In a new study, researchers found that high-risk subjects who took up aerobic exercise improved brain glucose metabolism and executive functioning, the higher-order thinking abilities such as planning and mental flexibility.
These improvements occurred alongside increased cardiorespiratory fitness.
“This research shows that a lifestyle behavior — regular aerobic exercise — can potentially enhance brain and cognitive functions that are particularly sensitive to the disease. The findings are especially relevant to individuals who are at a higher risk due to family history or genetic predisposition,” said lead investigator Ozioma C. Okonkwo, Ph.D., of the Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health.
The results of the study are published in the journal Brain Plasticity.
Current Alzheimer’s drugs have limited therapeutic capacity. As the disease is projected to rise dramatically in the coming decades, there is a critical need to provide people with easy strategies that can decrease the risk of developing the condition or slow its progression.
“This study is a significant step toward developing an exercise prescription that protects the brain against AD, even among people who were previously sedentary,” said Okonkwo.
The study looked at 23 cognitively normal, relatively young older adults with a family history or genetic risk for AD. All patients had a sedentary lifestyle. The participants underwent multiple assessments, including cardiorespiratory fitness testing, measurement of daily physical activity, brain glucose metabolism imaging (a measure of neuronal health), and cognitive function tests.
Half of the participants were randomly assigned to receive information about maintaining an active lifestyle but no further intervention. The other half participated in a moderate-intensity treadmill training program with a personal trainer, three times per week for 26 weeks.
Compared to participants who kept their usual level of physical activity, those assigned to the active training program improved their cardiorespiratory fitness, spent less time sedentary after the training program ended, and performed better on cognitive tests of executive functioning (but not episodic memory).
Executive function, an aspect of cognition that is known to decline with the progression of AD, includes the mental processes that allow individuals to plan, focus attention, remember instructions and juggle multiple tasks successfully. The participants’ improved cardiorespiratory fitness was associated with increased brain glucose metabolism in the posterior cingulate cortex, an area of the brain linked to AD.
The lead author on the study, Max Gaitán, M.Ed., of the Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, remarked that “an important next step would be to conduct a larger, more definitive, study.”
“If these findings are replicated, they would have a tremendous impact on quality of later life, providing individuals with more years of independent living, active engagement with loved ones, and building memories.”