Tea consumption tied to reduced breast cancer risk with family history

  • Zhang D & al.
  • Int J Cancer
  • 13 Dec 2019

  • curated by Miriam Davis, PhD
  • Univadis Clinical Summaries
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Takeaway

  • 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.

Study design

  • 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.

Key results

  • 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.

Limitations

  • Observational design.