A randomized, double-blind, placebo-controlled study to examine the effects of high-isoflavone soybeans “Yukipirika” in climacteric women

Abstract

Background: Soy isoflavones belong to a class of plant-based compounds known as phytoestrogens and effect menopausal symptoms and bone metabolism. We evaluated the effects of high-isoflavone soybeans (“Yukipirika”) in climacteric women.Methods: In this randomized, double-blind, placebo-controlled study, we randomly selected 64 female subjects (aged 46–60 years) to consume products made from high-isoflavone soybeans (active test), low-isoflavone soybeans (Placebo 2), or wheat (Placebo 1). The simplified menopausal index (SMI) test, visual analog scale (VAS) of skin and hair conditions, joints functions, and bowel movements, hematological analysis, and urinalysis were performed at weeks 0, 4, and 8 during the study period. Results: Intake of high-isoflavone soybeans did not change bone metabolism parameters. However, a subsection of the SMI score was improved in the active test food group compared to the Placebo 2 food group. Additionally, VAS of skin conditions, joints functions, and bowel movements improved in the active test group compared to the Placebo 1 or Placebo 2 groups. Conclusion: These results suggest that the ingestion of high-isoflavone soybeans can improve skin conditions, joints functions, and bowel movements, in addition to menopausal symptoms.Keywords: bone metabolism; clinical trial; isoflavone; soybeans; menopausal symptoms; Yukipirika