Dubai, United Arab Emirates (CNN) — Experts say slowing age-related walking has long been seen as a warning sign of increasing weakness in the body that can cause falls and other disabilities. Emerging research with small groups of older adults has also shown that walking slower, year after year, can be an early indicator of cognitive decline.
Studies suggest this may be due to a contraction of the right hippocampus, the part of the brain associated with memory.
But not all signs of cognitive decline indicate dementia later in life, and according to the National Institute on Aging, only 10-20% of people age 65 and older with mild cognitive impairment or mild cognitive impairment develop dementia the following year. “In many cases, symptoms of mild cognitive impairment can persist or even improve,” the institute said.
Now, a new, large-scale study of nearly 17,000 adults over the age of 65 finds that people who report a slower walking pace of 5% or more per year, along with signs of slower mental processing, are more likely to develop dementia. The research was published Tuesday in the journal JAMA Network Open.
“These findings highlight the importance of walking in assessing dementia risk,” wrote reporter Taya Collier, a research associate at the Peninsula Clinical School at Monash University in the Australian state of Victoria.
Who is most at risk of developing dementia?
The new study followed a group of Americans over 65 and Australians over 70 for seven years. Every two years, subjects were asked to take cognitive tests to measure general cognitive decline, memory, processing speed, and verbal fluency.
Twice every two years, participants were also asked to walk a distance of 3 meters, or about 10 feet. The two scores were then averaged to determine a person’s typical gait.
dr. Joe Verghese, a professor of geriatrics and neurology at the Albert Einstein College of Medicine in the Bronx, New York, who was not involved in the study, said the study’s researchers concluded that the highest risk of dementia was recorded in people with “double decline”, or people with dementia. Those who walked more slowly also showed some signs of cognitive decline.
“In addition, people with diplopia were more likely to develop dementia than those with cognitive decline or slow walking alone,” Verghese wrote in an editorial accompanying the study published Tuesday in JAMA.
And a meta-analysis study published in 2020, including about 9,000 American adults, revealed that the dual association between walking speed and memory loss points to dementia later on.
But despite these findings, Verges writes, “gait disturbance has not been seen as an early clinical feature in patients with Alzheimer’s disease.”
Sports can help
And there are things we can do as we age to reverse the brain shrinkage associated with typical aging. Studies have shown that aerobic exercise increases the size of the hippocampus, which improves some aspects of memory.
Located deep in the temporal lobe of the brain, the hippocampus is an oddly shaped organ responsible for learning, consolidating memories, and spatial navigation, such as the ability to remember paths, locations, and directions.
Aerobic exercise increased the volume of the right anterior hippocampus by 2%, reversing the decline of this organ associated with age over one or two years, in a randomized clinical trial started in 2011.
In contrast, people who only stretched had a 1.43% decrease over the same period.