Coffee Consumption and Bone Health
A 2002 review4 suggested that there is no overall negative effect of caffeine on bone health, where calcium intakes are adequate. Potentially negative effects were seen in those with insufficient calcium intake or very high coffee consumption (over 9 cups daily).
Four more recent meta analyses5-8 show significant variability in their results. Some results suggest no association between coffee consumption and fracture risk whilst others suggest a potential effect in women and elderly participants in particular.
Additional studies assessing the association between coffee consumption and bone mineral density and fracture risk have also provided inconclusive results. A Swedish study9 suggested that high coffee intake was associated with a small reduction in bone mineral density but not an increased risk of fracture.
Interactions between coffee components and bone health are unclear. Animal models suggest that caffeine intake may result in negative calcium balance through increased calcium excretion, and this may affect bone mineral density10. Human studies have suggested that caffeine may impair the efficiency of calcium absorption, increase calcium excretion in urine, and limit the role of vitamin D in bone too. These effects could reduce bone mineral density and increase the risk of fractures and osteoporosis.
Currently, there are insufficient data to reach a convincing conclusion and further research needs to be conducted.