Drinking more than five cups of coffee a day may be linked to lower bone mineral density in older women, while regular tea consumption shows a modest association with higher hip bone density, according to a 10-year study published in the journal Nutrients and highlighted by Flinders University.
Ten-Year Study Tracks Nearly 10,000 Older Women
Researchers at Flinders University analyzed data from the Study of Osteoporotic Fractures, tracking 9,704 women aged 65 and older over a decade. The investigation aimed to clarify how regular consumption of coffee and tea relates to bone mineral density (BMD) at the total hip and femoral neck—two skeletal sites closely linked to fracture risk. Osteoporosis affects approximately one in three women over age 50 globally, making beverage habits a subject of significant public health interest given how widely coffee and tea are consumed.
During the study period, participants repeatedly reported their beverage intake while researchers measured changes in their bone density using advanced imaging. Across the decade, average femoral neck BMD dropped from about 0.65 grams per square centimeter to 0.62, while total hip BMD fell from approximately 0.76 to 0.73. In their main overall analysis, researchers found no statistically significant linear association between overall coffee intake and bone mineral density at these sites.
Heavy Coffee Consumption Versus Moderate Intake
A distinct pattern emerged when investigators examined specific consumption thresholds. Women who drank a moderate amount of coffee—roughly two to three cups per day—did not experience negative effects on bone health. However, participants who consumed more than five cups daily exhibited lower bone mineral density, suggesting potential risks tied to very high coffee consumption.
According to Ryan Liu from Flinders University, laboratory studies indicate that caffeine can interfere with calcium absorption and disrupt bone metabolism, though these biological effects are typically minor and can often be counterbalanced by adding milk. The Flinders University team also observed that the relationship between coffee and bone density varied across subgroups. Women with higher lifetime alcohol consumption showed a stronger negative association between heavy coffee intake and femoral neck BMD.
Tea Consumption and Bone Mineral Density
In contrast to heavy coffee consumption, the Flinders University study found that women who drank tea had slightly higher total hip BMD than non-tea drinkers. After rigorous statistical adjustments, the observed difference amounted to roughly 0.003 grams per square centimeter, with tea drinkers averaging 0.718 compared to 0.715 for non-drinkers.
While the difference is tiny and falls below the threshold considered clinically meaningful for an individual patient, researchers emphasize that even small shifts could reduce fracture rates across large populations. Ryan Liu noted that catechins—natural compounds abundant in tea—may support bone-forming cells and slow bone breakdown. Furthermore, the apparent benefits of tea appeared more pronounced among women with obesity, though researchers noted these subgroup observations require confirmation through future studies.
Clinical Implications and Daily Habits
Study authors stress that their findings do not justify drastic lifestyle changes or abandoning daily routines. Adjunct Associate Professor Enwu Liu pointed out that the results do not mean individuals must give up coffee entirely or start drinking tea in excessive quantities. Instead, moderate coffee consumption appears safe, while very high intake warrants caution—particularly for individuals with higher alcohol consumption.
While calcium and vitamin D remain the foundational pillars of skeletal health, researchers conclude that daily beverage choices can play a supportive role. For older women, enjoying a regular cup of tea offers a comforting ritual that may provide a small measure of support for long-term bone health.