Regular Exercise May Fend Off Alzheimer’s Disease, Researchers Say

Researchers have found an association between fitness and blood flow to areas of the brain where the hallmark tangles and plaques of Alzheimer’s disease (AD) are typically detected. The study, “Cardiorespiratory fitness modifies the relationship between myocardial function and cerebral blood flow in older adults,” was published in the journal NeuroImage.

A growing body of evidence indicates that cardiorespiratory fitness attenuates some age-related cerebral declines. However, little is known about the role that myocardial function plays in this relationship. Brain regions with high resting metabolic rates, such as the default mode network (DMN), may be especially vulnerable to age-related declines in myocardial functions affecting cerebral blood flow (CBF).

“We set out to characterize the relationship between heart function, fitness, and cerebral blood flow, which no other study had explored to date,” study lead author Nathan Johnson, PT, DPT, PhD, of the University of Kentucky College of Health Sciences, said in a news release. “In other words, if you’re in good physical shape, does that improve blood flow to critical areas of the brain? And does that improved blood flow provide some form of protection from dementia?”

Researchers recruited 30 men and women ages 59 to 69 who were assessed for treadmill fitness and had heart ultrasounds. Participants then had brain scans preformed to look for blood flow to certain brain regions.

The results revealed that blood flow to some brain regions was higher in those participants who were more physically fit. According to Johnson, the study findings indicate that regular physical activity at any age may help keep the mind young,

“Can we prove irrefutably that increased fitness will prevent Alzheimer’s disease? Not at this point,” Johnson said. “But this is an important first step toward demonstrating that being physically active improves blood flow to the brain and confers some protection from dementia, and conversely that people who live sedentary lifestyles, especially those who are genetically predisposed to Alzheimer’s, might be more susceptible.”

People who exercise regularly usually have reduced arterial stiffness. As such, the researchers believe that regular exercise maintains the integrity of the “pipes” that carry blood to the brain.

“In the mid-late 20th century, much of the research into dementias like Alzheimer’s focused on vascular contributions to disease, but the discovery of amyloid plaques and tangles took prevailing research in a different direction” Johnson said. “Research like this heralds a return to the exploration of the ways the vascular system contributes to the disease process.”