Antiresorptive Effects of Phytoestrogen Supplements Compared with Estradiol or Risedronate in Postmenopausal Women Using Ca-41 Methodology

Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana 47907-2059, USA.
The Journal of Clinical Endocrinology and Metabolism (Impact Factor: 6.31). 08/2009; 94(10):3798-805. DOI: 10.1210/jc.2009-0332
Source: PubMed

ABSTRACT Reduction of ovarian estrogen secretion at menopause increases net bone resorption and leads to bone loss. Isoflavones have been reported to protect bone from estrogen deficiency, but their modest effects on bone resorption have been difficult to measure with traditional analytical methods.
In this randomized-order, crossover, blinded trial in 11 healthy postmenopausal women, we compared four commercial sources of isoflavones from soy cotyledon, soy germ, kudzu, and red clover and a positive control of oral 1 mg estradiol combined with 2.5 mg medroxyprogesterone or 5 mg/d oral risedronate (Actonel) for their antiresorptive effects on bone using novel (41)Ca methodology.
Risedronate and estrogen plus progesterone decreased net bone resorption measured by urinary (41)Ca by 22 and 24%, respectively (P < 0.0001). Despite serum isoflavone profiles indicating bioavailability of the phytoestrogens, only soy isoflavones from the cotyledon and germ significantly decreased net bone resorption by 9% (P = 0.0002) and 5% (P = 0.03), respectively. Calcium absorption and biochemical markers of bone turnover were not influenced by interventions.
Dietary supplements containing genistein-like isoflavones demonstrated a significant but modest ability to suppress net bone resorption in postmenopausal women at the doses supplied in this study over a 50-d intervention period.

Download full-text


Available from: Susan Reinwald, Aug 26, 2015
  • Source
    • "Regarding the importance of BMD as well as bone biomarkers in bone health assessment, there are several different types of studies that assessed bone remodeling after phytoestrogens intake and their results are conflicting. Some studies in postmenopausal women reported significant decrease in bone resorption markers (Crisafulli et al. 2004; Evans et al. 2007) in contrast to the others who reported nonsignificant changes in bone resorption markers (Albertazzi et al. 2005; Wangen et al. 2000) and bone formation markers (Albertazzi et al. 2005; Weaver et al. 2009). In addition, the BMD changes Effect size meta-analysis plot [random effects] "
    [Show abstract] [Hide abstract]
    ABSTRACT: Phytoestrogens as selective estrogen receptor modulators like compounds may consider as a therapeutic option in osteoporosis. In this regard, the effect of phytoestrogens on bone biomarkers was examined in several trials which their results are controversial. We aimed this meta-analysis to evaluate the net effect of phytoestrogens on bone markers. A thorough search was conducted from 2000 to 2010 in English articles. All randomized clinical trials were reviewed, and finally, 11 eligible randomized clinical trials were selected for meta-analysis. Totally 1,252 postmenopausal women were enrolled in the study by considering the changes of pyridinoline (Pyd), desoxypyridinoline (Dpyd), bone alkaline phosphatase, and osteocalcin concentrations in urine and serum after phytoestrogens consumption. The urine Pyd and Dpyd levels decreased significantly in phytoestrogens consumers. Effect size and effect size for weighted mean difference of urine Pyd levels showed -1.229171 (95% confidence interval (CI) = -1.927639 to -0.530703) and -9.780623 (95% CI = -14.240401 to -5.320845), respectively, a significant results in comparison to control group and significant results for Dpyd -0.520132 (95% CI = -0.871988 to -0.168275) and -0.818582 (95% CI = -1.247758 to -0.389407), respectively. Meta-analysis indicates that phytoestrogens intake can prevent bone resorption, but its benefits on bone formation are not significant. This favorable effect was observed in low doses and in at least 3 weeks of phytoestrogens intake.
    Age 09/2011; 33(3):421-31. DOI:10.1007/s11357-010-9180-6 · 3.45 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Plant derived products are consumed by a large percentage of the population to prevent, delay and ameliorate disease burden; however, relatively little is known about the efficacy, safety and underlying mechanisms of these traditional health products, especially when taken in concert with pharmaceutical agents. The flavonoids are a group of plant metabolites that are common in the diet and appear to provide some health benefits. While flavonoids are primarily derived from soy, many are found in fruits, nuts and more exotic sources, e.g., kudzu. Perhaps the strongest evidence for the benefits of flavonoids in diseases of aging relates to their effect on components of the metabolic syndrome. Flavonoids from soy, grape seed, kudzu and other sources all lower arterial pressure in hypertensive animal models and in a limited number of tests in humans. They also decrease the plasma concentration of lipids and buffer plasma glucose. The underlying mechanisms appear to include antioxidant actions, central nervous system effects, gut transport alterations, fatty acid sequestration and processing, PPAR activation and increases in insulin sensitivity. In animal models of disease, dietary flavonoids also demonstrate a protective effect against cognitive decline, cancer and metabolic disease. However, research also indicates that the flavonoids can be detrimental in some settings and, therefore, are not universally safe. Thus, as the population ages, it is important to determine the impact of these agents on prevention/attenuation of disease, including optimal exposure (intake, timing/duration) and potential contraindications.
    Maturitas 02/2010; 66(2):163-71. DOI:10.1016/j.maturitas.2010.01.010 · 2.86 Impact Factor
Show more