Walking every day could help keep dementia at bay, according to a study published in the January 2018 issue of the Journal of Alzheimer’s Disease.
WHY 4,000 STEPS
The researchers recruited 29 adults over the age of 60 to explore how physical activity affected the thickness of brain structures. Participants were divided into two groups: one group that walked more than 4,000 steps per day and another group that logged fewer than 4,000 steps (as measured by accelerometers).
At the end of the two-year study, the group that walked more than 4,000 steps had thicker medial temporal lobes (the sub-regions of the brain important for cognition) and better cognitive functioning than those who walked less. Thickness of brain structures can be an early marker of brain health, according to lead researcher Prabha Siddarth, PhD, research statistician at the Semel Institute of Neuroscience and Human Behavior at UCLA.
“We found that older adults who walked more than 4,000 steps daily had significantly superior performance in attention and information-processing speed as well as executive functioning, a set of mental skills that allows you to make plans and achieve goals,” explains Siddarth.
While the reasons for the connections between physical activity and brain health remain unclear, Siddarth offers two possible explanations: Physical activity can increase brain-derived neurotrophic factor (BDNF), which is associated with cognitive improvements; physical activity also increases the brain’s ability to change as you age, referred to as plasticity.
“Based on the findings of the study, we would suggest that adults over 60 years of age with memory complaints walk over 4,000 steps per day both for brain health and improving cognition,” he says.
THE BENEFITS OF PHYSICAL ACTIVITY
The study published in the Journal of Alzheimer’s Disease was not the first to explore the link between physical activity and brain health.
A meta-analysis published in Mayo Clinic Proceedings reviewed 29 studies and found links between regular physical activity and decreased cognitive decline, noting improvements in memory, attention and processing speed.
More recently, a 2017 study found that adults between the ages of 60–85 who rode an exercise bike for 30 minutes three times per week over 12 weeks had better brain metabolism than their less active peers. In particular, exercise appeared to prevent an increase in choline, a metabolite often found at higher levels in those with Alzheimer’s disease.
Heather Snyder, PhD, senior director of medical and scientific operations for the Alzheimer’s Association, believes earlier interventions, including physical activity, are essential to protecting against cognitive decline.
“We want to do what we can to change the trajectory of [Alzheimer’s disease] or maybe even prevent it from happening at all,” Snyder says.
The Alzheimer’s Association is currently recruiting 2,500 participants to the U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk (U.S. POINTER), a two-year study focused on the effects of interventions like exercise could help prevent cognitive decline.
“Right now, there is no perfect recipe of behaviors that may delay or prevent dementia onset,” says Snyder. “Until we figure out that formula, the best advice is to get up and move; it’s good for your body and it’s good for your brain.”