Effect of Farming on Asthma.

In this review, we discuss an immunobiology model of farm exposure towards the protective effect of asthma. Unraveling the protective effect of farming exposure could help develop novel strategies to prevent asthma. Asthma is a chronic airway inflammation that causes coughing, wheezing, chest tightness or shortness of breath. The reasons for the increase in the prevalence of asthma worldwide is still unclear but has been hypothesized to be attributable to westernization/urbanization of rural regions thus resulting in the loss of rural farming environmental. In this review we discuss the effect of the environmental factors, specifically farming, on the risk of asthma in children. Here, we will summarize the main findings of 27 studies related to 11 different cohorts. Several studies have shown preventive effect of traditional farming on the prevalence and incidence of asthma in childhood. Furthermore, consumption of unpasteurized cow's milk, exposure to farm animals as well as fodder have been shown to have a protective effect on asthma. The precise mechanism of the protective effect is still unclear. There are assumptions, that maternal/childhood exposures to farm animals result in higher microbial exposures through which the protective effect might be mediated. Also, consumption of unpasteurized milk (when consumed during pregnancy by mother or early childhood by children) can modulate cytokine production patterns which could be responsible for the observed protective effect.
CONCLUSION: This review provides evidence of the protective effect of farming environment i.e., exposure to farm animals, their fodder as well as consumption of unpasteurized cow's milk suggesting that novel strategies could be developed to prevent asthma.