Walking slowly may be an indicator of dementia, say scientists who found that older adults who experience a slowing gait also suffered shrinkage of a part of the brain linked with memory and spatial orientation.
Researchers determined that participants with a slowing gait and cognitive decline also experienced shrinkage of their right hippocampus, an area of the brain important to both memory and spatial orientation.
It was the only area of the brain where the researchers found a shrinking volume to be related to both gait slowing and cognitive impairment.
They also found gait slowing over an extended period of time to be a stronger predictor of cognitive decline than simply slowing at a single time point, which is what other, similar research evaluated.
All the participants slowed over time, but those who slowed by 0.1 seconds more per year than their peers were 47 per cent more likely to develop cognitive impairment.
The finding held even when the researchers took into account slowing due to muscle weakness, knee pain and diseases, including diabetes, heart disease and hypertension.
"A fraction of a second is subtle, but over 14 years, or even less, you would notice," said Andrea Russo, assistant professor at University of Pittsburgh.
Researchers assessed about 175 older adults aged between 70 and 79. At the beginning of the study, the participants were all in good mental health and had normal brain scans.
Multiple times over 14 years, the participants walked an 18-foot stretch of hallway at what they deemed a normal walking pace while a research assistant timed them.
At the conclusion of the study, researchers tested the participants again for their mental acuity and received brain scans.
The study was published in the journal Neurology.