Walking speed in older age may provide clues about the condition of the brain. A new study found that people over age 80 who walked at the fastest pace had about a 51% lower risk of developing cognitive impairment in subsequent years compared with peers who walked more slowly. Additional groups examined in the study also showed slower declines in memory and other cognitive functions, as well as better preservation of hippocampal volume.
The study, published in the journal Neurology, was led by researchers from the Renaissance School of Medicine at Stony Brook University and the Albert Einstein College of Medicine in New York. It was based on several groups of people over age 80 from the United States, Europe and Asia who had not been diagnosed with Alzheimer’s disease or dementia at the start of the study.
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Walking speed in older age may provide clues about the condition of the brain
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Researchers called the fastest participants “super movers.” They were defined as people over age 80 whose walking speed was at least 1.5 standard deviations above the age- and sex-adjusted average. According to a report on the study in the San Francisco Chronicle, they walked at a pace of about 1.3 meters per second, or roughly 4.7 kilometers per hour.
Previous studies found that "super movers" tend to have lower rates of chronic disease, healthier lifestyles and younger biological ages. In the current study, researchers sought to determine whether these advantages were also reflected in brain health: whether their risk of cognitive impairment was lower, how their cognitive abilities changed over the years and what could be learned from their brain structure.
The main analysis was based on five studies from the international Health and Retirement Study network and included 3,989 participants. Their average age at the beginning of the studies ranged from 83.6 to 84.4, and the percentage of women ranged from 47% to 65%. Of all participants, 358 were classified as "super movers.
To assess the risk of developing cognitive impairment, researchers excluded 274 participants who already had such impairment at the beginning of follow-up. Cognitive impairment was defined as a score more than 1.5 standard deviations below the age-adjusted average on one of the cognitive tests, along with impaired ability to perform complex daily activities.
Previous studies found that 'super mover' tend to have lower rates of chronic disease
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After follow-up periods ranging from 3.4 to 5.4 years, researchers found that "super movers" had a 51% lower risk of developing cognitive impairment compared with other participants. The hazard ratio was 0.49, with a 95% confidence interval ranging from 0.28 to 0.71. The calculations were adjusted for age and sex, and the results from the studies were combined in a meta-analysis.
Slower memory decline
To examine cognitive changes and brain structure in greater depth, researchers also used data from the LonGenity study, which included 197 participants. Their average age at the start of the study was 84.6, and 57.8% were women. "super movers" showed slower declines both in memory and in non-memory-related cognitive functions. Researchers also examined the trajectory of changes in overall cognitive function before and after age 80, as well as differences in cortical thickness and hippocampal volume. The analyses were adjusted for age, sex, education and parental longevity.
The findings indicated preservation of hippocampal volume in certain areas among "super movers". The hippocampus is a brain region that plays a central role in memory and its volume tends to shrink in people with Alzheimer’s disease. Researchers also examined data from the Rush Memory and Aging Project, which included 692 participants. Their average age at the beginning of the study was 85.6, and 68.9% were women. "Super movers" demonstrated better cognitive function before death, and the prevalence of Alzheimer’s disease and dementia among them was lower.
However, postmortem examinations found no differences between "super movers" and other participants in pathological findings associated with dementia. According to the San Francisco Chronicle report, "super movers'" brains also showed some accumulation of amyloid protein, similar to those of participants who walked more slowly. Amyloid plaques are considered one of the hallmarks of Alzheimer’s disease.
'Super movers' did not show clinical symptoms of Alzheimer’s
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Despite the accumulation, "super movers" did not show clinical symptoms of Alzheimer’s. Researchers said they may have been more resilient to the effects of brain changes or may have had greater cognitive reserve, which helped protect them from developing symptoms.
Dr. Sandra Benizri, a neurologist at Assuta Ramat Hahayal, said this was one of the study’s important findings. “People who walked faster showed slower cognitive decline, but when their brains were examined after death, there were no major differences. They also had amyloid deposits, as are found in Alzheimer’s patients, but they did not develop symptoms of the disease,” she said.
She said the finding shows that the presence of amyloid in the brain does not necessarily lead to cognitive decline. “There are apparently things we can do to help the brain cope with amyloid accumulation, which is a marker of brain aging. We may have the ability to influence how aging manifests itself.”
Dr. Sandra BenizriThe two-way link between walking and the brain
Physical activity is known to help maintain the health of the body and brain, but Dr. Benizri said several mechanisms may explain the connection found in the study.
“People are sometimes surprised when they complain about memory decline and a specialist recommends that they go for walks,” Dr. Benizri said. “But we know that physical activity protects the brain and cognitive function. One of the main explanations is that it increases blood flow to the brain, improves blood vessel health and helps regulate blood sugar levels. Good blood flow is an important component of brain function and maintaining its health.”
She said the effects may extend beyond improved blood flow. “Physical activity also encourages the release of hormones that improve mood and reduce pain. There is a close connection between mood, anxiety and cognitive decline, so this may also have an effect. Additional mechanisms are likely involved here as well,” she said.
The relationship between walking and brain function may work in both directions. On one hand, physical activity and good physical fitness may help preserve the brain. On the other, the ability to walk quickly may indicate that cognitive and motor functions were already intact to begin with.
“Walking is an activity that also requires cognitive function,” Dr. Benizri explained. “One of the things that can be affected by cognitive decline is the ability to perform a sequence of motor actions. Walking properly requires a combination of a healthy motor system and a healthy cognitive system. Therefore, fast walking may indicate good physical fitness, which protects the brain, but it may also reflect good cognitive status from the outset.”
The relationship between walking and brain function may work in both directions
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You do not have to start walking faster
According to Dr. Benizri, the findings do not mean that every older adult should immediately begin walking faster, especially if they are not used to it. However, they reinforce the importance of continuing physical activity at older ages.
“Today we see more people in their 80s who continue going to the gym, running, cycling, lifting weights or walking on a treadmill,” Dr. Benizri said. “This was less common a few decades ago. Today there is greater awareness that even an 80-year-old can continue exercising and maintain good physical fitness. Of course, it should be done in a controlled manner and according to one’s abilities, but it is possible and recommended.”
She said the practical conclusion is not that people should suddenly increase their walking speed. “You do not need to start walking faster if that is not something you are used to, but it is worth increasing the amount of physical activity, walking more and using the car less. We see a clear connection between good, regular physical activity and good cognitive function,” she said.
It is important to note that the study found an association only and does not prove that fast walking prevents cognitive decline. Walking speed may reflect better overall health, higher physical fitness or a slower rate of aging in the body and brain.