Koizumi 2003

Methods	Pooled analysis of 2 population‐based prospective cohort studies in Japan
Participants	Cohort I: 31,345 participants Cohort II: 47,605 participants 733 cases, sub‐cohort control
Interventions	N/A
Outcomes	Incidence Adjusted for gender, age, type of health insurance, parental history of gastric cancer, history of peptic ulcer, smoking, alcohol, tea consumption and that of other food (e.g. rice, pickled vegetables)
Cancer type & time of follow‐up	Gastric cancer (follow‐up cohort I: 9 years, cohort II: 7 years)
Sponsor	Not declared in this paper but in Tsubono 2001 ‐ Supported in part by grants from the Japanese Ministry of Health and Welfare and the Japanese Ministry of Education, Science, and Culture.
Notes	<1 cup/day: RR 1.00 1 or 2 cups/day: RR 1.01 (95%, CI 0.8 to 1.27) 3 or 4 cups/day: RR 0.89 (95%, CI 0.7 to 1.13) ≥5 cups/day: RR 1.06 (95%, CI 0.86 to 1.3) p = 0.61