Green tea consumption and hepatocellular carcinoma: a meta-analysis lacking evidence for a protective effect

Abstract

Aim: The association between green tea consumption and hepatocellular carcinoma (HCC) risk remains controversial. This meta-analysis aimed to quantify this association using rigorous epidemiological evidence. Methods: Six electronic databases (PubMed, Embase, Cochrane Library, SinoMed, CNKI, and Wanfang Data) were searched for studies published up to December 2025. Study quality was assessed using the Newcastle-Ottawa Scale, and only studies with a score ≥ 6 were included. Heterogeneity was quantified by I2, and pooled hazard ratio (HR) and odds ratio (OR) with 95% confidence intervals (CI) were calculated using random-effects models with the Hartung-Knapp-Sidik-Jonkman method. Subgroup analyses and meta-regression were conducted by study quality, tea type, region, sex, and dose, and by adjustment for 11 potential confounders, including hepatitis B virus and body mass index. Sensitivity analysis was performed using the leave-one-out method to assess the robustness of the pooled estimates. Publication bias was examined using funnel plots, Egger’s test, and Begg’s test. Results: Fifteen studies, including 8 cohort studies and 7 case-control studies, comprising 1,211,744 participants with 5,208 HCC cases, were eligible. For cohort studies, the pooled HR for HCC associated with tea consumption was 0.93 (95%CI: 0.69-1.25). For case-control studies, the pooled OR was 0.37 (95%CI: 0.10-1.39). Neither was statistically significant. Subgroup analyses showed no significant association for any examined factor, including study quality, tea type, sex, and dose. However, a statistically significant ass ociation was observed in the European subgroup (HR = 0.41, P = 0.0058), although this finding was based on a single study and should be considered exploratory. Leave-one-out sensitivity analysis confirmed the robustness of the findings. No obvious publication bias was observed. Conclusion: In the overall pooled analysis of cohort studies, current evidence, derived predominantly from East Asian populations, does not support a causative effect of tea consumption on HCC, although a modest protective effect cannot be completely ruled out based on the available data. Further rigorous studies are needed to clarify this relationship.