The results of research from the Harvard Aging Brain Study at Massachusetts General Hospital show high levels of daily physical activity may protect against cognitive decline and brain tissue loss from Alzheimer’s disease. Researchers also noted lowering vascular risk factors may offer additional protection and delay progression of the life-altering disease.
The good news is you don’t have to go to the gym to see the benefits because researchers used an ordinary pedometer to measure the number of steps a person walked to rate their level of activity.
Scientists have learned the physiological processes that lead to full-blown Alzheimer’s disease start well before, even decades in some instances, the clinical symptoms are seen. This happens with the early accumulation of b-amyloid protein in the brain.
The report findings show physical activity could preserve gray matter and reduce cortical thinning as a result of b-amyloid buildup in regions of the brain that have been linked to memory loss and neurodegeneration from Alzheimer’s.
Researchers say the Harvard Aging Brain Study is one of the first to show the protective effects of physical activity and vascular risk management prior to the onset of Alzheimer’s. This preclinical stage offers an opportunity to head off potential neurological impairment that is sure to come without some sort of intervention.
"One of the most striking findings from our study was that greater physical activity not only appeared to have positive effects on slowing cognitive decline, but also on slowing the rate of brain tissue loss over time in normal people who had high levels of amyloid plaque in the brain," says Jasmeer Chhatwal, MD, Ph.D. of the MGH Department of Neurology. "Because there are currently no disease-modifying therapies for Alzheimer's disease, there is a critical need to identify potential risk-altering factors that might delay progression of the disease."
The report published in the Journal of the American Medical Association Neurology detailed how the MGH study assessed the physical activity of 182 older adults who were judged to be at high risk of cognitive decline, including those with elevated b-amyloid. They tracked the number of steps they walked daily.
"Beneficial effects were seen at even modest levels of physical activity, but were most prominent at around 8,900 steps, which is only slightly less than the 10,000 many of us strive to achieve daily," said Reisa Sperling, MD.
Sperling also said approaches designed to target vascular risk factors such as weight, smoking, blood pressure and others added more benefits along with exercise.
MGH is continuing to look into ways physical activity and lifestyle changes can help slow the development of Alzheimer’s disease.
"Beta amyloid and tau protein build-up certainly set the stage for cognitive impairment in later age, but we shouldn't forget that there are steps we can take now to reduce the risk going forward—even in people with build-up of these proteins," says Chhatwal. "Alzheimer's disease and the emergence of cognitive decline is multifactorial and demands a multifactorial approach if we hope to change its trajectory."