Living on a farm protects from allergic rhinitis from childhood to early adulthood

Farm living confers a protective effect against allergic rhinitis that lasts from childhood to early adulthood, a new study has found.

Drawing from the phase II study GABRIEL, which looked at genetic and environmental correlates of asthma in a European community, researchers enrolled 1,333 participants (aged 6–11 years at baseline, 50 percent girls) who had accomplished the follow-up questionnaire. Aside from basic sociodemographic variables, factors of interest included farm contact and respiratory symptoms.

At baseline, symptoms of allergic rhinitis were significantly less common among participants who had lived on farms (4 percent vs 10 percent; p<0.001). The same was true for wheezing (8 percent vs 12 percent; p=0.02).

At follow-up, 66 percent of participants who were living on farms at baseline continued to do so; meanwhile, 3 percent had moved to farms by follow-up. The prevalence of allergic rhinitis jumped during the study duration, growing from 4 percent at baseline among farm dwellers to 10 percent at final assessment. During the same time, allergic rhinitis increased from 10 percent to 24 percent in those without farm contact.

Adjusted generalized estimating equations analysis revealed that symptoms of allergic rhinitis were over 60 percent less likely to develop in participants who had always lived on farms (odds ratio [OR], 0.35, 95 percent confidence interval [CI], 0.20–0.62), or those who initially did but moved out (OR, 0.36, 95 percent CI, 0.17–0.77).

Of note, “a nonsignificant interaction term between farm living and follow-up indicated that the protective effect of farm living on allergic rhinitis and wheezing stayed constant over time, regardless [of] whether participants had lived at the farm all the time or at baseline only,” the researchers said.

“In other words, after having lived on a farm in childhood, there was no additional benefit by staying on the farm vs having moved away from the farm,” they added.