Women over 65 who drink more than five cups of coffee a day may have lower bone mineral density, research suggests. The study found a link between heavy coffee intake and weaker bones, but it does not prove coffee causes bone loss.

Published in the journal Nutrients, the research found no such concern among women drinking two to three cups a day. However, the study did not establish what happens to bone density among those drinking three to five cups.

The analysis nevertheless pointed to a possible tipping point at more than five cups a day. Although there was no significant overall link between coffee intake and bone density, women drinking more than five cups appeared to have lower bone density.

Researchers from Flinders University drew on the Study of Osteoporotic Fractures, following 9,704 women over 10 years. They tracked coffee and tea habits alongside bone scans.

The scans focused on the hip and femoral neck, important fracture sites in older age. Statistical models also accounted for factors including activity levels and health conditions.

The negative association was more pronounced among women who also drank alcohol, although the amount of alcohol involved was not specified. The researchers did not say how much bone density declined among heavy coffee drinkers.

Women face a higher risk of osteoporosis than men, partly because of lower bone mass. Bone loss also speeds up after the menopause, making later life important for protecting bone health.

Tea Showed a Different Pattern

Tea drinkers tended to have higher bone density at the hip, an effect that was more noticeable in women with obesity. Study co-author Ryan Liu said catechins in tea may help build bone and slow bone breakdown.

Coffee's caffeine works differently, Liu explained. Laboratory studies show it can interfere with calcium absorption, although the effect is described as small.

Liu said the findings should not alarm coffee drinkers. People do not need to give up coffee or start drinking large amounts of tea because of the results.

Moderate tea intake could be a useful way to support bone health. Very high coffee intake might not be ideal, particularly for women who also drink alcohol.

Why the Findings Matter

Coffee and tea were chosen because they are among the world's most widely consumed drinks. Diet plays a crucial role in preventing long-term disease, the research team said.

Around one in three women and one in five men aged 50 and over worldwide will experience an osteoporosis-related fracture. In the United States, the number of older adults with low bone density is rising.

Researchers expect this figure to grow by 17.2 million by 2030, adding pressure to stretched health budgets. The findings come as concerns about bone health among ageing populations grow.

The Caveats That Matter

Nutrition specialist Lisa Young said the findings should be treated with care. She noted that the study shows an association, not proof, that coffee weakens bones or tea strengthens them.

Young pointed to limitations including differences in lifestyle among participants. She also noted that the study focused on bone density rather than actual fractures.

The researchers also noted that participants were almost entirely older White women in the US, limiting how broadly the findings can be applied.

That distinction is important because lower bone density does not automatically mean someone will suffer a fracture. The research therefore cannot establish whether drinking more coffee directly increases the risk of broken bones.

Even so, Young said moderate coffee drinking still appears safe. The most effective steps remain getting enough calcium and vitamin D, staying active, avoiding smoking and limiting excess alcohol.

Symptoms of osteoporosis and bone loss can vary and may include back pain, loss of height and a stooped posture. Anyone concerned about their bone health should seek medical advice.

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