Green Tea Drinking and Breast Cancer Risk in Japanese Women
Author Information
Author(s): Iwasaki Motoki, Inoue Manami, Sasazuki Shizuka, Sawada Norie, Yamaji Taiki, Shimazu Taichi, Willett Walter C, Tsugane Shoichiro
Primary Institution: National Cancer Center, Japan
Hypothesis
Does high green tea intake reduce the risk of breast cancer?
Conclusion
The study found no association between green tea drinking and the risk of breast cancer.
Supporting Evidence
- The study included 581 breast cancer cases diagnosed during the follow-up.
- Women who drank five or more cups of green tea per day had an HR of 1.12 compared to those who drank less than one cup per week.
- No inverse association was found regardless of hormone receptor status.
- Follow-up lasted an average of 13.6 years.
Takeaway
Drinking green tea doesn't seem to help prevent breast cancer in women.
Methodology
The study followed 53,793 women over 13.6 years, assessing their green tea intake and breast cancer diagnoses.
Potential Biases
Potential for recall bias and unmeasured confounding factors.
Limitations
Self-reported green tea intake may lead to misclassification, and the number of breast cancer cases was relatively low.
Participant Demographics
Japanese women aged 40 to 69 years.
Statistical Information
Confidence Interval
95% CI 0.81 to 1.56
Digital Object Identifier (DOI)
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