title: Associations of mammographic density with dietary factors in Japanese women.
abstract: BACKGROUND
  A high percentage of mammographic dense area has been strongly associated with a risk of beast cancer. The present cross-sectional study evaluated the relations of percent density with dietary factors, such as fats, protein, dietary fiber, and soy isoflavones.
  
  
  METHODS
  Study subjects were 601 (348 premenopausal and 253 postmenopausal) Japanese women who were recruited from a mammographic screening center. The size of the total breast area and the dense area were measured quantitatively using an automated mammographic mass detection method. Intakes of nutrients were estimated with a validated semiquantitative food-frequency questionnaire.
  
  
  RESULTS
  The crude means of the percent density were 39.2% and 18.9% in premenopausal and postmenopausal women, respectively. There were no significant associations of any dietary factors with the percent density in premenopausal women. In postmenopausal women, percent density was significantly positively associated with intakes of protein, total fat, and saturated fat after controlling for covariates; the increase in the means of percent density were 7.2%, 5.6%, and 9.2% in the highest versus lowest quartile of intakes for protein, total fat, and saturated fat, respectively (P for linear trend were 0.006, 0.04, and 0.01, respectively). Carbohydrate intake was inversely associated with percent density; the mean of percent density was 6.0% lower in the highest versus the lowest quartile of intake (P(trend) = 0.03). The associations of dietary factors with dense area were very similar to those with percent density.
  
  
  CONCLUSIONS
  These dietary factors may have implications for the risk of breast cancer in postmenopausal women.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Gifu University Graduate School of Medicine, 1-1 Yanagido, 501-1194 Gifu, Japan. chisato@cc.gifu-u.ac.jp
authors.forename: Chisato
authors.initials: C
authors.lastname: Nagata
authors.forename: Tomoko
authors.initials: T
authors.lastname: Matsubara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujita
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Nagao
authors.forename: Chiken
authors.initials: C
authors.lastname: Shibuya
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Kashiki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D003430:Cross-Sectional Studies; D004032:Diet; D015930:Diet Records; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008327:Mammography; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause; D012307:Risk Factors