Study finds heavy coffee drinking may weaken bones in older women, while tea may help
A 10-year study of nearly 10,000 older women found regular tea drinking linked to slightly higher bone density, while drinking more than five cups of coffee a day was linked to lower density.
Researchers at Flinders University in Australia have found that coffee and tea appear to affect bone health differently in older women. The study, published in the journal Nutrients, followed almost 10,000 women aged 65 and older over a 10-year period, examining how their coffee and tea habits related to bone mineral density, a key measure used to assess osteoporosis risk. Osteoporosis affects roughly one in three women over 50 and contributes to millions of fractures worldwide each year.
A decade of tracking
The team drew on data from the Study of Osteoporotic Fractures, in which participants repeatedly reported their beverage habits while researchers used imaging to track bone density changes at the hip and femoral neck — both strongly linked to fracture risk.
Women who drank tea showed slightly higher total hip bone density than non-tea drinkers. The difference was small but statistically significant, and researchers say it could matter when applied across large populations.
Heavy coffee use tied to lower density
Moderate coffee drinking, around two to three cups a day, was not linked to any harm. However, women consuming more than five cups daily had lower bone density. The effects varied with other lifestyle factors: coffee's negative association was stronger among women with higher lifetime alcohol consumption, while tea's apparent benefits were more pronounced in women with obesity.
Co-author Ryan Liu noted that catechins, compounds abundant in tea, may support bone formation and slow bone breakdown, while caffeine in coffee has been shown in lab studies to interfere with calcium absorption and bone metabolism — though these effects are modest and can be reduced by adding milk.
The researchers stressed that the observed differences were modest and do not justify major lifestyle changes. Still, they suggest that regular tea drinking could be a simple way to support bone health, while very high coffee intake, particularly alongside alcohol use, may not be ideal for older women.
