Exercise and the Brain

Scientists at UC San Francisco have found that, when elderly people stay active, their brains have more of a class of proteins that enhances the connections between neurons to maintain healthy cognition. In other words, the benefits of exercise for older adults include brain health, learning, and memory.

"It may be that physical activity exerts a global sustaining effect, supporting and stimulating healthy function of proteins that facilitate synaptic transmission throughout the brain," says research leader William Honer in a press release issued by UC San Francisco. Protection from toxic proteins, that cause synapses and neurons to fall apart, promotes synaptic integrity and reduces the risk of neurodegeneration.

A research paper is published in Alzheimer's & Dementia. It analyzes data from the Memory and Aging Project at Rush University. That project tracked the late-life physical activity of elderly participants, who also agreed to donate their brains when they died.

The UC San Francisco scientists found that active elderly people had higher levels of proteins that facilitate the exchange of information between neurons. Surprisingly, these effects ranged beyond the hippocampus, the brain's seat of memory. They encompassed other brain regions associated with cognitive function. Earlier findings indicated that people who had more of these proteins in their brains when they died were better able to maintain their cognition late in life.

"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 researcher Kaitlin Casaletto. In the paper, the researchers suggest “that [physical activity] may help build synaptic health, even at late ages … but that this is a potentially plastic process that may need to be sustained over time.” According to the researchers, this approach to cognitive functioning and resilience is “of high relevance in our aging population.”

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

I may have mentioned one or two times that I don’t enjoy physical activity too much. I very much prefer brainy activity. But I am not getting any younger. And I guess my brain is not as sharp as it used to be.

I can see that physical activity helps my brain stay sharp enough. So yes, I force myself to do regular exercise. And so should you.

"In older adults with higher levels of the proteins associated with synaptic integrity, this cascade of neurotoxicity that leads to Alzheimer's disease appears to be attenuated," concludes Casaletto. "Taken together, these two studies show the potential importance of maintaining synaptic health to support the brain against Alzheimer's disease."