title: Endocrine and cognitive effects of short-time soybean consumption in women.
abstract: BACKGROUND
  Soy phytoestrogens are known to influence the hormonal status acting as partial estrogen agonists. Soy-derived food supplements are advised for hormone replacement therapy, prevention of atherosclerosis, age-related cognitive decline and even hormone-dependent cancer, although results from clinical studies are controversial. Whether increased soybean intake can affect the endocrine status and cognitive abilities is largely unknown.
  
  
  OBJECTIVE
  To observe the effects of 1 week of increased soybean intake on sex hormone levels and spatial cognitive abilities in women.
  
  
  METHODS
  16 young healthy female volunteers were asked to eat 900 g of soybeans within 1 week. Salivary testosterone (T), free and total plasma T, salivary and plasma estradiol (E) were measured by radioimmunoassay before and after the study period. Mental rotation (MR) and spatial visualization (SV) psychological tests were done at the days of sampling.
  
  
  RESULTS
  Soybean intake increased total plasma T levels (p < 0.02) while decreasing salivary T (p < 0.01) and not altering free plasma T levels. Salivary and plasma E levels were not changed. The results of MR and SV tests were improved after the study period.
  
  
  CONCLUSIONS
  Short-time increased soybean intake alters the level of total plasma and salivary T and improves spatial cognition in women. Whether this effect is mediated by modulation of estrogen receptors, changes in sex hormone-binding globulin production or changes in activity of steroid-competent enzymes needs further study.
authors.affiliation: Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia. petercelec@hotmail.com
authors.forename: Peter
authors.initials: P
authors.lastname: Celec
authors.forename: Daniela
authors.initials: D
authors.lastname: Ostatníková
authors.forename: Marieta
authors.initials: M
authors.lastname: Cagánová
authors.forename: Svetlana
authors.initials: S
authors.lastname: Zuchová
authors.forename: Július
authors.initials: J
authors.lastname: Hodosy
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Putz
authors.forename: Marián
authors.initials: M
authors.lastname: Bernadic
authors.forename: Matús
authors.initials: M
authors.lastname: Kúdela
mesh_terms: D000328:Adult; D003071:Cognition / Q000187:drug effects*; D019587:Dietary Supplements / Q000600:supply & distribution*; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D011581:Psychological Tests; D011863:Radioimmunoassay; D013025:Glycine max / Q000378:metabolism*; D013739:Testosterone / Q000097:blood / Q000378:metabolism*; D013997:Time Factors
chemical_list: D013739:Testosterone; D004958:Estradiol