Tea Consumption and Liver Cancer: A Population-Based Case-Control Study in Eastern China.

Background/Objectives: Identifying dietary factors influencing liver cancer is crucial for developing preventive measures. While tea polyphenols have demonstrated cancer-preventive activities in animal models, the evidence in humans is not definitive. This study aims to explore the association between tea consumption and liver cancer, as well as the interaction between tea drinking and other risk factors, in China, a country with a high incidence of liver cancer and substantial tea consumption. Methods: A population-based case-control study was conducted in Jiangsu Province from 2003 to 2010. Socio-demographic data, history of tea consumption, and serum markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were evaluated. Unconditional logistic regression was used to examine the associations between tea consumption and the odds of liver cancer. Potential interactions between tea consumption and other major liver cancer risk factors were assessed. Results: A total of 2011 incident liver cancer cases and 7933 controls were included in the analysis. Regular tea drinking showed an inverse association with the risk of liver cancer compared with those who never drank tea (OR: 0.79; 95% CI: 0.63-0.99). Current tea drinking showed an inverse association with liver cancer (OR: 0.51; 95% CI: 0.39-0.66), while former tea drinking showed a positive association (OR: 3.56; 95% CI: 2.42-5.23). Current tea consumption was inversely associated with liver cancer incidence among both hepatitis B surface antigen (HBsAg) positive (OR: 0.45; 95% CI: 0.28-0.73) and HBsAg negative participants (OR: 0.51, 95% CI: 0.36-0.73), among both never and ever tobacco smokers, ever alcohol drinkers (OR: 0.46; 95% CI: 0.33-0.63), and among those without family history of liver cancer. Multiplicative and additive interactions were observed between tea drinking and HBsAg, alcohol consumption, and history of raw water drinking. Conclusions: Tea consumption is inversely associated with the development of primary liver cancer, with potential interactions involving HBV infection, alcohol consumption, and raw (unsafe) water drinking. Increasing tea consumption-particularly among high-risk populations such as individuals who consume alcohol-may serve as an additional preventive measure for liver cancer. This should be considered alongside established strategies, including HBV vaccination, alcohol cessation, and avoidance of drinking raw water, to help reduce liver cancer risk.