title: Association between dietary fiber, water and magnesium intake and functional constipation among young Japanese women.
abstract: OBJECTIVE
  Most research on constipation has focused on dietary fiber intake. Here, we examined the intake of water and magnesium, nutrients possibly associated with constipation, as well as that of dietary fiber in relation to constipation.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A total of 3835 female Japanese dietetic students aged 18-20 years from 53 institutions in Japan.
  
  
  METHODS
  Dietary intake was estimated with a validated, self-administered diet history questionnaire. Functional constipation was defined using the Rome I criteria.
  
  
  RESULTS
  The prevalence of functional constipation was 26.2%. Neither dietary fiber intake (mean=6.4 g/4186 kJ) nor intakes of total water and water from fluids were associated with constipation. Conversely, low intake of water from foods was associated with an increasing prevalence of constipation. In comparison with women in the first (lowest) quintile, the multivariate adjusted odds ratio (OR) (95% confidence interval (CI)) for women in the second, third, fourth, and fifth quintiles were 0.72 (0.57, 0.90), 0.78 (0.62, 0.98), 0.71 (0.56, 0.89), and 0.77 (0.61, 0.97), respectively (P for trend=0.04). Additionally, low magnesium intake was associated with increasing prevalence of constipation. Compared with women in the first quintile, the multivariate adjusted OR (95% CI) for women in the second, third, fourth and fifth quintiles were 0.70 (0.56, 0.88), 0.75 (0.60, 0.95), 0.73 (0.58, 0.92) and 0.79 (0.63, 0.996), respectively (P for trend=0.09).
  
  
  CONCLUSIONS
  Low intakes of water from foods and magnesium are independently associated with an increasing prevalence of functional constipation among a population whose dietary fiber intake is relatively low.
authors.affiliation: Nutritional Epidemiology Program, National Institute of Health and Nutrition, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Sasaki
authors.forename: H
authors.initials: H
authors.lastname: Okubo
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Hosoi
authors.forename: M
authors.initials: M
authors.lastname: Itabashi
mesh_terms: D000293:Adolescent; D000328:Adult; D016001:Confidence Intervals; D003248:Constipation / Q000453:epidemiology* / Q000209:etiology; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D004043:Dietary Fiber / Q000008:administration & dosage* / Q000378:metabolism; D004326:Drinking; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008019:Life Style; D008274:Magnesium / Q000008:administration & dosage* / Q000378:metabolism; D015999:Multivariate Analysis; D016017:Odds Ratio; D015995:Prevalence; D012650:Self Disclosure; D013334:Students; D011795:Surveys and Questionnaires; D014867:Water / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: D004043:Dietary Fiber; D014867:Water; D008274:Magnesium