Abstract: Homeopathy works. Except it doesn't.

"What?!," I hear you exclaim, a panicky bead or two of perspiration taking root on your furrowed brow, "Has our Sceptic Guru gone soft? Is he now claiming that homeopathy works? Oh no, Sceptic Guru, say it ain't so!"

Fear not, lover of science and logic, to paraphrase the Iron Lady - this Guru's not for turning.
So why suggest that homeopathy works? Because it does, but it has nothing to do with homeopathy. Confused? Well then, read on.

Homeopathy is essentially an alternative form of treatment in which practitioners use highly diluted forms of medication - called therapies - to address a certain range of ailments, with the central tenet of using 'like to cure like'. In other words, homeopaths believe that to treat someone you need to uncover what substance is causing their ailment and use a diluted solution of that substance to help the body fight it.

There's a certain element of familiar logic in that, after all immunisation against any disease involves in the injection of minute preparations of an agent that represents the micro-organism that causes the disease, in order to activate the body's immune system.

However, it's the phrase "highly diluted forms of medication" that warrants closer inspection; and this when we start having fun with maths. Homeopathic remedies are made from 'tinctures' - substantial water or water-alcohol mixtures in which an active ingredient has been soaked. These tinctures are then constantly diluted and shaken vigorously forwards and backwards and sideways in a carefully followed procedure known as succussion. This process is repeated over and over, each time taking one part in a hundred of the increasingly diluted mixture and diluting even further. In an interesting execution of paradoxical marketing, homeopaths claim the more dilute the remedy, the greater its 'potency'.

So how diluted (are therefore 'potent') are these remedies? A typical remedy dilution is 30C, which means the one part per hundred dilution has been repeated 30 times, which is 10030 or 1060 or 1 followed by 60 zeroes - suffice to say a dilution without any molecular trace whatsoever of the so-called active ingredient.

Ben Goldacre puts this into perspective thus: "...it equates to one molecule of the substance in a sphere of water whose diameter is roughly the distance from the earth to the sun."

Homeopaths counter this by saying that water has 'memory' and that is retains some structure of the active ingredient dissolved in it. However, unlike those of a solid, molecules of a liquid such as water are in constant motion and therefore any supposition that the molecules can permanently mimic the molecule of an active ingredient is ridiculous.

As the leading science writer Toby Murcott summarises in his book 'The Whole Story': "In short, homeopathy is a dead duck scientifically. It uses remedies that contain no active ingredients and a laughable principle that water has a 'memory'".

So if there cannot be any chemical foundation for the efficacy of homeopathy, let's get back to the original question: why does homeopathy work?

For the answer we need to understand a little about the human sensation of pain or discomfort and the ceremony of intervention.

Pain, and the physical feeling of discomfort, is a highly complex concept, and it has a wide range of determinants that are not only biological, chemical, and physiological in nature, but also emotional, psychological and even social. The reality is that we don't fully understand the mechanisms behind pain or the sensations of feeling ill, but we do know that the brain - itself an incredibly complex organism - plays a central part.

We also know that because the brain is responsible for the sensations of feeling ill, we can fool the brain into making us feel better - the so called 'placebo effect'.

In a similar way that the anticipation of a reward can release dopamine - a neurotransmitter that makes us feel good and therefore is in itself a reward - the anticipation of us getting better can make us feel better. This is the power of intervention, or the psychological effects of the input of a consulting specialist.

Humans are conditioned to react to intervention. When we feel ill and we visit a clinician, we believe that the clinician will help us and trust that what they give us will make us feel better.

Studies of the placebo effect have furthermore shown that the more dramatic the intervention, the more powerful the placebo effect. In other words, a sugar-coated pill with no active ingredient could help cure a mild headache, but for something more serious, an injection of a simple saline solution could work wonders! For top-end ailments, nothing beats an impressive looking piece of machinery with flashing lights that every now and then goes "ping!"

Studies have also shown that the ceremony of intervention is an important factor in the effectiveness of a placebo. A sugar-coated pill handed to a patient by an abrupt doctor-figure with the simple recommendation to take it will not be as affective as the same pill handed to the same patient by a caring doctor-figure who speaks wondrously about the effectiveness of the drug.

And this is where homeopathy scores. A visit to a typical British GP on the NHS will take all of six to ten minutes. This is frustrating for both the doctor and the patient. Homeopaths on the other hand often spend longer with their patients, finding time to talk to them about other elements of wellness such as diet, exercise and lifestyle; all elements that contribute to feeling better. In other words, homeopaths may just be a little better at spreading some TLC.

According to Murcott, most doctors are healers first and scientists second. Homeopaths may not have science on their side, but they seem to have more time for healing; so whereas there may be no clinical trials to support the efficacy of their treatment, there are numerous anecdotal reports from people who feel better after visiting a homeopath.

And that, dear Guru reader, is why homeopathy works.

Originally published in the 4th issue of Guru magazine: