Environment and Breast Cancer: Science Review
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The Effects of Green Tea Consumption on Incidence of Breast Cancer and Recurrence of Breast Cancer: A Systematic Review and Meta-analysis
Seely, D., Mills, E. J., Wu, P., Verma, S., Guyatt, G. H. Integr Cancer Ther. 2005. 4:2, 144-55.
Topic area
Diet - No
Diet - No
Study design
Meta-analysis
Meta-analysis
Funding agency
Lotte and John Hecht Memorial Foundation
Lotte and John Hecht Memorial Foundation
Study Participants
Number of Cases
925 (includes men and women)
925 (includes men and women)
Menopausal Status
The menopausal status of women included in this study is listed here.
Premenopausal and postmenopausal combined
Number of Controls
115,601 (includes men and women)
115,601 (includes men and women)
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Observational or randomized trials (though none existed) examining the effect of great tea consumption on breast cancer incidence or recurrence in men and women of all age. Ex: If studies did not not look specifically at green tea.
Comment about participation selection
Strong methodology for meta-analysis
Strong methodology for meta-analysis
Exposure Investigated
Exposures investigated
Green tea
Green tea
How exposure was measured
Questionnaire
Questionnaire
Exposure assessment comment
Measurements will vary between studies.
Measurements will vary between studies.
Statistical Analysis
Breast cancer outcome investigated
Primary breast cancer
Primary breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
None
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Not considered: Menopausal status, family history of breast cancer, parity
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
No
Description of major analysis
Pooled RR and 95% CI
Pooled RR and 95% CI
Strength of associations reported
0.89 (0.71 - 1.10)
0.89 (0.71 - 1.10)
Results Comments
The pooled analysis does not definitively support the use of green tea in primary prevention of breast cancer; however, a trend toward risk reduction is demonstrated in nearly all the case-control and cohort studies.
The pooled analysis does not definitively support the use of green tea in primary prevention of breast cancer; however, a trend toward risk reduction is demonstrated in nearly all the case-control and cohort studies.
Author address
Department of Clinical Epidemiology, Canadian College of Naturopathic Medicine, Toronto, Ontario, Canada, Institute of Medical Science, University of Toronto, Ontario, Canada. dseely@ccnm.edu.
Department of Clinical Epidemiology, Canadian College of Naturopathic Medicine, Toronto, Ontario, Canada, Institute of Medical Science, University of Toronto, Ontario, Canada. dseely@ccnm.edu.