Dietary isoflavones affect sex hormone-binding globulin levels in postmenopausal women.
The studies presented in this report were designed to further investigate the causal association between phytoestrogen action and increase in sex hormone-binding globulin (SHBG) levels. Phytoestrogens include isoflavones that bind to estrogen receptors and therefore exert estrogenic action. This study included 20 postmenopausal women that ingested 30 g soy milk daily for 10 weeks. Plasma concentrations of isoflavones and SHBG were measured. Total isoflavones significantly increased from 0.014 +/- 0.01 micromol/L (baseline) to 0.53 +/- 0.19 ,micromol/L, and paired responses showed that some subjects clearly increased their SHBG levels. The percent change in SHBG showed a positive correlation with phytoestrogen concentration; all women who had circulating phytoestrogen levels above 0.6 micromol/L increased by at least 30% their SHBG values. Results suggest that phytoestrogens may significantly increase SHBG in subjects whose SHBG concentrations are in the low end of the concentration range.
Pino
A M
AM
Instituto De Nutrición y Tecnología de Los Alimentos, Universidad de Chile, Santiago.
Valladares
L E
LE
Palma
M A
MA
Mancilla
A M
AM
Yáñez
M
M
Albala
C
C
D000368:Aged; D001628:Beverages; D015992:Body Mass Index; D004958:Estradiol / Q000097:blood; D004968:Estrogens, Non-Steroidal / Q000097:blood; D004970:Estrone / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D008875:Middle Aged; D048789:Phytoestrogens; D028321:Plant Preparations; D017698:Postmenopause / Q000097:blood*; D012044:Regression Analysis; D012738:Sex Hormone-Binding Globulin / Q000032:analysis / Q000378:metabolism*; D013025:Glycine max
D004968:Estrogens, Non-Steroidal; D007529:Isoflavones; D048789:Phytoestrogens; D028321:Plant Preparations; D012738:Sex Hormone-Binding Globulin; D004970:Estrone; D004958:Estradiol; D005640:Follicle Stimulating Hormone