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Slower walking with age has always been a warning sign of increasing frailty, which can lead to falls and other disabilities, experts say. Emerging research in small groups of older subjects has also found that a slower gait from year to year may be an early sign of cognitive decline.
This may be due to the shrinking of the right hippocampus, which is the part of the brain associated with memory, studies show.
But not all signs of cognitive decline predict later dementia — only 10% to 20% of people age 65 or older with mild cognitive impairment or MCI will develop dementia within the next year, according to the National Institute on Aging. “In many cases, MCI symptoms may stay the same or even improve,” the institute states.
Now, a large new study of nearly 17,000 adults over the age of 65 finds that people who walk about 5% slower or more each year while showing signs of slowed mental processing were the most likely to develop dementia. The study was published Tuesday in the journal JAMA Network Open.
“These findings underscore the importance of walking in assessing dementia risk,” wrote corresponding author Taya Collyer, a researcher at the Peninsula Clinical School at Monash University in Victoria, Australia.
The new study followed a group of Americans over 65 and Australians over 70 for seven years. Every two years, study participants were asked to take cognitive tests that measured overall cognitive decline, memory, processing speed and verbal fluency.
Twice every two years, subjects also had to walk 3 meters, or about 10 feet. The two results were then averaged to determine the person’s typical gait.
At the end of the study, the researchers found that the highest risk of dementia was for ‘double decliners’, that is, people who not only walked slower, but also showed signs of decline. cognitive, said Dr. Joe Verghese, professor of geriatrics and neurology. at Albert Einstein College of Medicine in the Bronx, New York, who did not participate in the study.
“Additionally, dual decliners had a higher risk of dementia than those who had either gait or cognitive decline alone,” Verghese wrote in an accompanying editorial published Tuesday in the journal JAMA.
A dual association between walking speed and memory decline is predictive of later dementia, according to a 2020 meta-analysis of nearly 9,000 American adults.
Yet despite these findings, “gait dysfunction has not been considered an early clinical feature in patients with Alzheimer’s disease,” Verghese wrote.
There are things we can do as we age to reverse the brain shrinkage that accompanies typical aging. Studies have shown that aerobic exercise increases the size of the hippocampus, increasing certain aspects of memory.
Buried deep in the temporal lobe of the brain, the hippocampus is an oddly shaped organ that is responsible for learning, consolidation of memories and spatial navigation, such as the ability to remember directions, locations and directions.
Aerobic exercise training increased right anterior hippocampus volume by 2%, reversing age-related loss in the organ by one to two years in a 2011 randomized clinical trial. By comparison, people who only did stretching exercises experienced an approximate decline of about 1.43% over the same period.
Aerobic exercise means with “air” and is a type of training where heart rate and breathing increase, but not so much that you cannot continue to function. Types of aerobic exercise can include brisk walking, swimming, running, biking, dancing, and kickboxing, as well as any cardio machines at your local gym, such as a treadmill, elliptical, rowing machine or stairlift.