Consumption of fruit and vegetables might mitigate the adverse effects of ambient PM_2.5 on lung function among adults

Background Evidence on the effects of ambient PM_2.5 on lung function is limited among adults and the effect modification by dietary fruit and vegetables remains largely unknown. Methods We interviewed 29,032 participants aged 50 years and older from the WHO Study on global AGEing and adult health. Annual average PM_2.5 levels were estimated for each community using satellite data. We applied multi-level linear regressions to examine the association between ambient PM_2.5 and lung function (forced vital capacity (FVC), forced expiratory volume in 1-sec (FEV₁), FEV₁/FVC ratio, peak expiratory flow (PEF), and forced expiratory flow between 25th and 75th percentiles of FVC (FEF_25–75)). Results We found that ambient PM_2.5 was associated with lower lung functions. Each 10 μg/m³ increase in PM_2.5 corresponded to reductions of 123.58 ml in FVC (95% CI: −185.21, −61.95), 126.64 ml in FEV₁ (95% CI: −186.04, −67.23) and 178.93 ml/s FEV_25–75 (95% CI: −249.20, −108.66). Lower effect estimates were observed among those with higher consumption of fruit and vegetables. Conclusion Our study suggests that exposure to ambient PM_2.5 might be one risk factor of reduced lung function in adults and that higher consumption of fruit and vegetables may mitigate this effect.