title: Soy isoflavones in the prevention of menopausal bone loss and menopausal symptoms: a randomized, double-blind trial.
abstract: BACKGROUND
  Concerns regarding the risk of estrogen replacement have resulted in a significant increase in the use of soy products by menopausal women who, despite the lack of evidence of the efficacy of such products, seek alternatives to menopausal hormone therapy. Our goal was to determine the efficacy of soy isoflavone tablets in preventing bone loss and menopausal symptoms.
  
  
  METHODS
  The study design was a single-center, randomized, placebo-controlled, double-blind clinical trial conducted from July 1, 2004, through March 31, 2009. Women aged 45 to 60 years within 5 years of menopause and with a bone mineral density T score of -2.0 or higher in the lumbar spine or total hip were randomly assigned, in equal proportions, to receive daily soy isoflavone tablets, 200 mg, or placebo. The primary outcome was changes in bone mineral density in the lumbar spine, total hip, and femoral neck at the 2-year follow-up. Secondary outcomes included changes in menopausal symptoms, vaginal cytologic characteristics, N -telopeptide of type I bone collagen, lipids, and thyroid function.
  
  
  RESULTS
  After 2 years, no significant differences were found between the participants receiving soy tablets (n = 122) and those receiving placebo (n = 126) regarding changes in bone mineral density in the spine (-2.0% and -2.3%, respectively), the total hip (-1.2% and -1.4%, respectively), or the femoral neck (-2.2% and -2.1%, respectively). A significantly larger proportion of participants in the soy group experienced hot flashes and constipation compared with the control group. No significant differences were found between groups in other outcomes.
  
  
  CONCLUSIONS
  In this population, the daily administration of tablets containing 200 mg of soy isoflavones for 2 years did not prevent bone loss or menopausal symptoms.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00076050.
authors.affiliation: Geriatric Research, Education, and Clinical Center, Miami Veterans Affairs Healthcare System, USA. slevis@med.miami.edu
authors.forename: Silvina
authors.initials: S
authors.lastname: Levis
authors.forename: Nancy
authors.initials: N
authors.lastname: Strickman-Stein
authors.forename: Parvin
authors.initials: P
authors.lastname: Ganjei-Azar
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Doerge
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Krischer
mesh_terms: D019587:Dietary Supplements; D004311:Double-Blind Method; D015914:Estrogen Replacement Therapy / Q000379:methods*; D005260:Female; D019833:Genistein / Q000009:adverse effects / Q000627:therapeutic use; D019584:Hot Flashes / Q000517:prevention & control*; D006801:Humans; D007529:Isoflavones / Q000009:adverse effects / Q000627:therapeutic use*; D016015:Logistic Models; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D048789:Phytoestrogens / Q000009:adverse effects / Q000627:therapeutic use*; D008517:Phytotherapy; D013025:Glycine max
chemical_list: D007529:Isoflavones; D048789:Phytoestrogens; C004742:daidzein; D019833:Genistein