Can Soy Help Menopausal Hot Flashes and Night Sweats?A new women’s health, whole soy germ-based nutritional supplement containing Natural S-equol reduced the frequency of moderate to severe hot flashes and night sweats and reduced muscle and joint pain in the first study of its kind among postmenopausal U.S. women, according to peer-reviewed data 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 U.S. 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. 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,” 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.
S-equol [7-hydroxy-3-(4’-hydroxyphenyl)-chroman] is a compound resulting -- when certain bacteria are present in the digestive tract -- 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 percent of Asians and 20 to 30 percent 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 milligrams (mg) of Natural S-equol reduced the frequency of moderate to severe hot flashes as 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 percent or more reduction in their hot flash frequency, a primary endpoint of the study, than in the isoflavone group: respectively, 42.9 (P=0.056), 27.3, 25.0 and 16.0 percent. 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 (P=0.076), the 10 mg dose was similar (P=0.503) and the 40 mg dose was significantly more effective than the soy isoflavones in reducing hot flash frequency (P=0.021), 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.
Moreover, muscle and joint pain was reduced significantly in the 10 and 20 mg Natural S-equol groups compared to those in the isoflavone group (P< 0.05). 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,” explained Jenks.