Physical Activity Can Ward Off Dementia In Elderly People. New Study Explains How

The researchers tracked the late-life physical activity of elderly participants as part of the study.

Representational images (Source: Getty)

New Delhi: The brains of elderly people who regularly exercise and stay active have more of a class of proteins that enhances the connections between neurons and helps maintain a healthy cognition, according to a new study.

The study, conducted by researchers from the University of California, San Francisco in the US, was published in the January 7 issue of Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

How Physical Activity Protects The Brain

The study found the protective impact even in people whose brains at autopsy revealed toxic proteins associated with Alzheimer's and other neurodegenerative diseases. Physical exercise protects the neuronal junctions and can ward off dementia, according to the study.

In a statement issued by the University of California, San Francisco, Kaitlin Casaletto, the lead author of the study, said the work is the first that uses human data to show that synaptic protein regulation is related to physical activity and may drive beneficial cognitive outcomes. 

Earlier, scientists demonstrated the beneficial effects of physical activity on cognition in mice. However, it is harder to demonstrate in humans.

Casaletto worked with Professor William Honer from the University of British Columbia to leverage data from the Memory and Aging Project at Rush University in Chicago. 

The researchers tracked the late-life physical activity of elderly participants as part of the study. These participants have pledged their brains for research after death.

Casaletto said that maintaining the integrity of the connections between neurons may be important for warding off dementia. 

This is because the synapse, or the neuronal junction, is the site where cognition happens. According to Britannica, cognition includes all conscious and unconscious processes by which knowledge is accumulated, such as perceiving, recognizing, conceiving, and reasoning.

Casaletto said that physical activity, which is a readily available tool, may help boost this synaptic functioning.

More Proteins Lead To Better Nerve Signals

Elderly people who remained active had higher levels of proteins that facilitate the exchange of information between neurons, the study found. These results conformed to a previous study by Honer, which found that people who had more of these proteins in their brains when they died were better able to maintain their cognition late in life, the study said.

The researchers found that the effects ranged beyond the hippocampus, the brain's seat of memory. As a result, the effects encompass other brain regions associated with cognitive function, the study said.

Honer said that it may be possible that physical activity exerts a global sustaining effect, supporting and stimulating healthy function of proteins. These proteins facilitate synaptic transmission throughout the brain, he said.

Synapses Protect Brains That Show Signs Of Dementia

Amyloid and tau are toxic proteins that are the hallmarks of Alzheimer's disease pathology. These are accumulated in the brains of most older adults.

According to scientists, synapses and neutrons fall apart because amyloid accumulates first, followed by tau.

Synaptic integrity, whether measured in the spinal fluid of living adults or the brain tissue of autopsied adults, appeared to dampen the relationship between amyloid and tau, and between tau and neurodegeneration, according to a previous study conducted by Casaletto.

She said that the cascade of neurotoxicity that leads to Alzheimer's appears to be attenuated in older adults with higher levels of the proteins associated with synaptic integrity.

She said the two studies show the potential importance of maintaining synaptic health to support the brain against Alzheimer's disease.