Effects of an equol-containing supplement on advanced glycation end products, visceral fat and climacteric symptoms in postmenopausal women: A randomized controlled trial.

INTRODUCTION: Equol, an isoflavone derivative whose chemical structure is similar to estrogen, is considered a potentially effective agent for relieving climacteric symptoms, for the prevention of lifestyle-related diseases, and for aging care in postmenopausal women. We investigated the effect of an equol-containing supplement on metabolism and aging and climacteric symptoms with respect to internally produced equol in postmenopausal women. METHODS: A single-center, randomized controlled trial (registration number: UMIN000030975) on 57 postmenopausal Japanese women (mean age: 56±5.37 years) was conducted. Twenty-seven women received the equol supplement, while the remaining received control. Metabolic and aging-related biomarkers were compared before and after the 3-month intervention. Climacteric symptoms were assessed every month using a validated self-administered questionnaire in Japanese postmenopausal women. RESULTS: Three months post-intervention, the treatment group showed significant improvement in climacteric symptoms compared to the control group (81% vs. 53%, respectively, p = 0.045). We did not observe any beneficial effect on metabolic and aging-related biomarkers in the intervention group. However, in certain populations, significant improvement in skin autofluorescence, which is a measurement of AGE skin products, and visceral fat area was observed, especially among equol producers. CONCLUSION: Women receiving equol supplementation showed improved climacteric symptoms. This study offered a new hypothesis that there may be a synergy between supplemented equol and endogenously produced equol to improve skin aging and visceral fat in certain populations.

Inter-relationship between diet, lifestyle habits, gut microflora, and the equol-producer phenotype: baseline findings from a placebo-controlled intervention trial.

OBJECTIVE: Equol is an active metabolite of isoflavones produced by gut microbiota. It is beneficial to health; however, equol-producing ability varies greatly among individuals. These variations depend on the host's gut microbiota and lifestyle habits including diet. We investigated the relationship between the gut microbiota, lifestyle habits including diet, and equol-producing ability in postmenopausal Japanese women. METHODS: We studied 58 postmenopausal Japanese women aged 48 to 69 years who visited the Sendai Medical Center in January, 2018. Self-administered questionnaires assessed their recent and remote food intake histories and lifestyle habits. Fecal microbiome analysis was performed using a next-generation sequencer. Urinary equol was measured using an immunochromatographic strip test. Women with urinary equol concentration >1.0 µM were defined as equol producers. RESULTS: Equol-producing bacteria were identified in 97% (56) of women; however, only 13 (22%) were equol producers. Equol producers showed significantly higher microflora diversity (P = 0.002), and significantly different recent and remote food intake patterns compared with equol nonproducers. Higher consumption of foods such as meat, fish, soy, vegetables, and Japanese snacks positively affected microbial diversity and equol production, whereas a high intake of Ramen and smoking showed negative effects. CONCLUSION: Equol production might not depend on the quantity, but on the quality of equol-producing bacteria. High microbial diversity might enhance equol production. Increasing microbial diversity through healthy lifestyle habits and habitual consumption of a wide variety of foods might be useful to maintain a healthy gut environment for equol production.

Effects of Equol Supplement on Bone and Cardiovascular Parameters in Middle-Aged Japanese Women: A Prospective Observational Study.

OBJECTIVE: To examine changes in the bone and cardiovascular parameters and tolerability in middle-aged Japanese women taking equol supplement for a year. DESIGN: This was a prospective observational study. SUBJECTS AND SETTING: Participants were 74 women receiving outpatient care at Hamasite Medical Clinic, Minato-ku, Tokyo, from 2013 to 2015. INTERVENTIONS: Participants received per oral equol-containing supplement, 10 mg/day. OUTCOME MEASURES: The primary outcome measures were percent changes in bone and cardiovascular parameters after 1 year supplementation with equol. The secondary measures included factors affecting the parameter changes and adverse effects associated with equol use for a year. RESULTS: Reduction in arterial stiffness was observed after 12 months of equol supplement (1402.3 cm/s vs.1367.3 cm/s, p < 0.001). Significant reductions in respective parameters were observed in women with moderate and high risk for arteriosclerosis (median [95% confidence interval]: -3.2% [-5.79 to -0.74]; -12.65% [-18.52 to -4.28]; respectively); hypertriglyceridemia -45.53% [-70.24 to -5.58]; bone resorption risk (-15.15% [-23.71 to 1.56]; and bone fracture risk -26.68% [-76.43 to -5.99]. All 15 women with high baseline parathyroid hormone levels had achieved a median of 50% [-54.11 to -31.69] reduction from their baseline values. These associations were further confirmed in the results of multiple linear regression analysis. There were no reported adverse events or abnormal findings in the blood chemistry, Pap smear, mammography, and transvaginal ultrasound during periodic follow-ups. CONCLUSION: One year equol supplement was tolerable and induced improvement of certain bone and cardiovascular parameters, especially in higher risk groups. Further controlled studies are needed to explore long-term equol use for wellbeing of middle-aged women.