Flavonoid Intake and Plasma Sex Steroid Hormones, Prolactin, and Sex Hormone-Binding Globulin in Premenopausal Women.
BACKGROUND
Flavonoids potentially exert anti-cancer effects, as suggested by their chemical structures and supported by animal studies. In observational studies, however, the association between flavonoids and breast cancer, and potential underlying mechanisms, remain unclear.


OBJECTIVE
To examine the relationship between flavonoid intake and sex hormone levels using timed blood samples in follicular and luteal phases in the Nurses' Health Study II among premenopausal women.


METHODS
Plasma concentrations of estrogens, androgens, progesterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), prolactin, and sex hormone-binding globulin (SHBG) were measured in samples collected between 1996 and 1999. Average flavonoid were calculated from semiquantitative food frequency questionnaires collected in 1995 and 1999. We used generalized linear models to calculate geometric mean hormone concentrations across categories of the intake of flavonoids and the subclasses.


RESULTS
Total flavonoid intake generally was not associated with the hormones of interest. The only significant association was with DHEAS (p-trend = 0.02), which was 11.1% (95% confidence interval (CI): -18.6%, -3.0%) lower comparing the highest vs. lowest quartile of flavonoid intake. In subclass analyses, the highest (vs. lowest) quartile of flavan-3-ol intake was associated with significantly lower DHEAS concentrations (-11.3% with 95% CI: -18.3%, -3.7%, p-trend = 0.01), and anthocyanin intake was associated with a significant inverse trend for DHEA (-18.0% with 95% CI: -27.9%, -6.7%, p-trend = 0.003).


CONCLUSION
Flavonoid intake in this population had limited impact on most plasma sex hormones in premenopausal women. Anthocyanins and flavan-3-ols were associated with lower levels of DHEA and DHEAS.
['Wu|You|Y|0000-0001-9672-6129', 'Hankinson|Susan E|SE|', 'Smith-Warner|Stephanie A|SA|', 'Wang|Molin|M|', 'Eliassen|A Heather|AH|']
D000328:Adult D000728:Androgens D000872:Anthocyanins D003687:Dehydroepiandrosterone D019314:Dehydroepiandrosterone Sulfate D004034:Diet Surveys D004435:Eating D004967:Estrogens D005260:Female D005419:Flavonoids D012739:Gonadal Steroid Hormones D006306:Health Surveys D006801:Humans D016014:Linear Models D008875:Middle Aged D017697:Premenopause D011388:Prolactin D012738:Sex Hormone-Binding Globulin
flavonoid premenopausal women sex hormones biomarker circulating hormones