Tea intake and non-alcoholic fatty liver disease risk: A two-sample Mendelian randomization study

Area of Science:

• Genetics
• Gastroenterology
• Nutritional Science

Background:

• Non-alcoholic fatty liver disease (NAFLD) poses a significant global health and economic burden.
• Tea consumption is widespread, yet its association with NAFLD risk remains unclear.
• Existing evidence on tea intake and NAFLD is inconsistent, necessitating further investigation.

Purpose of the Study:

• To investigate the potential causal relationship between tea intake and the risk of developing NAFLD.
• Utilize a two-sample Mendelian randomization (MR) approach to assess this association.
• Employ robust statistical methods to ensure reliable findings.

Main Methods:

• Selected 24 single-nucleotide polymorphisms (SNPs) strongly associated with tea intake as instrumental variables.
• Utilized summary-level genetic data for NAFLD from the FinnGen consortium (2,275 cases, 375,002 controls).
• Employed the inverse-variance weighted (IVW) method as the primary analysis, with MR Egger and weighted median for sensitivity analyses.

Main Results:

• Tea intake was not found to be causally associated with NAFLD risk (OR: 1.48; 95% CI: 0.64, 3.43; P=0.364).
• Sensitivity analyses and leave-one-out analyses confirmed the robustness of the findings.
• No significant evidence of heterogeneity, outliers, or horizontal pleiotropy was detected.

Conclusions:

• The study does not support a causal association between tea intake and a reduced risk of NAFLD.
• Findings suggest that tea consumption may not be a protective factor against NAFLD.
• Further research may explore other dietary factors or mechanisms influencing NAFLD.