- Green or black tea consumption is associated with up to 18% lower risk for breast cancer.
- Results are from an analysis of the Sister Study, a large prospective cohort of breast cancer-free women whose sisters have breast cancer.
Why this matters
- Preclinical studies suggest that black and green tea have chemopreventive qualities.
- Results from other cohorts have been inconsistent, in part because they lumped together all types of teas.
- The results of this study suggest that a randomized controlled trial is warranted.
- Prospective cohort of 45,744 US and Puerto Rican women in the Sister Study, followed for a median of 8.6 years.
- Tea consumption was assessed by Food Frequency Questionnaire at enrollment, covering previous 12 months.
- Breast cancer diagnoses were assessed by follow-up questionnaires and verified by medical record review.
- Funding: NIH.
- 81.6% drank black tea and 56.0% green tea.
- 2809 breast cancers were diagnosed during follow-up.
- Inverse associations were found between 2 tea types and breast cancer:
- Black tea (≥5 vs 0 cups/week): aHR, 0.88 (95% CI, 0.78-1.00).
- Green tea (≥5 vs 0 cups/week): aHR, 0.82 (0.70-0.95).
- Results did not vary by estrogen receptor status, menopausal status, or BMI.
- Observational design.