Older people who walk slowly may be at greater risk of Alzheimer's even if they do not show symptoms of the neurodegenerative disease, a new study has claimed.
How fast elderly people walk may be related to the amount of amyloid they have built up in their brains, researchers said.
Amyloid plaques consist of dense deposits of a protein called beta amyloid, and their progressive buildup in the brain has been associated with the development of Alzheimer's disease.
"It's possible that having subtle walking disturbances in addition to memory concerns may signal Alzheimer's disease, even before people show any clinical symptoms," said Natalia del Campo of the University Hospital Toulouse in France.
Researchers conducted the study on 128 people with an average age of 76 who did not have dementia but were considered at high risk for developing it because they had some concerns about their memory.
The participants had positron emission tomography (PET) scans of their brains to measure amyloid plaques in the brain.
Of the participants, 48 per cent had a level of amyloid often associated with dementia.
Participants were also tested on thinking and memory skills and how well they could complete everyday activities. A total of 46 per cent of the participants had mild cognitive impairment, which can be a precursor to the dementia that occurs in Alzheimer's disease.
Walking speed was measured with a standard test that times people on how fast they can walk about 13 feet at their usual pace.
The average walking speed was 3.48 feet per second. All but two of the participants tested in the normal range of walking speed.
The researchers found an association between slow walking speed and amyloid in several areas of the brain, including the putamen, a key region involved in motor function.
They compared how fast people walked both with and without taking into account the amount of amyloid and found that the amyloid level accounted for up to 9 per cent of the difference in walking speed.
The relationship between amyloid levels and walking speed did not change when researchers took into account age, education level, or amount of memory problems.
The findings were published in the journal Neurology.
