Fruit and Vegetable Intake and the Risk of Chronic Obstructive Pulmonary Disease: A Dose‐Response Meta‐Analysis of Observational Studies
Hongrui Zhai, Yu Wang, Wenjie Jiang
Abstract
Object . Results on the associations of fruit and vegetable intake with risk of chronic obstructive pulmonary disease (COPD) are still in conflict. Hence, we conducted a meta‐analysis to quantitatively evaluate the association between fruit and vegetable intake and the risk of COPD. Methods . PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) were searched for relevant studies published up to September 2019. Combined relative risks (RRs) and 95% confidence intervals (CIs) were calculated with the random effects model (REM). Dose‐response relationship was assessed by the restricted cubic spline model. Results . There are 8 studies involving 5,787 COPD cases among 244,154 participants included in this meta‐analysis. For the highest versus the lowest level, the pooled RR of COPD was 0.75 (95% CI, 0.68–0.84; I 2 = 46.7%) for fruits plus vegetables, 0.72 (95% CI, 0.66–0.79; I 2 = 1.3%) for fruits, and 0.76 (95% CI, 0.63–0.92; I 2 = 62.7%) for vegetables. In subgroup analysis of fruit plus vegetable intake and COPD risk, the inverse association exists in all three study designs. A nonlinear dose‐response relationship was found for COPD risk with fruit ( P non−linearity < 0.01). Conclusions . This meta‐analysis indicates that fruit and vegetable intake might be related to a lower risk of COPD.