Daily Tea or Coffee Intake Linked to Bone Density in Older Women

Nearly 10,000 postmenopausal women were followed for 10 years in a study examining how tea and coffee consumption relate to bone mineral density (BMD). Researchers from Flinders University discovered that tea drinkers exhibited slightly stronger hip bones compared to non-tea drinkers, while consuming more than five cups of coffee daily correlated with lower BMD.

Study Details on Bone Density and Beverage Intake

The research analyzed data from the Study of Osteoporotic Fractures in the United States, focusing on women aged 65 and older. Participants’ coffee and tea consumption, along with bone density measurements at the hip and femoral neck, were repeatedly recorded over the study period. Bone density was assessed using dual-energy X-ray absorptiometry (DXA), the standard diagnostic tool for osteoporosis.

Tea drinkers showed a modest but statistically significant increase in total hip BMD of approximately 0.003 g/cm² compared to those who did not drink tea. Adjunct Associate Professor Enwu Liu from Flinders University’s College of Medicine and Public Health noted that even small improvements in bone density could reduce fracture rates across large populations.

The Complex Relationship Between Coffee and Bone Health

Coffee intake presented a nuanced association with bone density. Moderate consumption of two to three cups daily showed no significant impact on bone health. However, intake exceeding five cups per day was linked to decreased bone mineral density. Co-author Ryan Liu highlighted that caffeine can interfere with calcium absorption and bone metabolism, although these effects may be mitigated by adding milk to coffee.

Previous studies have yielded mixed results on caffeine’s effects on bones, with some indicating increased fracture risk at high consumption levels and others finding no significant impact. Variations in diet, calcium intake, genetics, exercise, and alcohol consumption may contribute to these discrepancies. This study found that women with higher lifetime alcohol use experienced stronger negative associations between coffee consumption and bone density.

Additional Findings and Study Limitations

Tea consumption appeared especially beneficial for women with obesity. Despite these findings, the researchers cautioned against interpreting the results as a directive to cease coffee consumption or to increase tea intake excessively. Associate Professor Liu stated that moderate tea drinking could support bone health, while very high coffee consumption might be less advisable, particularly for women who consume alcohol.

The study emphasized that coffee and tea are minor factors in the broader context of bone health, where calcium, vitamin D, resistance exercise, and smoking cessation play more critical roles in osteoporosis prevention. Limitations include the predominantly White U.S. female participant group, self-reported beverage intake, and lack of detail on cup size, brewing strength, or specialty coffee types. Nevertheless, the study’s large sample size and long follow-up period distinguish it within osteoporosis research.