Background: A large number of studies have consistently shown that children growing up on a farm have a reduced prevalence of allergic disorders. The GABRIEL Advanced Study was conducted in five rural areas of southern Germany, Switzerland, Austria and Poland to shed light on the protective 'farm effect' on asthma and atopic disease. Whereas, the GABRIEL Advanced Study focussed on rural children only, the present study incorporates data from Innsbruck town children also.
Methods: A screening questionnaire was developed to identify children with and without atopic disease within their living environment. Children were stratified into farm children, rural children and Innsbruck-town children. Within the farming environment, regular exposure to the following key factors of interest was predefined: the animal shed, the hay loft and farm milk. Wheezing in the past 12 months (W12), doctor-diagnosed (dd)-asthma, dd-allergic rhinitis and dd-atopic dermatitis were evaluated by using standardized questions from the International Study of Asthma and Allergies in Childhood (ISAAC) RESULTS: Farm children with regular exposure showed a lower risk for W12 (odds ratios (OR) = 0.3; 95%; confidence interval (CI) 0.2-0.5), dd-asthma (OR = 0.4; 95% CI 0.2-0.9) and dd-hay fever (OR 0.2; 95% CI 0.1-0.4). The protective effect of regular exposure extended to rural children but included W12 and dd-hay fever only. Multivariate logistic regression analysis for children being regularly exposed revealed protective attributes for the animal shed, the hay loft and farm milk.
Conclusion: These data show that regular exposure to a farming environment protects against wheezing, asthma and hay fever. Regarding wheezing and hay fever, this effect was not restricted to children living on a farm but also notable in rural children with regular farm contact.