Children born to women who live on a farm during pregnancy have a much lower risk of developing asthma, eczema and hay fever, according to New Zealand researchers who studied more than 1 300 farm children.
The researchers found that children who lived on farms and whose mothers lived on farms during pregnancy had a 50% reduction in asthma and an even greater reduction in eczema and hay fever, BBC NewsM reported.
Exposure to animals and the bacteria they carry may affect the developing foetus's immune system, including suppressing production of immune cells linked to asthma, the researchers suggested. They noted this beneficial effect may only persist if a child has the same type of exposure after birth.
"This study adds to existing evidence supporting the hygiene hypothesis, which states that early exposure to potential allergens results in a reduced risk of asthma development," said Dr Elaine Vickers, research manager at Asthma UK.
"However, the causes of asthma are still largely unknown and the processes involved in asthma development are incredibly complicated, including family history, environment and lifestyle."
The study was published in the European Respiratory Journal. – (HealthDay News, September 2008)
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