Kurahashi 2007

Methods	Case‐control study within an prospective cohort study in Japan
Participants	49,920 cohort participants 404 cases, sub‐cohort control
Interventions	N/A
Outcomes	Incidence Adjusted for age and residence
Cancer type & time of follow‐up	Prostate cancer (follow‐up 11 to14 years)
Sponsor	By a grant‐in‐aid for cancer research from the Ministry of Health, Labour and Welfare, Japan for the Third Term Comprehensive 10‐year strategy for cancer control and by grants‐in‐aid for scientific research on priority areas form the Ministry of Education, Culture, Sports, Science and Technology for research on the risk of chemical substances.
Notes	<1 cup/day: RR 1.00 1 to 2 cups/day: RR 1.12 (95% CI, 0.65 to 1.94) 3 to 4 cups/day: RR 0.86 (95% CI, 0.50 to 1.47) ≥ 5 cups/day: RR 0.60 (95% CI, 0.34 to 1.06) p = 0.03