One surprising advantage farm kids have over city kids

Wednesday, September 9, 2015, 1:35 PM - Growing up on a farm, specifically dairy farms, reduces the chances of developing allergy and asthma complications, according to new a study.

The research published recently in the journal Science, finds in children, allergic sensitization and asthma are strongly influenced by genes and the environment.

A dairy farm is one of the strongest protective environments due to high-level exposure to Lipopolysaccharides (LPS), also known as endotoxin, a cell wall component of Gram-negative bacteria.

In order to test whether exposure to endotoxin and protection from allergy are related, researchers exposed mice to a low dose every other day for two weeks.

The mice were able to develop a protein called A20 when exposed to farm dust. The study found the allergy-preventer doesn't affect the immune system, it influences the structural cells that make up the lining of the lung.

Once the researchers removed A20 from the lungs of mice, the farm dust stopped protecting the rodents from allergic reactions.

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The research is linked to medical term hygine hypothesis, which argues a lack of early childhood exposure to infectious agents, microbes and symbiotic microogranisms (e.g. gut flora or probiotics), increases the susceptibility to allergic diseases by suppressing the natural development of the immune system.

There is increasing evidence of what researchers coin the "farm effect." While low allergy and asthma rates are found among children living on farms in central Europe, less is known about the influence of growing up on North American farms, according to Reuters.

Researchers found in the Journal of Allergy and Clinical Immunology that only 25 per cent of children living on Swiss farms reacted to common allergens such as dust mites, pollen and mold, while about 45 per cent of kids in the general population reacted. Notably, Amish children raised on rural farms in northern Indiana, were 8 per cent or less prone to react to allergens.

In addition to testing mice, researchers tested 2,000 people who lived on farms and it was discovered that their environment didn't play a role, rather it was a mutation related to the gene A20.

"A20 was not a coincidence, it was really necessary," Bart Lambrecht of Ghent University, who co-led the study told the Washington Post. "This is linking, showing a cause and effect link, between exposure to farm dust and fewer allergies. I think our study is a big step forward."

Lambrecht and his colleagues hope the cells of the lung will gain more attention in allergy research, noting this could be a sign, "allergy and asthma vaccines need to be administered by aerosol instead of injection in order to truly be effective."

Source: Washington Post | Study | Reuters