Farm pregnancy 'cuts asthma risk'
Published: 2008/08/30 22:58:02 GMT
BBC News
Living on a farm during pregnancy may help reduce the chance of the
child developing asthma, eczema and even hayfever, say scientists.
The New Zealand researchers suggest that exposure to animals and the
bacteria they carry may affect the foetus's immune system.
Writing in the European Respiratory Journal, they said exposure before
and after birth halved the risk.
But experts warn some animals carry infections which may harm the
baby.
The research, carried out at Massey University, adds to other studies
which have suggested that living on a farm, with regular contact with
animals, during the early years of life, could cut the risk of asthma
and other allergic diseases.
But the study of more than 1,300 farmers' children goes further,
suggesting that this protection could start building even before
birth.
It found that the greatest apparent protection - a 50% reduction in
asthma, and an even greater reduction in eczema and hay fever - was
gained by children whose mothers had been exposed to farm life during
pregnancy, and who currently lived on a farm.
The reasons why this might happen are unclear, although they are
likely to be related to the way that the child begins to develop its
immune system.
Milk bacteria
Living on a farm means frequent contact with animal bacteria, perhaps
through the consumption of unpasteurised milk, or contact with the
animals directly.
The researchers suggested that this might suppress the production of
particular immune cells linked to the development of asthma.
However, they suggested that while exposure during pregnancy might be
useful, it might only persist if the child was exposed after its birth
as well.
The findings are unlikely to lead to any change in current advice to
pregnant women, which urges caution about contact with certain farm
animals.
In particular, an infection which can cause miscarriage in pregnant
ewes can lead to the same result in humans.
The faeces of other animals can also carry infections which can affect
a pregnancy.
Dr Elaine Vickers, research manager at Asthma UK, said: "This study
adds to existing evidence sup****ting the hygiene hypothesis, which
states that early exposure to potential allergens results in a reduced
risk of asthma development.
"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."
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/7586328.stm
Published: 2008/08/30 22:58:02 GMT
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