Soy-based supplement reduces menopausal hot flashes, muscle and joint pain

Washington, April 25(ANI): Daily dose of a newly developed fermented soy germ-based nutritional supplement containing 10 mg of S-equol is as effective as a standard dose of soy isoflavones at reducing hot flash frequency significantly and is even more effective for relieving muscle and joint pain, researchers have claimed.

Development and ongoing research of the supplement is conducted by the Saga Nutraceuticals Research Institute of Otsuka Pharmaceutical Co., Ltd.

Pharmavite LLC, the makers of Nature Made vitamins and minerals, is a subsidiary of Otsuka, which supported the study.

"This study provides evidence that daily doses of the supplement S-equol, a metabolite of the soy isoflavone daidzein, reduced hot flash frequency and relieved muscle and joint pain in U.S. postmenopausal women. These findings confirm earlier studies in Japanese women documenting S-equol's ability to relieve menopausal symptoms," said Belinda H. Jenks, Ph.D., co-author of the study and director of Scientific Affairs and Nutrition Education at Pharmavite LLC.

Daily doses of the supplement containing 10, 20 or 40 mg of S-equol each reduced the frequency of moderate to severe hot flashes similarly to a 50 mg dose of a soy isoflavone supplement in a double-blinded randomised study involving 102 US postmenopausal women aged 45 to 65 who experienced more than 35 hot flashes weekly when they enrolled.

The investigators used a standardized soy isoflavone supplement for comparison in the study because of the scientific consensus that extracts or concentrated soy isoflavones support relief of hot flashes in menopausal women, based on placebo-controlled studies.

The investigators observed, after eight weeks of treatment, significant reductions occurred from the study start in the women's average daily hot flashes, the study's primary endpoint.

These reductions were comparable for all three S-equol treatment groups, 10, 20 or 40 mg, which ranged from decreases of 3.09 to 3.66 hot flashes daily, to that of the soy isoflavone group, which averaged decreases of 2.92. The average number of daily hot flashes in all of the participants at the study start was 10.0 ± 4.03.

Muscle and joint pain improved significantly for both the 10 and 20 mg doses of S-equol compared with the soy isoflavones (p=0.003 and p=0.005, respectively), based on scores from the Greene Climacteric Scale (GCS), which measures 21 symptoms using 0 to 3 scale, where 0 was 'not at all,' 1 was 'a little,' 2 was 'quite a bit' and 3 was 'extremely,' to produce scores.

"These U.S. data expand on the previous studies in Japanese women and further document that a minimum daily 10 mg dose of S-equol would likely help women by both reducing the frequency of their hot flashes as well as decreasing their muscle and joint pain associated with menopause," said Jenks.

Further, for women who had more than eight hot flashes daily at the study start, both 20 and 40 mg S-equol were significantly better than the soy isoflavones in reducing hot flash frequency (p=0.045 and p=0.001, respectively), while the 10 mg S-equol dose had a strong positive trend (p=0.063), according to a sub-group analysis.

This finding suggests that the S-equol supplement might be more useful for the women who have a higher frequency of hot flashes, Jenks said.

Also, more women in the 10, 20 and 40 mg S-equol groups achieved a reduction of 50 percent or more in their hot flash frequency by the study end than in the soy isoflavone group: respectively, 25.0, 27.3, 42.9 (P=0.056) and 16.0 percent.

No significant differences occurred between any of the S-equol groups and the soy isoflavone group for two secondary endpoints: the hot flash severity and the psychological (anxiety, depression), somatic (physical), vasomotor GCS subscales.

The study has been published in the June Journal of Women's Health, available now as a Fast Track article online ahead of print. (ANI)