Authors: Campbell B, Raherison C, Lodge CJ, Lowe AJ, Gislason T, Heinrich J, Sunyer J, Gómez Real F, Norbäck D, Matheson MC, Wjst M, Dratva J, de Marco R, Jarvis D, Schlünssen V, Janson C, Leynaert B, Svanes C, Dharmage SC
Thorax. 2017 Mar;72(3):236-244
RATIONALE: Evidence has suggested that exposure to environmental or microbial biodiversity in early life may impact subsequent lung function and allergic disease risk.
OBJECTIVES: To investigate the influence of childhood living environment and biodiversity indicators on atopy, asthma and lung function in adulthood.
METHODS AND MEASUREMENTS: The European Community Respiratory Health Survey II investigated â¼10â 201 participants aged 26-54â years from 14 countries, including participants' place of upbringing (farm, rural environment or inner city) before age 5â years. A 'biodiversity score' was created based on childhood exposure to cats, dogs, day care, bedroom sharing and older siblings. Associations with lung function, bronchial hyper-responsiveness (BHR), allergic sensitisation, asthma and rhinitis were analysed.
MAIN RESULTS: As compared with a city upbringing, those with early-life farm exposure had less atopic sensitisation (adjusted OR 0.46, 95% CI 0.37 to 0.58), atopic BHR (0.54 (0.35 to 0.83)), atopic asthma (0.47 (0.28 to 0.81)) and atopic rhinitis (0.43 (0.32 to 0.57)), but not non-atopic outcomes. Less pronounced protective effects were observed for rural environment exposures. Women with a farm upbringing had higher FEV1 (adjusted difference 110â mL (64 to 157)), independent of sensitisation and asthma. In an inner city environment, a higher biodiversity score was related to less allergic sensitisation.
CONCLUSIONS: This is the first study to report beneficial effects of growing up on a farm on adult FEV1. Our study confirmed the beneficial effects of early farm life on sensitisation, asthma and rhinitis, and found a similar association for BHR. In persons with an urban upbringing, a higher biodiversity score predicted less allergic sensitisation, but to a lesser magnitude than a childhood farm environment.