Plasma tea polyphenol levels and subsequent risk of breast cancer among Japanese women: a nested case-control study.
Breast Cancer Res Treat
; 124(3): 827-34, 2010 Dec.
Article
em En
| MEDLINE
| ID: mdl-20440552
ABSTRACT
Although many in vitro and animal studies have suggested a protective effect of green tea against breast cancer, findings from epidemiological studies have been inconsistent. No study has used prediagnostic biomarkers of tea polyphenols, which might play a protective role. A total of 24,226 women aged 40 to 69 years in the Japan Public Health Center-based Prospective Study who responded to the baseline questionnaire and provided blood in 1990-1995 were followed to December 2002. During a mean 10.6 years of follow-up, 144 newly diagnosed breast cancers were identified. Two matched controls for each case were selected from the cohort. Plasma levels of (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epigallocatechin-3-gallate (EGCG), and (-)-epicatechin-3-gallate (ECG) were measured, and the odds ratio (OR) of breast cancer according to plasma level was estimated using a conditional logistic regression model. We found no statistically significant association between plasma tea polyphenol levels and breast cancer risk. Adjusted ORs for the highest versus lowest group were 0.90 (95% CI 0.42-1.96; P for trend = 0.98) for EGC, 0.95 (95% CI 0.43-2.08; P for trend = 0.86) for EC, 1.21 (95% CI 0.52-2.80; P for trend = 0.53) for EGCG, and 1.75 (95% CI 0.81-3.78; P for trend = 0.15) for ECG. Stratified analyses according to baseline menopausal status showed no remarkable difference between two strata. This nested case-control study found no overall association between plasma tea polyphenols and the risk of breast cancer in Japan.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenóis
/
Chá
/
Flavonoides
/
Neoplasias da Mama
Tipo de estudo:
Etiology_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
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Aged
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Female
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Humans
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Middle aged
País/Região como assunto:
Asia
Idioma:
En
Revista:
Breast Cancer Res Treat
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Japão