Zhang 2007.

Study characteristics
Methods	HCC in China
Participants	Participants: 1009 cases and 1009 controls (all women) Inclusion criteria: aged 20‐87 years, newly diagnosed with invasive ductal carcinomas or in situ carcinoma of the breast, residents in Hangzhou, Zhejiang Province, China Recruitment: from July 2004‐September 2005
Interventions	N/A
Outcomes	Number of cases Breast cancer: 1009 cases (all female)
Green tea in exposure categories	Exposure assessment: intake of green tea Lowest exposure: never or seldom Intermediate exposure 1: ≤ 1 cup/week Intermediate exposure 2: 2–6 times/week Intermediate exposure 3: 1 cup/d Highest exposure: ≥ 2 cups/d
Notes	Funding: not declared Statistical methods: conditional logistic regression Variables controlled in analysis: resident area, education, BMI, age at menarche, number of children breastfed, menopausal status, oral contraceptive use, HRT, biopsy‐confirmed benign breast diseases, breast cancer in first‐degree relatives, total energy intake, passive smoking, alcohol consumption, coffee consumption, physical activity, soy intake, vegetable intake and fruit intake Variables controlled by matching: age (± 5 years) Zhang 2009 reports same data as Zhang 2007 but stratified by intake of mushrooms.