Tea consumption and risk of lung diseases: a two‑sample Mendelian randomization study

BACKGROUND: Numerous studies have reported the association between tea intake and lung diseases. However, the probable relationship between tea consumption on lung diseases still remain controversial and it is unclear whether these findings are due to reverse causality or confounding factor. METHODS: In order to systematically investigate the causal connection between tea intake on respiratory system disorders, we employed a two-sample Mendelian randomized (MR) study. Genetic instruments for tea intake were identified from a genome-wide association study (GWAS) involving 447,385 individuals. Data on lung diseases were collected from a variety of publicly available genome-wide association studies. The main method used for MR analysis is the inverse variance weighting (IVW) method. To ensure the accuracy of the findings, further sensitivity analysis was conducted. RESULTS: The IVW method in our MR analysis revealed no evidence to support a causal relationship between tea intake and lung diseases (IPF: OR = 0.997, 95% CI = 0.994-1.000, p = 0.065; Lung cancer: OR = 1.003, 95% CI = 0.998–1.008, P = 0.261; COPD: OR = 1.001, 95% CI = 0.993–1.006, p = 0.552; acute bronchitis: OR = 0.919, 95% CI = 0.536–1.576, p = 0.759; tuberculosis: OR = 1.002, 95% CI = 0.998–1.008, p = 0.301; pneumonia: OR = 0.789, 95% CI = 0.583–1.068, p = 0.125). The reliability of the results was further demonstrated by four additional MR analysis techniques and additional sensitivity testing. CONCLUSION: We found no evidence of a link between tea intake on lung diseases in our MR results based on genetic information. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12890-023-02762-4.