Purpose: This study examined the association between cumulative tea consumption over time and various colorectal adenomas as well as their pathology, number, and size. Methods: 7355 eligible subjects who underwent health check-ups with colonoscopies were recruited. They were classified into three groups: polyp-free, having low-risk colorectal adenomas, and having high-risk colorectal adenomas. The adenoma pathology, number, and size were collected. We defined 120 mL for each Chinese traditional teapot as a ‘cup’, and calculated the average daily cups of tea consumed. A ‘cup-year’ was defined as the daily cups multiplied by the years of tea consumption and was used to express the cumulative amount of tea consumption over time. Results: Compared to those with no habitual tea consumption, the lowest, middle, and highest tertiles of tea consumption were found to be inversely related to low-risk colorectal adenomas. For high-risk colorectal adenomas, a negative association was found only in the group with the highest tertile of tea consumption. An inverse association between the highest tertile of tea consumption and various features of high-risk colorectal adenomas was also found for villous-rich adenomas and the presence of three or more adenomas, but was not found to be related to adenoma size ≥1 cm. Conclusion: Tea drinking was inversely associated with both low-risk and high-risk colorectal adenomas. Only a larger cumulative dose of ≥42 cup-years was negatively associated with high-risk colorectal adenomas, especially adenomas with villous-rich pathology and when three or more adenomas were present.
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