Dubai, United Arab Emirates (CNN) — Experts say the slowing down of age-related walking has long been seen as a warning sign of increasing weakness in the body that may cause falls and other disabilities. Emerging research involving small groups of older adults has also revealed that slower walking, year after year, may be an early indicator of cognitive decline.
Studies suggest that 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 suggest dementia later on, and only 10-20% of people age 65 and older with mild cognitive impairment or mild cognitive impairment develop dementia the following year, according to the National Institute on Aging. “In many cases, symptoms of mild cognitive impairment may remain 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 slower walking pace of 5% or more per year, along with signs of slower mental processing, are more likely to develop dementia. The study was published in the journal JAMA Network Open, on Tuesday.
“These findings highlight the importance of walking for assessing dementia risk,” wrote reporter Taya Collier, a research fellow 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 the age of 65 and Australians over the age of 70, for seven years. Every two years, study 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 metres, or about 10 feet. The two scores were then averaged to determine a person’s typical walking manner.
Dr. Joe Verghese, a professor of geriatrics and neurology at Albert Einstein College of Medicine in the Bronx, New York, who was not involved in the study, said that the study’s researchers concluded that the highest risk of dementia was recorded in people with “double deterioration,” or people with dementia. Those who walked more slowly also showed some signs of cognitive decline.
“In addition, people with a 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 in JAMA Tuesday.
And a meta-analysis study published in 2020, including about 9,000 American adults, revealed that the double association between walking speed and memory decline suggests dementia later on.
But despite these findings, Verges writes, “walking impairment has not been seen as an early clinical feature in Alzheimer’s patients.”
Sports can help
And there are things we can do as we age to reverse the brain shrinkage that accompanies typical aging. Studies have found that aerobic exercise increases the size of the hippocampus, which enhances some aspects of memory.
The hippocampus, located deep in the brain’s temporal lobe, is an oddly shaped organ responsible for learning, the consolidation of 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%, thus reversing the decline in this organ associated with age for one or two years, during a randomized clinical trial, established in 2011.
In contrast, people who only stretched had a 1.43% decrease in the same time period.