Does drinking tea prevent age-related macular degeneration? A cross-sectional and Mendelian randomization analysis
Bo Li, Yikeng Huang, Yuqian Guo, Qing Yang, Ningyao Cao, Weirong Xu, Jingjing Cui, Fei Xue, Yi Gu, Wenwen Xia, Xinyu Zhang, Xiaoqian Wu, Yujin Jiang, Fei Chen, Linna Lu, Chuandi Zhou, Yong LiPurpose
The potential protective effect of tea consumption on age-related macular degeneration (AMD) remains controversial. This study aims to investigate the association between tea consumption and AMD in a population-based cross-sectional analysis and evaluated causality using Mendelian randomization (MR), with external validation in an independent cohort.
Design/methodology/approach
A cross-sectional study combined with MR and external validation. The study included 2,328 adults aged ≥ 40 years from the National Health and Nutrition Examination Survey 2005–2006, including 227 participants with AMD. A multivariable logistic regression model was constructed to examine the association between tea consumption and AMD after adjustment for potential confounders. In a two-sample MR analysis, the authors analyzed summary-level data on tea consumption from the UK Biobank (447,485 cases) alongside published AMD genome-wide association study data (14,034 cases, 91,214 controls). External validation was conducted in 22,901 randomly selected adults aged ≥ 50 years from the community health service centers in Shanghai.
Findings
In the cross-sectional data, no significant dose-response relationship between tea consumption and AMD was observed (no tea consumption vs. 0–1 cup/day vs. > 1 cup/day: 8.8%, 7.5%, 8.0%, p = 0.74). Furthermore, multivariate logistic regression analysis indicated that, compared to non-tea-drinking, the odds ratios (ORs) for AMD in the 0–1 cup/day and > 1 cup/day groups were 1.146 (p = 0.51) and 1.098 (p = 0.75), respectively. In the inverse variance-weighted MR analysis, no causal relationship was found between tea consumption and AMD (OR = 1.21, 95% Confidence Interval [CI]: 0.91–1.62, p = 0.18). In external validation, the prevalence of AMD was 6.7% among tea-drinking group, which was comparable to that of non-tea-drinkers (6.9%, p = 0.64).
Originality/value
Drinking tea does not reduce the risk of AMD. No causal relationship between tea consumption and AMD could be established.