How Might Farming Confer Asthma Protection?

Children who grow up on farms, have older siblings, or have furry pets in their homes all seem to have lower risk for atopic diseases. Two U.S. farming communities, the Amish of Indiana and the Hutterites of South Dakota, have similar genetic backgrounds but different farming practices; the Amish still live on traditional single-family dairy farms, whereas the Hutterites practice large-scale mechanized farming. In previous studies, Amish schoolchildren had lower prevalence of asthma (5% vs. 21%) and allergic sensitization (7% vs. 33%) compared with Hutterite schoolchildren. In the current study, researchers explored what immunological mechanisms might account for this difference.

Immunological and genetic testing was performed in 30 randomly…