title: Habitual tea consumption and risk of osteoporosis: a prospective study in the women's health initiative observational cohort.
abstract: The purpose of this study was to prospectively investigate associations of habitual drinking of regular tea with bone mineral density and fracture risk. Study participants were a multiethnic postmenopausal cohort (n = 91,465) from the nationwide Women's Health Initiative Observational Study. These women were recruited in the United States and aged 50-79 years at the time of enrollment (1994-1998). The average follow-up time was 4.1 years. Habitual consumption of regular tea was assessed with a structured questionnaire at baseline. Clinical fractures during the follow-up were reported in questionnaires, and hip fractures were further confirmed by reviewing medical records. Bone mineral density measurements were conducted among a subgroup of women (n = 4,979) at three Women's Health Initiative bone mineral density centers using dual-energy x-ray absorptiometry. Multivariate analyses suggested a positive trend of increased total body bone mineral density with tea drinking (p < 0.05). However, results from the Cox proportional hazard models did not show any significant association between tea drinking and the risk of fractures at the hip and forearm/wrist. In conclusion, the results from this study indicate that the effect of habitual tea drinking on bone density is small and does not significantly alter the risk of fractures among the US postmenopausal population.
authors.affiliation: Arizona College of Public Health, University of Arizona, Tucson, AZ 85716, USA. zchen@u.arizona.edu
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: M B
authors.initials: MB
authors.lastname: Pettinger
authors.forename: C
authors.initials: C
authors.lastname: Ritenbaugh
authors.forename: A Z
authors.initials: AZ
authors.lastname: LaCroix
authors.forename: J
authors.initials: J
authors.lastname: Robbins
authors.forename: B J
authors.initials: BJ
authors.lastname: Caan
authors.forename: D H
authors.initials: DH
authors.lastname: Barad
authors.forename: I A
authors.initials: IA
authors.lastname: Hakim
mesh_terms: D000368:Aged; D015519:Bone Density; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000627:therapeutic use; D016001:Confidence Intervals; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013662:Tea; D014481:United States / Q000453:epidemiology; D016387:Women's Health
chemical_list: D002136:Calcium, Dietary; D013662:Tea