title: Seaweed intake and urinary sex hormone levels in preschool Japanese children.
abstract: OBJECTIVE
  We investigated whether seaweed intake is associated with sex steroid levels in young Japanese children.
  
  
  METHODS
  The design of the study was cross-sectional and it was conducted in October-November 2006. Subjects were substantially healthy preschoolers, 230 boys and 198 girls, aged 3-6 years. Dietary data, including seaweed intake, were assessed using 3-day dietary records covering 2 consecutive weekdays and 1 weekend day. Urinary estrone, estradiol, testosterone, and 5-androstene-3β,17α diol levels were measured by liquid chromatography-electrospray ionization tandem mass spectrometry. Urinary dehydroepiandrosterone level was measured with a radioimmunoassay. Steroid hormones were adjusted for urinary creatinine levels.
  
  
  RESULTS
  Spearman's correlation coefficient between seaweed intake and estrone level was -0.144 (p = 0.030) in boys and -0.147 (p = 0.041) in girls after adjustments for age, BMI, and total energy intake. Seaweed intake was neither associated with estradiol, testosterone, 3β,17α-AED nor with DHEA among boys and girls.
  
  
  CONCLUSIONS
  The negative association between seaweed intake and estrone level suggests that dietary seaweed intake might affect estrogen metabolism in childhood.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan. dr_keiko@gifu-u.ac.jp
authors.forename: Keiko
authors.initials: K
authors.lastname: Wada
authors.forename: Kozue
authors.initials: K
authors.lastname: Nakamura
authors.forename: Yuya
authors.initials: Y
authors.lastname: Tamai
authors.forename: Michiko
authors.initials: M
authors.lastname: Tsuji
authors.forename: Kaori
authors.initials: K
authors.lastname: Watanabe
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ando
authors.forename: Chisato
authors.initials: C
authors.lastname: Nagata
mesh_terms: D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004435:Eating; D005260:Female; D012739:Gonadal Steroid Hormones / Q000652:urine*; D006801:Humans; D007564:Japan; D008297:Male; D012624:Seaweed
chemical_list: D012739:Gonadal Steroid Hormones