A moderate-intensity walking regimen may improve cognitive function in adults with mild vascular cognitive impairment, a small study suggests.
Participants with vascular cognitive impairment who walked three hours per week for six months had improved reaction times and other signs of improved brain function, the researchers report in British Journal of Sports Medicine.
“It is well established that regular aerobic exercise improves cardiovascular health and cerebrovascular health,” the study’s senior author Teresa Liu-Ambrose told Reuters Health.
More specifically, it reduces one’s risk of developing chronic conditions such as hypertension, diabetes, and high cholesterol. "These chronic conditions have a negative impact on the brain - likely through compromised blood flow to the brain,” said a researcher with the Aging, Mobility, and Cognitive Neuroscience Lab at the University of British Columbia in Vancouver, Liu-Ambrose.
The brain is a highly metabolic organ and to keep it healthy, it requires good blood flow to deliver the necessary nutrients and oxygen to its tissues, she added.
It is well established that regular aerobic exercise improves cardiovascular health and cerebrovascular health.
“It is worth noting that in our study, reduced blood pressure (secondary to exercise) was associated with improved cognitive function,” Liu-Ambrose said.
Aerobic exercise may also benefit the brain by increasing growth factors, she said.
Liu-Ambrose and colleagues randomly assigned 38 older adults with mild vascular cognitive impairment (VCI) to one of two groups. One group followed an aerobic training program consisting of three one-hour walking classes each week for six weeks, while the other group continued with their usual care. In addition, both groups were given information about vascular cognitive impairment and tips for eating a healthier diet.
Before the exercise program began and at the end of six weeks, all the participants also had functional MRI brain scans and other tests that measured neural activity and cognitive ability.
People in the aerobic training group had significant improvements in their reaction times on the cognitive tests, and showed changes in their brain activity that made them resemble healthy brains more. The comparison group showed no changes.
Overall, exercise appears to be a promising strategy for promoting cognitive health in older adults, Liu-Ambrose said.
“While more research is needed to better understand how it brings about its benefits and what factors may impact the degree of benefit observed, there is minimal negative consequence of exercising,” she said.
Liu-Ambrose said she does not know if exercise can actually prevent VCI because there have been no studies to determine that. “However, population based studies do suggest that physical activity does reduce the risk of developing VCI. Moreover, as mentioned earlier, aerobic exercise is very effective in reducing vascular risk factors associated with VCI, such as high blood pressure.”
The study was small, and because participants had to be able to walk for up to an hour, it is possible they were physically healthier than average, the authors note. The socializing involved in the walking classes might have also had some effect, they add.
“Given the small sample size, one needs to be cautious about interpreting the results of this pilot study. However, it is encouraging to see that the six-month aerobic exercise program improved certain aspects of cognition and showed changes on functional brain imaging,” said director of the Montefiore Einstein Center for the Aging Brain at Montefiore Medical Center in New York, Dr Joe Verghese.
“The effect of exercise in this, and other studies seems to be on improving executive functions, which are required for planning, thinking and judgment,” Verghese, who was not involved in the study, said.
“The findings, if confirmed in larger studies, may have implications in advising exercise in older patients with vascular risk factors for brain protection,” Verghese said.