The surprising reason exercise improves symptoms of Alzheimer’s
Though we already know that physical activity is good for us, new research has discovered that it may have even more benefits for those with Alzheimer’s disease.
A team of researchers have identified a potential explanation for why exercise improves brain health.
Dr Kaitlin Casaletto, the study’s senior author and a neurophysiologist at the University of California’s Memory and Ageing Centre, said the study makes the link between exercise and better brain health via inflammation.
“We are starting to show the ‘who of the how’: physical activity related to better cognitive outcomes via reduced brain inflammation, particularly in adults with greater Alzheimer’s disease pathology,” she told OverSixty. “Broadly, our study supports the dynamic
and plastic nature of the brain, even in older adults and even in the context of pathology.”
The researchers monitored the activity of microglia - the brain’s immune cells - in 167 older adults, as well as the levels of activation in brain tissue from deceased patients with Alzheimer’s.
As the brain’s first line of immune defence, the cells activate to remove debris, damaged neurons, and foreign invaders. But, if the cells are too active, they can trigger inflammation, damage neurons, and interrupt signalling in the brain.
This was particularly noticeable in a region of the brain responsible for processing visual information. This area is one of the regions severely impacted by Alzheimer’s disease, resulting in difficulty processing new information and remembering it later.
#JNeurosci | New research from @UCSFmac shows physical activity may improve #Alzheimers by lowering brain inflammation. @kbcasaletto et al. show benefits may come through decreased immune cell activation. https://t.co/ZSgCVfnPCQ pic.twitter.com/oSganHTYHj
— SfN Journals (@SfNJournals) November 22, 2021
Physical activity was also found to have a pronounced effect in reducing inflammation in people with severe Alzheimer’s.
“For instance, our study suggests that individuals at risk for Alzheimer’s related inflammation may particularly benefit from an exercise regimen,” Dr Casaletto said.
But, she said it’s important to understand that exercise “may not work for everyone’s brain health”.
Previous work has made the connection between exercise and reduced risks of neurodegenerative diseases such as Alzheimer’s, but Dr Casaletto said the new study is the first to show the same kinds of results in humans.
“Many studies show that physical activity relates to better brain and cognitive health. Yet we still do not fundamentally understand the mechanisms linking physical activity to cognition in humans,” said Dr Casaletto.
“Ours is the first human data showing that brain inflammation may be a meaningful mechanism.”
The researchers also noted that exercise could be used to identify potential treatments.
“Our team aims to identify biological targets that link known neuroprotective factors like physical activity to the brain,” Dr Casaletto said.
“Ideally, if we can ‘bottle’ these biological mechanisms, they could be therapeutic targets for cognitive ageing and Alzheimer’s disease.”
The study was published in the Journal of Neuroscience.
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