According to a new international study, people who spent their first five years of life on a farm suffered from fewer allergies as adults and had stronger respiratory systems.
Women, in particular, had significantly stronger lungs as adults if they lived out their childhood on a farm. The findings of the study were published in the journal Thorax.
Who conducted the study?
A team of researchers from the University of Melbourne, led by Professor Shyamali Dharmage, evaluated more than 10 000 individuals aged between 26 and 54 from 14 different countries to find out whether they had grown up on a farm, in a small town, in a large city, or in a inner city with the purpose of seeing how it relates to health. 
The number of siblings and pets, when they started school or pre-school, and other health and lifestyle factors were taken into account. Lung strength, the levels of antibodies, and self-reported allergic symptoms were also tested and factored in.
What were the results?
It was found that almost 1 in 10 or 9.2% of people had lived on a farm before the age of 5, with 27% growing up in inner cities. 64% of participants said that they grew up in small town, city suburb or rural village.
Those who grew up on a farm were more likely to have had older siblings and pets, as well as having had to share their bedroom with a sibling in early childhood. It was found that they were also less likely to have had a relative, such as a parent, with allergies.
The adults who had grown up on farms before the age of 5 had fewer allergies, including 57% less sinus symptoms and were found to be 54% less likely to have hay fever or asthma than those who had grown up in inner cities.
There was also a 50% reduction in asthma occurrences and an overall of 47% more tolerance to allergens in those who grew up on farms compared to those who did not.
What is the reason? 
The authors of the study said: “Consistently across 14 countries, this analysis shows that early-life exposure to farm environments is protective against subsequent adult allergic diseases. The consistency of the findings across multi-country settings suggests that farming effects may be due to biological mechanisms rather than socio-cultural effects that would differ between countries. 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.”
While researchers are still unsure of exactly how farm-life increases the tolerance to allergies, they have speculated that the increase in physical activity, exposure to microbes and being in purer, cleaner air could be the reason.
Until now, few studies have ever been able to associate adulthood allergies to where children were raised, a finding which is making “the farm effect” more than fiction.
Sources:
https://www.thejournal.ie/children-farm-allergies-2998440-Sep2016/
https://www.communitycounselingservices.org/poc/view_doc.php?type=news&id=184456&cn=72
