Science - February 3, 2010

Piglets benefit from homeopathy - or do they?

Fewer piglets with diarrhoea after injection with homeopathic medicine.
Professor Savelkoul has reservations about the study.

Antibodies in the mother's milk have very little effect on porcine diarrhoea
A homeopathic treatment of pregnant sows leads to a substantial reduction in the piglets' chance of getting diarrhoea. This discovery was made by Irene Camerlink of the Biological Farming Systems Chair Group. She published her findings last month in the journal Homeopathy.
 Camerlink used a homeopathic medicine, based on a variant of the E. coli bacterium that causes diarrhoea, to treat 26 pregnant sows as an alternative to using antibiotics for diarrhoea in piglets. A second group of 26 pregnant sows was given a placebo. Homeopathic medicines are diluted to such an extent that there are virtually no molecules of the active component left. The theory is that the active component transfers its functionality to the solvent.
The results are striking. 'Only four per cent of the piglets that had been treated had diarrhoea', explains the researcher. 'That figure was nearly twenty-five per cent for the control group.'
Professor Huub Savelkoul of the Cell Biology and Immunology Group is critical: 'There are cases of homeopathic medicines where the clinical effectiveness has been proven but there is not a single account of the physiochemical and biological mechanisms that would give a scientific explanation of homeopathy.' What is more, he finds the idea of homeopathy illogical. 'If our bodies continually had to react to such 'absent compounds' there would be no end to it; you would simply lose far too much energy', thinks Savelkoul.
Mother's milk
He says that one of the problems in the pig study is the mechanism describing how the homeopathic medicine works.  'The researchers assume that the treatment of the sows compensates for the reduced numbers of antibodies in the mother's milk during the first pregnancy. This is supposed to result in the piglets suffering less from diarrhoea', says Savelkoul. 'However, antibodies in the mother's milk have very little effect on this form of porcine diarrhoea - a far more important factor is the piglet's congenital defence mechanism.'
But why, then, do the researchers find an effect for the treatment? Savelkoul points to the relatively small number of sows used in the study. 'What is more, the 26 sows per group were subdivided into four subgroups based on when they were due to give birth', he said. 'That leaves very few animals per group.' According to Savelkoul it would have been better to have more sows in the study and restrict the number of piglets. 'There are big differences in stress as well as in immune response within the group of sows from which the researchers selected their 52 sows. They will pass those characteristics on to the piglets', Savelkoul explains. 'As a result, the researchers are running a risk of having an unequal distribution in the small subgroups of sows they have been using.' Another point of principle he notes is that the sows were not allocated to the treatments using a blind procedure.
Not random chance
Camerlink thinks it is a pity that science is not open to new alternatives to antibiotics. She says it cannot be because of the number of sows. 'The period in which the sows gave birth had no effect on the incidence of diarrhoea, which means the animals could be considered as one group', claims the researcher. 'The number of animals we used was actually more than the required number.' The researcher does not think the positive outcome is the result of random chance: the homeopathic medicine is now being used successfully on the farm where the experiment was carried out, replacing the standard E. coli vaccination they used to use.