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

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.)

Keywords:

• Whole soy
• Daidzein
• post-menopausal women
• androgenic hormones
• equol producers

Acknowledgements

ZML drafted the manuscript and explained the results. GYL and DZ conducted statistical analysis and formulated the result tables. Serum biochemical analysis was conducted by KingMed Dignostics, Guangzhou, China.

Disclosure statement

All authors declare no conflict of interests. Neither One Hundred Person Project of Sun Yat-sen University and Hong Kong Research Grant Committee, as well as soy and dairy company had any role in the design and conduct of the study; the collection, analysis and interpretation of the data; or the preparation, review and approval of the manuscript.

Additional information

Funding

The trial was funded by the foundation of One Hundred Persons Project of Sun Yat-sen University and Hong Kong Research Grant Committee-General Research Fund [RGC-GRF465810].