Soy germ isoflavones improve menopausal symptoms but have no effect on blood lipids in early postmenopausal Chinese women: a randomized placebo-controlled trial

Objective: Estrogen therapy is, to date, the most effective treatment of menopausal syndrome and also has a favorable effect on lipid profiles. Because of its potential adverse effects, however, a more acceptable alternative therapy needs to be identified. This study examines the effect of soy germ isoflavones on menopausal symptoms and serum lipids. Methods: Ninety early postmenopausal Chinese women, aged 45 to 60 years, were randomly assigned to three treatment groups (30 each) receiving daily doses of 0 (placebo), 84, and 126 mg of soy germ isoflavones. Hot flush frequency, Kupperman scores, serum 17 beta-estradiol, follicle-stimulating hormone, luteinizing hormone, and serum lipids, including triglyceride, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I, and apolipoprotein B100, were assessed at baseline and at 12 and 24 weeks after treatment. Results: Both the frequency of hot flushes and the Kupperman index score decreased in all three treatment groups during the intervention period, but the percentage decreases in both were significantly greater in the two isoflavone groups (44.3 +/- 19.1 and 57.8 +/- 37.4 [84 mg isoflavones]; 48.5 +/- 27.2 and 56.7 +/- 26.7 [126 mg isoflavones]) than in the placebo group (27.8 +/- 15.5 and 34.6 +/- 46.2; p < 0.01). There was no significant difference in the changes in estradiol, follicle-stimulating hormone, and luteinizing hormone among the three treatment groups during the study, and no significant differences were observed in the lipid components. Conclusions: A daily supplement of 84 or 126 mg soy germ isoflavones may improve menopausal symptoms, although neither dose was found to affect lipid profiles in early postmenopausal Chinese women after 24 weeks of treatment. The favorable effects are unlikely to be associated with female hormones.