It gets even better. A new study finds exercise boosts levels of a protein known to strengthen communication between brain cells via synapses, which may be a key factor in keeping dementia at bay.
The protective effect was even found in active older people whose brains showed signs of plaques, tangles and other hallmarks of Alzheimer’s and other cognitive diseases.
“Synapses are the critical communicating junctions between nerve cells and are really where the magic happens when it comes to cognition,” said study author Kaitlin Casaletto, an assistant professor of neurology in the Memory and Aging Center at the University of California San Francisco, in an email.
“All of our thinking and memory occurs as a result of these synaptic communications,” she added.
Prior studies have shown that physical activity can reduce risk of dementia by 30% to 80%, “yet we do not understand how this happens at a biological level in humans,” Casaletto explained.
“We have described, for the first time in humans, that synaptic functioning may be a pathway through which physical activity promotes brain health,” she said, adding that the study could only show an association, not necessarily cause and effect.
Still, Casaletto added, “I think these findings begin to support the dynamic nature of the brain in response to our activities, and the capacity of the elderly brain to mount healthy responses to activity even into the oldest ages.”
Protein regulation is key
A well-functioning brain keeps electrical signals moving smoothly through synapses from neuron to neuron and to other cells in the body. To do so, the brain needs to constantly replace worn-out proteins in those synapses, while also making sure they are properly balanced and regulated.
“There are many proteins present at the synapse that help facilitate different aspects of the cell-to-cell communication. Those proteins need to be in balance with one another in order for the synapse to function optimally,” Casaletto wrote.
It’s all part of how the brain remodels its neural circuits, keeping them healthy.
Studies in mice have long shown the protective effect of exercise on the brain once autopsied, but establishing that link in humans has been difficult,
As part of that project, the late-life physical activity of elderly participants was also tracked. The findings showed people who moved more had more protective proteins.
“The more physical activity, the higher the synaptic protein levels in brain tissue. This suggests that every movement counts when it comes to brain health,” Casaletto said.
“We recommend aiming for 150 min/week of physical activity. Prior studies have shown that even walking relates to reduced risk of cognitive decline!,” she added via email.
And it appears to work independently of whether a person already has markers for Alzheimer’s and other dementia, she added.
“Several prior studies consistently show … higher levels of these same synaptic proteins in brain tissue associate with better cognitive performance, independent of plaques and tangles,” she wrote.
“These data reinforce the importance of incorporating regular physical activity into our everyday lives — no matter how young or old we are,” said Heather Snyder, vice president of medical and scientific relations for the Alzheimer’s Association, which partially funded the study.
“It’s important to find an exercise you enjoy so it can be sustainable in…