Soy-based Supplement Improves Menopause Symptoms

Researchers show that natural S-equol can help with three common symptoms of menopause.

Results from a first study among postmenopausal US women, reveals that a new health nutritional supplement containing Natural S-equol reduces the frequency of moderate to severe hot flashes and reduces muscle and joint pain.

The peer-reviewed data was presented as a poster presentation at the North American Menopause Society (NAMS) Annual Meeting. Also, the first study to report Natural S-equol contributions to bone health and a study of Natural S-equol safety were presented at NAMS.

“These data from US women expand our knowledge about and corroborate previous research in Japanese women about the benefit of a supplement containing the soy-based compound Natural S-equol to manage menopausal symptoms, including reducing the frequency of hot flashes and muscle discomfort,” said Belinda H. Jenks, Ph.D., coauthor of the US women's and safety studies and director of Scientific Affairs & Nutrition Education at Pharmavite LLC, in a press release. “This and the other Natural S-equol studies are part of the rigorous clinical collaborative program of Pharmavite LLC and Otsuka Pharmaceutical Co., Ltd. to develop a supplement containing Natural S-equol.”

S-equol [7-hydroxy-3-(4'-hydroxyphenyl)-chroman] is a compound resulting from the natural metabolism, or conversion, of daidzein, an isoflavone found in whole soybeans. Not everyone can produce S-equol after soy consumption, as the production depends on the types of bacteria present in the large intestine and may be influenced by the amount of soy consumed. About 50% of Asians and 20 to 30% of North Americans and Europeans, who in general consume less soy than Asians, have the ability to produce S-equol. Research indicates that Japanese women have milder menopausal symptoms in those who are S-equol producers compared to nonproducers.

S-equol selectively binds to the receptors for the naturally occurring female sex hormone estrogen, with a strong affinity to the estrogen receptor beta. On binding to these receptors, S-equol mimics some, but not all, activities of natural estrogen. Because of these actions at the receptor, it has been proposed that S-equol may alleviate some of the symptoms caused by diminished estrogen production during menopause.

Natural S-equol Supplement Reduces Menopausal Hot Flashes in U.S. Women

In the double-blinded study of 102 US postmenopausal women, eight weeks of daily SE5-OH supplement doses containing 10, 20 or 40 mg of Natural S-equol reduced the frequency of moderate to severe hot flashes and so did 50 mg doses of a soy isoflavone supplement. Because isoflavones are known to have mild effects on the reduction of hot flashes in menopausal women, the investigators used an isoflavone supplement as a comparator in the study.

More women in the 10, 20 and 40 mg Natural S-equol groups achieved a 50% or more reduction in their hot flash frequency, a primary endpoint of the study, than in the isoflavone group. To enroll in the study, all of the women had to experience more than 35 hot flashes per week.

The 20 mg Natural S-equol dose neared statistical superiority, the 10 mg dose was similar, and the 40 mg dose was significantly more effective than the soy isoflavones in reducing hot flash frequency, according to a Mixed-Effect Model Repeated Measure analysis incorporating the eight weekly reports of women's hot flash frequency, a secondary endpoint of the study.

Muscle and joint pain was reduced significantly as well in the 10 and 20 mg Natural S-equol groups compared to those in the isoflavone group. Investigators used the validated Greene Climacteric Scale that measures 20 symptoms to produce three symptom measures: psychological, somatic (physical) and vasomotor.

“Together these data document that a minimum daily dose of 10 mg Natural S-equol would provide the benefit of both reducing the frequency of moderate to severe hot flashes as well as decreasing muscle and joint pain associated with menopause,” Jenks said.

The trial also noted treatment-emergent adverse effects in participants of all the treatment groups. Such effects occurred in more than 5% of each group and included abdominal distention, constipation, and endometrial hypertrophyS. No trends or clinically meaningful changes were identified in laboratory blood or urine tests, electrocardiographs, physical examinations or vital signs among the participants.

Natural S-equol Inhibits Bone Break Down, Prevents Bone Mineral Density Loss

This study is the first to document evidence that daily doses of SE5-OH supplements containing 10 mg of Natural S-equol given for 12 months significantly inhibited bone break down, or resorption, in postmenopausal women. Treatment with the 10 mg Natural S-equol dose significantly prevented a decrease in whole body bone mineral density (BMD), compared to placebo.

“These findings raise the possibility that 10 mg daily of Natural S-equol supplementation may contribute to bone health without adverse effects in postmenopausal women who can not make S-equol themselves after eating soy. Further research is needed to determine the effects of S-equol on bone metabolism and safety,” Jenks said.

In this one-year, double-blind, placebo-controlled study, investigators randomized 93 Japanese women to receive a placebo or one of three daily doses of SE5-OH containing Natural S-equol: 2, 6 or 10 mg. Women studied were equol nonproducers, and averaged 53.8 years old and 2.7 years since menopause. After one year, women receiving the 10 mg dose of Natural S-equol had significantly decreased, by 23.9%, the amount of urinary deoxypyridinoline (DPD) for 24 hours, a validated marker for bone resorption, compared to a reduction of just 2.9% in the placebo group (P=0.020).

In addition, the whole body BMD in the 10 mg group declined by 1.1%, significantly less than the 1.9% decrease of the placebo group at 12 months.

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Do you currently have menopausal patients that are using a form of soy-based supplementation? Do the study findings affect how you view the potential role of soy supplementation during menopause?