Research Abstract |
The isoflavones are structurally similar to estradiol Hence, the estrogenicity of isoflavones may have beneficial effects on bone and skin health. The Japanese consume a diet that is very rich in the isoflavones, genistein and daidzein, which are found in soybeans and soy products. Soy and soy products are very rich in isoflavones, genistein and daidzein. The present study examined the relationships of soy intake estimated by a validated food frequency questionnaire, or serum isoflavones and isoflavone metabolites (genistein, daidzein, and equol) with several parameters of bone and skin health, such as bone mineral density (BMD, a bone formation marker, serum bone specific alkaline phosphatase activity, water and lipid contents, elasticity, and wrinkle of skin. In postmenopausal women, the ratio of estradiol to sex hormone-binding protein was statistically significantly correlated with BMD after controlling for covariates. However, isoflavone intake and serum isoflavones were not significantly correlated with BMD. In premenopausal women, isoflavone intake was not significantly correlated with BMD. We also measured serum insulinlike growth factor (IGF-1) which was implicated in the bone health to assess its relationship to dietary isoflavone. There was no significant correlation between soy isoflavone intake and serum IGF-1 levels. Skin health parameters, water, lipids, elasticity, index for wrinkle was measured among pre-and postmenopausal women. Preliminary analysis showed that these parameters were significantly correlated with age.
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