The finding, from a study of almost 300 children who followed the anthroposophic lifestyle advocated by the Swedish spiritual leader Rudolf Steiner, adds to evidence that aspects of modern lifestyles are to blame for the startling rise in allergies around the world in the past 20 to 30 years.
One in three children in industrialised countries has an allergic disorder in what is now recognised to be a modern epidemic. Asthma, hay fever and eczema are the commonest allergies. They have more than doubled in recent decades but experts remain baffled by the extent and speed of their rise.
Pollution, infection and changes to the diet have been suggested as causes but hard evidence has been lacking. A growing body of evidence is pointing to the cleanliness associated with modern lifestyles, which protects children from bacteria and infection but at the same time prevents them developing natural resistance, as the principal cause.
In the latest study, published in The Lancet, 295 children aged 5 to 13 attending Rudolf Steiner schools near Stockholm, Sweden, were compared with 380 children of the same age at neighbouring schools. Tests showed the Steiner children had 38 per cent less atopy (sensitivity to allergic triggers such as pollen or house-dust mites) than the others.
Only half the Steiner children had ever taken antibiotics and just 18 per cent had had the MMR (measles, mumps and rubella) vaccination compared with over 90 per cent of children in the other schools. Almost two-thirds of the Steiner children ate fermented vegetables, containing live lactobacilli also found in some yoghurts said to aid digestion, compared with less than 5 per cent at the other schools.
Dr Johan Alm and colleagues from the Karolinska Institute in Stockholm suggest that their finding could help to account for the recent rapid rise in allergies. They say: "Lifestyle factors related to the anthroposophic way of life appear to lessen the risk of atopic disease in childhood. Since that way of life involves several characteristics that were more common in the general population some decades ago, our study may help to explain the recent increase in atopy."
In a commentary, Professor David Strachan of St George's Hospital Medical School, London, says the Swedish study adds to evidence that allergies are less common in people with simple lifestyles. However, he says the value of the study is limited because it is impossible to gauge the relative importance of the various lifestyle features - diet, incomplete immunisation (Steiner children tend to have vaccinations only against tetanus and polio and to have them later than officially recommended), and restricted use of antibiotics.
The strongest evidence shows that children in large families, exposed to many infections at a young age, are less likely to develop allergies than children from smaller families raised in "cleaner" environments. Professor Strachan says the "hygiene hypothesis" remains the best "because it offers a unifying explanation for the striking variations in prevalence of allergic disease".Reuse content