A routine bone scan could one day flag people at risk of brain decline. Here is how the bone-brain link works.

The study looked at spinal bone mineral density, measured from ordinary chest CT scans, and compared it with brain MRI results and cognitive tests over about five years in 715 older adults.

People with lower bone density lost global cognition faster. Their brains also accumulated more white matter hyperintensities, bright spots of damaged wiring, in the corpus callosum, the cable bundle linking the brain’s halves that supports planning and attention, Medscape reported.

White matter acts like electrical cable between brain regions. When it degrades, signals slow. That breakdown is linked to vascular dementia and Alzheimer’s risk.

Crucially, the study does not prove weak bones cause dementia. The researchers say shared underlying factors, possibly vascular or inflammatory, may be degrading both tissues.

Why it matters: chest CTs are already done for lung screening and calcium scoring. If bone density in those scans can double as an early warning for brain decline, doctors could spot at-risk patients sooner and start monitoring earlier.