Submitted to: International Soy Conference
Publication Type: Abstract Only
Publication Acceptance Date: 8/14/2008
Publication Date: 11/11/2008
Citation: Steinberg, F.M., Barns, S., Murry, M.J., Lewis, R.D., Fisher, J.G., Cramer, M.A., Amato, P., Young, R.L., Ellis, K.J., Shypailo, R.S., Smith, E.O., Fraley, J.K., Wong, W.W. 2008. Equol and its relation to osteoporosis prevention using soy [abstract]. 8th International Symposium on the Role of Soy, in Health and Chronic Disease Prevention, November 9-12, 2008, Tokyo, Japan. Interpretive Summary:
Technical Abstract: Soy isoflavones are believed to have anti-osteoporotic properties, but the relationship to equol production status is unclear. To evaluate effects of soy isoflavones and metabolites on bone loss, 403 early postmenopausal women (54.0+/-4.0 y) were enrolled in an intent-to-treat, multi-site, 2-year, randomized, double-blind trial. Treatment groups were 1/3 on placebo, 1/3 on 80 mg/d soy hypocotyl isoflavones, and 1/3 on 120 mg/d soy hypocotyl isoflavones, along with 1,000 mg/d of CaCO3 and daily multivitamin with 400 IU vitamin D. Bone mineral density (BMD) of the whole body (WB), hip and spine were measured at baseline and annually. Ten serum isoflavones and metabolites were analyzed by LC/MS with an equol producer defined as =20nmol/L equol. Markers of bone turnover and metabolic health profiles were also measured at annual intervals. Baseline characteristics were similar in the three groups. Although a small but statistically significant protective effect on the decrease in WB BMD was observed with treatment of 120 mg/d soy isoflavones vs. placebo after 1 y (p=0.027) and 2 y (p=0.048), WB BMD was not correlated with serum equol at 1 y or 2 y. Analysis of variance for equol producer status and WB BMD also was not statistically significant. Serum equol values ranged from 1.07– 6080 nmol/L. In equol producers (30% of subjects at y1) the mean equol concentration was 1009 +/- 1241 nmol/L, median 477 nmol/L. Preliminary results do not support an association of equol production status with maintenance of WB BMD.