The Great Game

MADELEINE Ennis, a pharmacologist at Queen's University, Belfast, was the scourge of homeopathy. She railed against its claims that a chemical remedy could be diluted to the point where a sample was unlikely to contain a single molecule of anything but water, and yet still have a healing effect. Until, that is, she set out to prove once and for all that homeopathy was bunkum.

In her most recent paper, Ennis describes how her team looked at the effects of ultra-dilute solutions of histamine on human white blood cells involved in inflammation. These "basophils" release histamine when the cells are under attack. Once released, the histamine stops them releasing any more. The study, replicated in four different labs, found that homeopathic solutions - so dilute that they probably didn't contain a single histamine molecule - worked just like histamine. Ennis might not be happy with the homeopaths' claims, but she admits that an effect cannot be ruled out.

So how could it happen? Homeopaths prepare their remedies by dissolving things like charcoal, deadly nightshade or spider venom in ethanol, and then diluting this "mother tincture" in water again and again. No matter what the level of dilution, homeopaths claim, the original remedy leaves some kind of imprint on the water molecules. Thus, however dilute the solution becomes, it is still imbued with the properties of the remedy.

You can understand why Ennis remains sceptical. And it remains true that no homeopathic remedy has ever been shown to work in a large randomised placebo-controlled clinical trial. But the Belfast study (Inflammation Research, vol 53, p 181) suggests that something is going on. "We are," Ennis says in her paper, "unable to explain our findings and are reporting them to encourage others to investigate this phenomenon." If the results turn out to be real, she says, the implications are profound: we may have to rewrite physics and chemistry.