Key 1999

Methods	Case‐control study within a cohort study in Japan
Participants	488,989 cohort participants 427 cases, sub‐cohort control
Interventions	N/A
Outcomes	Incidence Adjusted for age, residence at time of bombing and breast dose
Cancer type & time of follow‐up	Breast cancer (10 years follow‐up)
Sponsor	Japanese Ministry of Health and Welfare, US Department of Energy through National Academy of Science
Notes	≤ 1 cup green tea/day: RR = 1.00 2 to 4 cups green tea/day: RR = 1.02 (95% CI, 0.76 to 1.36) ≥ 5 cups green tea/day: RR = 0.86 (95% CI, 0.62 to 1.21) p = 0.284