Older women who fancy a cup of tea, or several, throughout the day, may be giving a boost to the health of their bones, while a high coffee intake may be linked to lower bone density, a new long-term study indicates.

A decade-long Flinders University study published in the journal Nutrients was based on a study of 10,000 women aged 65 and over, designed to examine whether regular or increased tea and coffee consumption were associated with changes to bone mineral density (BMD), a key indicator of osteoporosis and fracture risk.

Osteoporosis affects around one in three women over the age of 50 worldwide and is a major cause of fractures, particularly in older age. Given the widespread consumption of coffee and tea globally, researchers aimed to clarify their long-term relationship with bone health, which experts say is an area where previous evidence has been mixed and the results of previous studies largely inconclusive.

Data drawn from the long-running Study of Osteoporotic Fractures helped researchers analyse repeated measurements of tea and coffee intake alongside bone density scans of the hip and femoral neck, two areas closely linked to fracture risk.

The study found that women who drank tea had slightly higher total hip BMD compared with those who did not drink tea. Authors of the study say that while the difference was small, it was statistically significant.

Lead author and Flinders University Adjunct Associate Professor Enwu Liu said even modest changes in bone density could have broader public health implications.

“Even small improvements in bone density can translate into fewer fractures across large groups,” Professor Liu said.

On the other hand, coffee consumption showed more varied results. Moderate intake, which in the study was defined as around two to three cups per day, was not associated with lower bone density. However, women who consumed more than five cups of coffee a day were found to have lower BMD over time.

The study also identified differences among subgroups. Higher lifetime alcohol consumption appeared to amplify the negative association between heavy coffee intake and bone density, while the positive association with tea consumption was more evident among women with an obese body mass index.

Co-author Ryan Yan Liu said compounds found in tea, such as catechins, may help promote bone formation and reduce bone loss. By contrast, caffeine in coffee has been shown in laboratory studies to interfere with calcium absorption, though the effect can be reduced when coffee is consumed with milk.

The researchers emphasised that the findings do not suggest people need to drastically change their habits. The observed differences in bone density were relatively small and should be considered alongside established factors such as adequate calcium and vitamin D intake.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.