title: Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation.
abstract: OBJECTIVE
  Caffeine consumption has been proposed as a risk factor for bone loss in postmenopausal women. Past epidemiologic studies on caffeine and bone have been confounded by covariates including cigarette and alcohol use, differing levels of physical activity and hormone replacement therapy. The purpose of the study was to use a longitudinal design to determine the relationship between habitual dietary caffeine intake and postmenopausal bone status.
  
  
  METHODS
  Data were collected at two time points separated by two years; 138 women with little or no exposure to tobacco or to drugs known to affect bone status were seen at Visit 1, and 112 returned for Visit 2. Ninety-two of these subjects had received no drugs known to affect bone status over the two-year interval and were kept in the sample. Nutrient and caffeine intake were assessed from three-day diet records. Bone measurements were made by dual energy x-ray absorptiometry (DXA).
  
  
  RESULTS
  Correlation analyses indicated no association between dietary caffeine intake and total body or femoral neck bone density or bone mass. Similarly, no associations were found between caffeine consumption and longitudinal changes in total body or femoral neck bone measurements. These results held true both with and without statistical adjustment for calcium intake.
  
  
  CONCLUSIONS
  This study does not support the idea that caffeine is a risk factor for bone loss in healthy postmenopausal women.
authors.affiliation: Department of Health Evaluation Sciences, Pennsylvania State College of Medicine and University Hospitals, Pennsylvania State Geisinger Health System, Milton S. Hershey Medical Center, Hershey, USA.
authors.forename: T
authors.initials: T
authors.lastname: Lloyd
authors.forename: N
authors.initials: N
authors.lastname: Johnson-Rollings
authors.forename: D F
authors.initials: DF
authors.lastname: Eggli
authors.forename: K
authors.initials: K
authors.lastname: Kieselhorst
authors.forename: E A
authors.initials: EA
authors.lastname: Mauger
authors.forename: D C
authors.initials: DC
authors.lastname: Cusatis
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density; D002110:Caffeine / Q000008:administration & dosage*; D002136:Calcium, Dietary / Q000008:administration & dosage; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage; D002149:Energy Intake; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D009747:Nutritional Physiological Phenomena; D017698:Postmenopause
chemical_list: D002136:Calcium, Dietary; D004044:Dietary Proteins; D002110:Caffeine