title: Relationship between dietary phytoestrogens and development of urinary incontinence in midlife women.
abstract: OBJECTIVE
  Because exogenous estrogen treatment has been associated with a higher risk of urinary incontinence, our objective was to evaluate the longitudinal relationships of dietary phytoestrogen intakes (isoflavones, coumestans, and lignans) and the development of incontinence in midlife women transitioning through menopause.
  
  
  METHODS
  The Study of Women's Health Across the Nation (SWAN) Phytoestrogen Study was developed within SWAN, a community-based, multisite, multiracial/ethnic, prospective cohort study. SWAN interviewers administered a food consumption assessment at baseline and on follow-up visits 5 and 9. The SWAN Phytoestrogen Study created a phytonutrient database that allowed estimation of the usual daily intakes of four isoflavones, four lignans, and coumestrol. On an annual self-administered questionnaire, participants reported on the frequency and type of incontinence. We used discrete proportional hazards models to evaluate whether the estimated daily intake of each phytoestrogen class on the visit previous to the first report of incontinence was associated with the development of monthly or more incontinence versus remaining continent.
  
  
  RESULTS
  We found no association or patterns of association between developing any, stress, or urge incontinence and the reported daily dietary intake of isoflavones, coumestrol, and lignans on the visit previous to the onset of incontinence.
  
  
  CONCLUSIONS
  The results of this longitudinal study provide important information to better understand estrogenlike substances in the continence mechanism of midlife women. Our study shows that neither high nor low dietary intakes of isoflavones, coumestrol, and lignans prevent stress or urge incontinence. Future studies should evaluate whether serum levels of phytoestrogens or their metabolites impact incontinence symptoms.
authors.affiliation: Department of Obstetrics and Gynecology, University of California Davis School of Medicine, Sacramento, CA 95817, USA. lewaetjen@ucdavis.edu
authors.forename: L Elaine
authors.initials: LE
authors.lastname: Waetjen
authors.forename: Katherine
authors.initials: K
authors.lastname: Leung
authors.forename: Sybil L
authors.initials: SL
authors.lastname: Crawford
authors.forename: Mei-Hua
authors.initials: MH
authors.lastname: Huang
authors.forename: Ellen B
authors.initials: EB
authors.lastname: Gold
authors.forename: Gail A
authors.initials: GA
authors.lastname: Greendale
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003375:Coumestrol / Q000008:administration & dosage; D004032:Diet; D005006:Ethnicity; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage; D017705:Lignans / Q000008:administration & dosage; D008137:Longitudinal Studies; D008593:Menopause; D008875:Middle Aged; D048789:Phytoestrogens / Q000008:administration & dosage*; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014549:Urinary Incontinence / Q000453:epidemiology* / Q000208:ethnology; D016387:Women's Health
chemical_list: D007529:Isoflavones; D017705:Lignans; D048789:Phytoestrogens; D003375:Coumestrol