Green tea and black tea consumption in relation to colorectal cancer risk: the Singapore Chinese Health Study

D ow nloaded from The relationships between green tea and black tea consumption and colorectal cancer risk were examined within the Singapore Chinese Health Study, a prospective cohort study of diet and cancer involving over 60,000 men and women. Intake of green tea and black tea was assessed through in-person interviews. Incident cancer cases and deaths among cohort members were identified through record linkage of the cohort database with respective databases from the nationwide Singapore Cancer Registry and the Singapore Registry of Births and Deaths. The proportional hazard regression method was used to examine the associations between intake of green and black tea separately and colorectal cancer risk with adjustment for potential confounders. After an average of 8.9 years of follow-up, 845 colorectal cancer cases were identified. Subjects who drank green tea exhibited a statistically non-significant increase in risk (RR = 1.12, 95 % confidence interval (CI) = 0.97-1.29) relative to nondrinkers of green tea. Thi