The impact of green tea consumption on the prevention of hemorrhagic stroke

Background: Different types of tea may have varying effects on the risk of hemorrhagic stroke, but previous studies have generated inconsistent results. We performed a nationwide, multi-center, case-control study to evaluate the association between the consumption of tea and the risk of hemorrhagic stroke. Methods: This study included 940 patients aged 30 to 84 with non-traumatic acute hemorrhagic stroke who did not have a history of stroke or hemorrhage-prone brain lesions, as well as 940 community controls and 940 hospital controls matched to each patient by age and gender. Pretrained interviewers obtained information on potential confounders. Consumption of tea was assessed by using a food frequency questionnaire. Participants were asked to indicate the number of cups of tea (green, black, and oolong tea) they consumed per day or per week during the preceding year. Results: The adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated by conditional logistic regression. The adjusted ORs of hemorrhagic stroke were 0.71 (95% CI: 0.59-0.87), 0.86 (95% CI: 0.55-1.37), and 1.34 (95% CI: 0.91-1.98) for consumption of green, oolong, and black tea, respectively, compared with no consumption. There was no significant linear trend for green tea consumption. Conclusions: Consumption of green tea may protect against hemorrhagic stroke, whereas consumption of black tea may have no meaningful effect on risk.