Fruit and Vegetable Intake and the Risk of Chronic Obstructive Pulmonary Disease: A Dose-Response Meta-Analysis of Observational Studies

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) = 46.7%) for fruits plus vegetables, 0.72 (95% CI, 0.66–0.79; I(2) = 46.7%) for fruits plus vegetables, 0.72 (95% CI, 0.66–0.79; P(non−linearity) < 0.01). CONCLUSIONS: This meta-analysis indicates that fruit and vegetable intake might be related to a lower risk of COPD.