The Brain Protecting Power of Exercise.

• Position: NEUROLOGY

When elderly people stay active, their brains have more of a class of proteins that enhances the connections among neurons to maintain healthy cognition, a study appearing in Alzheimer's & Dementia: The Journal of the Alzheimer's Association has found.

This protective impact was uncovered even in people whose brains at autopsy were riddled with toxic proteins associated with Alzheimer's and other neurodegenerative diseases.

"Our work is the first that uses human data to show that synaptic protein regulation is related to physical activity and may drive the beneficial cognitive outcomes we see," says lead author Kaitlin Casaletto, assistant professor of neurology at the University of California, San Francisco.

The beneficial effects of physical activity on cognition have been shown in mice but have been much harder to demonstrate in people.

Casaletto, a neuropsychologist and member of the UCSF Institute for Neurosciences, worked with William Honer, professor of psychiatry at the University of British Columbia and senior author of the study, to leverage data from the Memory and Aging Project at Rush University in Chicago. That project tracked the late-life physical activity of elderly participants, who also agreed to donate their brains when they died.

"Maintaining the integrity of these connections among neurons may be vital to fending off dementia, since the synapse is really the site where cognition happens," Casaletto says. "Physical activity--a readily available tool--may help boost this synaptic functioning."

Honer and Casaletto found that elderly people who remained active had higher levels of proteins that facilitate the exchange of information among neurons. This result dovetailed with Honer's...