The study – published in the Journal of Women's Health – reports that daily doses of a soy germ-based nutritional supplement containing S-equol improved menopausal symptoms in postmenopausal Japanese women, including significantly reducing hot flush frequency, when compared to compared to a placebo.
The 12 week trial, led by Shigeto Uchiyama of Otsuka Pharmaceutical Co, Japan, tested the effects of a 10-mg natural S-(−)equol supplement consumed daily on major menopausal symptoms – specifically, hot flushes and neck or shoulder muscle stiffness – finding the supplement had beneficial effects on both symptoms.
“This supplement offers a promising alternative for management of menopausal symptoms,” said Uchiyama, and colleagues.
Belinda Jenks, Ph.D, director of Scientific Affairs & Nutrition Education at Pharmavite LLC, USA, explained that data from the study, and other clinical studies, “shows that the supplement ... containing S-equol may serve as a promising alternative for reducing the frequency of hot flushes and perhaps other menopausal symptoms."
Otsuka Pharmaceutical Co. Ltd. supported the study. The data was first presented in an oral presentation at the North American Menopause Society annual meeting in October 2009.
In the double-blind, randomized study, Uchiyama and colleagues measured the daily frequency of women's hot flushes.
They reported that after 12 weeks, frequency had decreased by 58.7% for the 66 women receiving the soy supplement – significantly more than the 34.5% reduction witnessed by the 60 women receiving a placebo.
The researchers noted that of the 34 women who enrolled with at least three hot flushes daily, those receiving the soy supplement experienced a 62.8% reduction in frequency.
Moreover, the women taking the S-equol soy had significant decreases in the severity of their hot flushes, as measured by the Climacteric Symptom Evaluation Form Checklist, said Uchiyama and co-workers.
The team also found a significant decrease in neck and shoulder stiffness for women receiving the supplementation compared to those in the placebo group.
S-equol is the product of fermentation of soy germ by the bacterial strain Lactococcus 20-92 using a patented and proprietary process by the Otsuka Pharmaceutical Co., Ltd. The process results in the conversion of the daidzein to S-equol.
Preliminary evidence from other, observational studies suggests that Japanese women who produce S-equol naturally may have fewer menopausal symptoms.
"It is believed that S-equol, produced from the isoflavone daidzein during the fermentation of soy germ, interacts with specific estrogen receptors to promote the improvement in menopausal symptoms,” explained Jenks.
Development and ongoing research of supplements containing S-equol is being conducted by the Saga Nutraceuticals Research Institute, part of Otsuka Pharmaceutical Co.
Source: Journal of Women's Health
Published online ahead of print, doi: 10.1089/jwh.2011.2753
“A Natural S-(−)Equol Supplement Alleviates Hot Flushes and Other Menopausal Symptoms in Equol Nonproducing Postmenopausal Japanese Women”
Authors: T. Aso, S. Uchiyama, Y. Matsumura, M. Taguchi, M. Nozaki, K. Takamatsu, et al