title: Associations between urine excretion of isoflavonoids and cognition in postmenopausal women in the Women's Isoflavone Soy Health clinical trial.
abstract: OBJECTIVE
  To determine effect of change in urine excretion of isoflavonoids on cognitive change.
  
  
  METHODS
  Post hoc analysis of isoflavonoid exposure (mean 2.7 years) during the randomized, placebo-controlled, double-blind Women's Isoflavone Soy Health trial.
  
  
  METHODS
  General community.
  
  
  METHODS
  Healthy postmenopausal women (N = 350).
  
  
  METHODS
  Twenty-five grams of isoflavone-rich soy protein (91 mg of aglycone weight isoflavones: 52 mg genistein, 36 mg daidzein, 3 mg glycitein) or milk protein-matched placebo provided daily.
  
  
  METHODS
  Overnight urine excretion, fasting plasma levels of isoflavonoids, and cognitive function measured at baseline and endpoint.
  
  
  RESULTS
  Three hundred women (age: mean 61, range 45-92) completed both cognitive assessments and did not use hormone replacement therapy during the trial. Mean on-trial change from baseline in urine excretion of isoflavonoids was not significantly associated with change in a composite score of global cognition (P = .39). Secondary analyses indicated that change in urine excretion of isoflavonoids was inversely associated with change in a factor score representing general intelligence (P = .02) but not with factor scores representing verbal or visual episodic memory. Mean differences in this general intelligence factor score between women in the lowest and highest quartiles of isoflavonoid change were equivalent to an approximate 4.4-year age-associated decline. Analyses based on plasma isoflavonoid levels yielded similar but attenuated results.
  
  
  CONCLUSIONS
  In healthy postmenopausal women, long-term changes in isoflavonoids are not associated with global cognition, supporting clinical trial results, although greater isoflavonoid exposure from dietary supplements is associated with decrements in general intelligence but not memory; this finding requires confirmation in future studies.
authors.affiliation: Atherosclerosis Research Unit, University of Southern California, Los Angeles, California; Department of Preventive Medicine, University of Southern California, Los Angeles, California.
authors.forename: Jan A
authors.initials: JA
authors.lastname: St John
authors.forename: Victor W
authors.initials: VW
authors.lastname: Henderson
authors.forename: Howard N
authors.initials: HN
authors.lastname: Hodis
authors.forename: Naoko
authors.initials: N
authors.lastname: Kono
authors.forename: Carol A
authors.initials: CA
authors.lastname: McCleary
authors.forename: Adrian A
authors.initials: AA
authors.lastname: Franke
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Mack
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000517:prevention & control; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000178:diet therapy / Q000503:physiopathology / Q000652:urine*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000097:blood / Q000652:urine*; D008568:Memory / Q000187:drug effects; D008875:Middle Aged; D014674:Plant Proteins, Dietary / Q000008:administration & dosage / Q000493:pharmacokinetics; D017698:Postmenopause; D011379:Prognosis; D012016:Reference Values; D030262:Soybean Proteins / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013997:Time Factors; D016482:Urinalysis; D016387:Women's Health
chemical_list: D007529:Isoflavones; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins
keywords: cognition; isoflavones; menopause; soy; women's health