Scientists have long believed that a slower walking pace in older people may be linked to dementia.
Now a team of researchers have identified the changes in the brain which explain why.
They discovered that people who developed slowed walking show a shrinkage of their right hippocampus.
This area of the brain, which is similar in shape to a seahorse, is primarily associated with memory and the ability to maintain posture.
The findings suggest dementia could be treated earlier if doctors regularly measure the walking speeds of older patients and watch for changes over time.
That's according to a 14-year study carried out by experts at the University of Pittsburgh Graduate School of Public Health.