title: Milk intake and risk of mortality and fractures in women and men: cohort studies.
abstract: OBJECTIVE
  To examine whether high milk consumption is associated with mortality and fractures in women and men.
  
  
  METHODS
  Cohort studies.
  
  
  METHODS
  Three counties in central Sweden.
  
  
  METHODS
  Two large Swedish cohorts, one with 61,433 women (39-74 years at baseline 1987-90) and one with 45,339 men (45-79 years at baseline 1997), were administered food frequency questionnaires. The women responded to a second food frequency questionnaire in 1997.
  
  
  METHODS
  Multivariable survival models were applied to determine the association between milk consumption and time to mortality or fracture.
  
  
  RESULTS
  During a mean follow-up of 20.1 years, 15,541 women died and 17,252 had a fracture, of whom 4259 had a hip fracture. In the male cohort with a mean follow-up of 11.2 years, 10,112 men died and 5066 had a fracture, with 1166 hip fracture cases. In women the adjusted mortality hazard ratio for three or more glasses of milk a day compared with less than one glass a day was 1.93 (95% confidence interval 1.80 to 2.06). For every glass of milk, the adjusted hazard ratio of all cause mortality was 1.15 (1.13 to 1.17) in women and 1.03 (1.01 to 1.04) in men. For every glass of milk in women no reduction was observed in fracture risk with higher milk consumption for any fracture (1.02, 1.00 to 1.04) or for hip fracture (1.09, 1.05 to 1.13). The corresponding adjusted hazard ratios in men were 1.01 (0.99 to 1.03) and 1.03 (0.99 to 1.07). In subsamples of two additional cohorts, one in males and one in females, a positive association was seen between milk intake and both urine 8-iso-PGF2α (a biomarker of oxidative stress) and serum interleukin 6 (a main inflammatory biomarker).
  
  
  CONCLUSIONS
  High milk intake was associated with higher mortality in one cohort of women and in another cohort of men, and with higher fracture incidence in women. Given the observational study designs with the inherent possibility of residual confounding and reverse causation phenomena, a cautious interpretation of the results is recommended.
authors.affiliation: Department of Surgical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden karl.michaelsson@surgsci.uu.se.
authors.forename: Karl
authors.initials: K
authors.lastname: Michaëlsson
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
authors.affiliation: Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Sophie
authors.initials: S
authors.lastname: Langenskiöld
authors.affiliation: Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Samar
authors.initials: S
authors.lastname: Basu
authors.affiliation: Department of Surgical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden Swedish National Food Agency, Uppsala, Sweden.
authors.forename: Eva
authors.initials: E
authors.lastname: Warensjö Lemming
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Melhus
authors.affiliation: Department of Surgical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
authors.forename: Liisa
authors.initials: L
authors.lastname: Byberg
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D004032:Diet / Q000009:adverse effects*; D004034:Diet Surveys; D004327:Drinking Behavior; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008892:Milk / Q000009:adverse effects*; D009026:Mortality; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D013548:Sweden / Q000453:epidemiology