Objective: To explore the role of green tea in decreasing the risks of gastric cancer, liver cancer, esophageal cancer among alcohol drinkers or cigarette smokers.
Methods: A population based case-control study was conducted in Taixing, Jiangsu province.
Results: In Taixing city, identified cases of stomach, liver and esophageal cancers were chosen with informed consent. The numbers were 206, 204, 218 respectively. Controls were chosen from normal population having lived in the area for longer than 10 years, also with informed consent. Green tea drinking seemed to have decreased 81%, 78%, 39% risk for the development of gastric cancer, liver cancer and esophageal cancer among alcohol drinkers. It might also have decreased 16%, 43%, 31% on the risks of developing the three kinds of cancers among cigarette smokers. Interaction assessment showed that drinking green tea could significantly decrease the risk of gastric cancer and liver cancer among alcohol drinkers, with ORs of interaction item 0.23 (95% CI: 0.10 - 0.55) and 0.25 (95% CI: 0.11 - 0.57) respectively.
Conclusion: Habit of drinking green tea seemed to have significant protective effects on the development of both gastric and liver cancer among alcohol drinkers while, green tea also having some protective effect on esophageal cancer among alcohol drinkers and on three kinds of cancers among cigarette smokers.