunopharmacology at Queen's University, Belfast. She did it so often that she was asked to join a multi-centre European study to look at the effects of "highly dilute" solutions - well into the homeopathic range - of histamine on human basophils.
Basophils are white blood cells involved in inflammation. They make many biologically active substances, including histamine, which they release in response to an attack. Once histamine has been released, it has a negative-feedback effect on basophils, stopping them from releasing any more.
Four separate research centres were sent some test tubes of pure water and some of histamine at homeopathic dilutions. They weren't told which contained pure water and which the homeopathically prepared solution. The results? All four centres found that the ultra-dilute solutions inhibited histamine release from basophils, just like histamine itself, and the results were statistically significant at three of the centres.
Ennis was not best pleased. She had set out to destroy the central tenet of homeopathy but had ended up shoring it up. Her reluctant conclusion? "Despite my fundamental reservations against the science of homeopathy, the results compel me to suspend my disbelief and start searching for a rational explanation for our findings. The Belfast team’s results are due to be published in Inflamation Research this summer.
Ennis says that if her results are real we may have to rewrite physics and chemistry. But Peter Fisher, director of research at the Royal London Homoeopathic Hospital, proffers a less radical explanation. "I think it's to do with changes in the structure of the water," he says. "Somehow information is stored in water." He says the act of preparing a homeopathic remedy imprints this information on the water. Ordinary, untreated water has no structure.
"The reason why people find [homeopathy] so challenging is that we are used to thinking about pharmacology in molecular terms," Fisher continues. "If you take homeopathic medicine to be analysed, a pharmacologist would say it's water and ethanol and sugar, and that's true. But if you take a floppy disc to a chemist he will say it is ferric oxide and vinyl. The information is
stored in physical form: the alignment of the dipoles of ferric oxide." We shouldn't write off homeopathy simply because the dose-response relationship is reversed, he adds - we just don't know enough about ultra-dilute solutions.
Although resigned to practising without an accepted explanation, a scientific model would at last enable homeopaths to discover what works best. At the moment, there's a distinct lack of agreement about best practice. Different homeopathy schools, countries and practitioners perform their art in different ways. Many homeopaths tell you not to eat or drink strong flavours when taking their remedies. Others think that's ludicrous. Some favour combination remedies. Others prefer a single one. Who's right? No one knows. Clearly, some more robust trials are needed if scientists are to stop shouting "rubbish!" whenever the "h word" is mentioned.
But then, as a scientifically trained friend commented after taking an irritatingly successful homeopathic treatment for hayfever: "It's witchcraft. But it's bloody effective witchcraft."
Jane Seymour is a health journalist Living in London