Effect of whole soy and purified daidzein on androgenic hormones in chinese equol-producing post-menopausal women: a six-month randomised, double-blinded and Placebo-Controlled trial
What this study found
Purified daidzein produced modest but statistically significant reductions in serum testosterone and androstenedione versus placebo, while whole soy showed only a marginal reduction in free androgen index. At 6 months, daidzein vs placebo changed testosterone by -0.057 nmol/L (95% CI -0.185 to 0.070, p = .018) and androstenedione by -0.118 ng/mL (95% CI -0.240 to -0.004, p = .045); 6-month percent change in testosterone was -8.557% (95% CI -8.168 to 15.054%, p = .026). Prolactin, SHBG, and DHEA-S were not significantly changed between groups. Adverse events were uncommon, although two women…
- Study & population
- Randomized, double-blind, placebo-controlled three-arm trial in Hong Kong Chinese equol-producing postmenopausal women.
- Intervention
- Whole soy: 40 g soy flour taken orally once daily for 6 months, providing 12.8 g protein and 49.8 mg total isoflavones (23.2 mg daidzein and 19.4 mg genistein).
- Key limitation
- The effects were modest, and the clinical significance is uncertain.
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Open PDFOriginal abstract
Abstract A randomised, double-blind and placebo-controlled trial was performed to examine the effects of whole soy and isoflavone daidzein on serum androgenic hormones in Chinese equol-producing post-menopausal women. A total of 270 eligible women aged 45–70 years were randomised to either one of the three iso-caloric supplements: 40 g soy flour (whole soy group), 40 g low-fat milk powder +63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo group) daily for 6 months. Fasting venous samples were tested for serum androstenedione (AD), testosterone (T), prolactin, sex hormone binding globulin and dehydroepiandrosterone sulphate. Intention-to-treat analysis indicated that serum T (p = .022) and AD (p = .05) levels modestly but significantly decreased after 6-month daidzein treatment in comparison with placebo, with a mean difference of –0.057 nmol/L (95%CI: –0.185 to 0.070, p = .018) and –0.118 ng/mL (95%CI: –0.240–0.004, p = .045), respectively. This 6-month trial suggested that purified daidzein may exhibit less androgenic effect. Trial registration: The trial was registered in ClinicalTrials.gov with identifier of NCT01270737. (URL: http://clinicaltrials.gov/ct2/show/NCT01270737.)