Fruit Intake and Respiratory Health: Results from Mendelian Randomization

Abstract

Abstract Background Respiratory disease contributes to a substantial burden of disease and mortality. It continues to impact human health and the quality of life under the continuous advancements in prevention and treatment. As reported by previous research, dietary factors might be regarded as latent risk factors for lung disease, suggesting that a vegetarian diet can effectively reduce mortality. Methods In this study, genome-wide association studies (GWAS) were used to conduct Mendelian randomization (MR) analyses to explore the causal effect of fruit intake on respiratory disease burden including chronic obstructive pulmonary disease, bronchitis, emphysema, and asthma. MVMR was carried out to validate the results under the influence of the other kind of fruit intake. Results There was weak evidence for a possible causal relationship between fresh fruit intake and respiratory diseases, whereas a substantial and strong causality was found between dried fruit intake and the four outcomes (COPDIVW: OR (95% CI) = 0.32 (0.22, 0. 48), P value < 0.001; asthmaIVW: OR (95% CI) = 0.59 (0.44, 0.79), P value < 0.001; bronchitisIVW: OR (95% CI) = 0.50 (0.35, 0.73), P value < 0.001; emphysemaIVW: OR (95% CI) = 0.15 (0.05, 0.42), P value < 0.001), with stability confirmed by tests and MVMR. Conclusions Our study strengthens the evidence for a positive causal relationship between dried fruit intake and four common respiratory outcomes but fails to show an association between fresh fruit intake and the outcomes, and the reliability of the dietary intervention could be strengthened by further validation.