WEDNESDAY, Dec. 27, 2017 (HealthDay News) -- With New Year's Day fast approaching, one small, new study suggests that seniors interested in preserving their brain health might want to add walking to the top of their resolution list.
Why? A team of investigators from University of California, Los Angeles (UCLA) found that adults over the age of 60 who are already struggling with memory issues are better able to focus and process information if they walk more than 4,000 steps a day (roughly 2 miles).
"We looked at how physical activity affects thickness of brain structures and also cognitive [thinking] performance of adults over the age of 60," explained study author Prabha Siddarth.
Siddarth noted that brain thickness is considered to be "an early and sensitive marker of brain health."
The study revealed that those who walked more than 4,000 steps each day had thicker areas of the brain known to be critical to thought processing.
What's more, such avid walkers demonstrated "better cognitive functioning" than those who walked 4,000 steps or less, she said.
Siddarth is a biostatistician in the department of psychiatry and biobehavioral sciences with the Semel Institute for Neuroscience and Human Behavior and Longevity Center at UCLA.
To explore the potential mental health benefits of walking, the team focused on 26 men and women between the ages of 61 and 88. Nearly 70 percent were women.
While none suffered from dementia, all complained about memory issues.
For one week, all were outfitted with an accelerometer, to track activity patterns.
Participants were then divided into two groups: those who walked more than 4,000 steps per day and those who walked less. (The less active group was older, at an average age of 77, compared with the more active group, at an average age of 68.)
In addition, MRI brain scans were conducted and each participant underwent a battery of mental health tests to assess memory skills, learning skills, verbal skills, attention and information-processing abilities, decision-making function and the ability to execute a task.
The investigators found that those who walked in excess of 4,000 steps per day had thicker brain measurements in the area of the hippocampus and surrounding regions. Collectively, greater brain thickness in such regions has previously been linked to better thinking and memory.
In terms of information-processing speed, the ability to pay attention, and the ability to make plans and meet goals, those in the 4,000-plus group also demonstrated a "substantial" leg up over the less mobile group, said Siddarth, though the degree of the advantage varied.
But she said it remains unclear whether walking even more -- above 4,000 steps -- might further improve mental health. "This is something we are working on to see if more exercise leads to more improvement, and also to see if this is paralleled in brain thickness measures," Siddarth said.
The study authors noted that the finding is an association, rather than proof that daily walking actually protects the brain.
This latter point was seconded by Adam Woods, assistant director of the University of Florida's Center for Cognitive Aging and Memory (CAM), in Gainesville.
"I think caution is warranted when interpreting [these] results as causal," Woods said. He added that the findings stem from just a small group of people whose activity patterns were only correlated with brain function, rather than shown to affect it.
Woods also pointed out that "neither of these findings is novel. Prior work has shown that persons with higher physical activity have correlated differences in brain volume and cognitive performance," he said.
Woods, who also serves as director of the CAM Neurophysiology and Neuromodulation Research Core at the McKnight Brain Institute, said that "these results suffer from the classic 'chicken or the egg' conundrum. Did higher walking lead to increased hippocampal volume and better cognition in these people, or did better cognition and larger hippocampal volume drive their increased physical activity?"
So for now, he concluded, the finding in "no way speaks to whether physical activity could improve cognition and brain volume."
The findings were published online recently in the Journal of Alzheimer's Disease.
There's more on seniors and the benefits of exercise at the U.S. National Institute on Aging.