Hsu CC, et al. The assessment of efficacy of Diascorea alata for menopausal symptom treatment in Taiwanese women. Climacteric.. 2011;14:132-139.
A double-blind placebo-controlled trial of D. alata to treat menopausal symptoms was conducted. A total of 50 menopausal women were randomized to either D. alata extract, two sachets daily (12 mg/sachet) or placebo for 12 months. Primary outcome measure was change in the Greene Climacteric Scale with changes in plasma hormone profiles as secondary outcomes. A one-way ANCOVA test was performed to determine significance. At 6- and 12-month assessments, women assigned to the intervention showed general improvements for most clinical symptoms, with significant reductions in total Greene scores at treatment end (P < .01), and particularly for anxiety. Improvements were also noted for feeling tense or nervous (P = .007), insomnia (P = .004), excitability (P= .047), and musculoskeletal pain (P= .019). Positive effects on blood hormone profiles were also noted. Compared with placebo, standardized extracts of D. alata appeared to be safe for daily administration over a period of 12 months, with particular improvement in psychological parameters for menopausal women.
Wu WH, et al. Estrogenic effect of yam ingestion in healthy postmenopausal women. J Am Coll Nutr. 2005;24:235-243.
This small study investigated the effects of yam ingestion on lipids, antioxidant status, and sex hormones in healthy postmenopausal women. A total of 24 women replaced their staple diet of rice with yam (D. alata) 390 g for 2 of 3 daily meals over 1 month. Fasting blood and first morning urine samples were collected for 22 participants who completed the pre-/post-yam intervention. A similar study that evaluated 19 postmenopausal women who ate sweet potato 240 g for 41 days was use as a reference control. The yam dietary intervention resulted in significant increases of serum estrone levels and sex hormone binding globulin, with near-significant estradiol increases. There were no significant changes in serum DHEA-sulfate, androstenedione, testosterone, follicular stimulating hormone, and luteinizing hormone, but free androgen index and levels of urinary estrogen metabolites, urinary isoprostane, and plasma cholesterol decreased. LDL oxidation was also prolonged. In contrast, reference study control subjects who ate sweet potato had no changes in hormone parameters post-intervention. Investigators concluded that a 30-day, two-thirds replacement of staple food with yam improved sex hormone, lipid, and antioxidant status in postmenopausal women.