• Living on a farm in early childhood is linked to a lower risk of allergies as an adult, and stronger lungs in women. (LightRocket/Getty Images)
A new study from the University of Melbourne has linked living on a farm in early childhood to having a lower risk of allergies in adulthood.
By
SBS Life

27 Sep 2016 - 5:10 PM  UPDATED 28 Sep 2016 - 10:02 AM

Children who grow up on a farm are less likely to develop allergies as adults, compared to those who spend their early childhood in a rural village or urban area, according to research from University of Melbourne, released today.

The new study, published online in the journal Thorax, also finds that living on a farm could help girls grow into women with stronger lungs.

These two health outcomes were consistent across Australia and 13 other countries studied throughout Europe and Scandinavia between 1998 and 2002.

Authors say this shows that farming effects may be due to biological mechanisms rather than socio-cultural effects that would differ between countries.

Farm kids were also 50 per cent less likely to have allergic or non-allergic asthma than any of the other groups. 

“This analysis shows that early life exposure to farm environments is protective against subsequent adult allergic diseases,” the study reads.  

“A novel finding was that women who grew up on a farm had higher lung function, and only mild heterogeneity was observed across 14 countries.”

The study marks the first to report beneficial effects of growing up on a farm on adult obstructive and restrictive lung disease.

It also highlighted that various factors that would reduce an inner city dweller’s risk – having pets and siblings in day care – were not as strong as the protective effects of a farm upbringing.

Farm kids were also 50 per cent less likely to have allergic or non-allergic asthma than any of the other groups.

Do kids grow out of childhood asthma?
Asthma affects children in different ways.

Various theories have been suggested to explain the sharp rise in the prevalence of asthma and allergies over the past few decades, with recent research pointing to early childhood exposure to a wide variety of potential allergens and microbes as possibly protective – the so-called hygiene hypothesis.

But it’s not clear whether growing up in any one type of environment is key or whether it’s the diversity of microbes a child is exposed to early on that might count.

To find out, the researchers drew on the European Community Respiratory Health Survey II, which included more than 10,000 people aged 26 to 54 from 14 countries in Europe, Scandinavia, and Australia between 1998 and 2002.

Participants were asked where they lived before the age of five – on a farm; in a country village; in a small town or city suburb; or inner city.

A ‘biodiversity score’ from zero to five was calculated for each of them, based on their reported exposure to pet cats and dogs; older siblings; other kids in day care/nursery/ school; and how many other children they shared a bedroom with.

Their lung strength and antibody (IgE) levels were tested and they filled in a questionnaire on allergic symptoms, including nasal symptoms, asthma, hay fever, wheeze, and bronchial hyper-responsiveness (over reactive airways).

As adults, farm kids were less likely to be sensitised to allergens, have nasal symptoms, or to have over reactive airways than those living in any other environment.

The researchers found that kids who grew up on a farm were more likely to have had pets, older siblings, and to have shared a bedroom in their early childhood. And a family history of allergy was less common in this group.

As adults, farm kids were less likely to be sensitised to allergens, have nasal symptoms, or to have over reactive airways than those living in any other environment.

They were also 54 per cent less likely to have asthma or hay fever and 57 per cent less likely to have allergic nasal symptoms than those living in an inner city.

“Our study confirmed the beneficial effects of early farm life on sensitisation, asthma and rhinitis, and found a similar association for bronchial hyper responsiveness.

“In persons with an urban upbringing, a higher biodiversity score predicted less allergic sensitisation, but to a lesser magnitude than a childhood farm environment.”

Those living in a village, town or city suburb before the age of 5 were only slightly less likely to have asthma or hay fever as an adult, and no less likely to have allergic nasal symptoms than those living in an inner city before the age of 5.

The authors say more research is needed to determine why gender influences asthma.