ORIGINAL RESEARCH COMMUNICATION
Tea drinking is associated with benefits on bone density in older women1,2,3
Amanda Devine, Jonathan M Hodgson, Ian M Dick and Richard L Prince
1 From the School of Medicine and Pharmacology, University of Western Australia, Perth, Australia (JMH, IMD, and RLP); the Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, Australia (IMD and RLP); and the School of Exercise, Biomedical and Health Science, Edith Cowan University, Joondalup, Australia (AD)
Background: Impaired hip structure assessed by dual-energy X-ray absorptiometry (DXA) areal bone mineral density (aBMD) is an independent predictor for osteoporotic hip fracture. Some studies suggest that tea intake may protect against bone loss.
Objective: Using both cross-sectional and longitudinal study designs, we examined the relation of tea consumption with hip structure.
Design: Randomly selected women (n = 1500) aged 70–85 y participated in a 5-y prospective trial to evaluate whether oral calcium supplements prevent osteoporotic fractures. aBMD at the hip was measured at years 1 and 5 with DXA. A cross-sectional analysis of 1027 of these women at 5 y assessed the relation of usual tea intake, measured by using a questionnaire, with aBMD. A prospective analysis of 164 women assessed the relation of tea intake at baseline, measured by using a 24-h dietary recall, with change in aBMD from years 1 to 5.
Results: In the cross-sectional analysis, total hip aBMD was 2.8% greater in tea drinkers (: 806; 95% CI: 797, 815 mg/cm2) than in non-tea drinkers (784; 764, 803 mg/cm2) (P < 0.05). In the prospective analysis over 4 y, tea drinkers lost an average of 1.6% of their total hip aBMD (–32; –45, –19 mg/cm2), but non-tea drinkers lost 4.0% (–13; –20, –5 mg/cm2) (P < 0.05). Adjustment for covariates did not influence the interpretation of results.
Conclusion: Tea drinking is associated with preservation of hip structure in elderly women. This finding provides further evidence of the beneficial effects of tea consumption on the skeleton.
Key Words: Tea drinking • cross-sectional study • prospective study • bone mineral density • fracture • elderly women
American Journal of Clinical Nutrition, Vol. 86, No. 4, 1243-1247, October 2007
© 2007 American Society for Nutrition