Increasingly widespread around the world, madness negatively affect the lives of millions of people. people and their families. At the time of diagnosis, the process appears to be irreversible. However, new research from the JAMA Network Open identifies muscle mass as a modifiable factor that could be used to reduce the risk of developing the disease before it’s too late.
The work highlights the importance of muscle mass as an independent factor linked to rapid cognitive decline. “Low muscle strength has recently been associated with a higher risk of dementia, but little is known about a possible link between muscle mass and cognition,” says lead author Stéphanie Chevalier, a scientist with the Program on metabolic disorders and their complications at the McGill University Health Center Research Institute. “With this study, we show for the first time that the presence of low muscle mass is significantly associated with faster cognitive decline and that this association is independent of muscle strength and level of physical activity, among other factors. .
“These results are important because muscle mass is a modifiable factor, which means we can do something about it. Exercise – especially resistance exercise – and a good diet with enough protein can help maintain muscle mass over the years,” adds Chevalier, who is also an associate professor at McGill University’s School of Human Nutrition.
The researchers conducted the study using data from the Canadian Longitudinal Study on Aging (CLSA), which has a rich body composition data set and several cognitive tests performed in person, at intervals of three years, on a cohort of 30,000 people. The research team asked whether having low muscle mass predicts later cognitive decline in three domains – memory, executive function and psychomotor speed – in adults aged 65 and older.
“We found that low muscle mass was associated with greater decline in executive cognitive function over three years, compared to normal muscle mass, but not with loss of memory or psychomotor function,” explains the first author. Anne-Julie Tessier, a doctoral student with Stéphanie Chevalier at the time of this study, who is now a postdoctoral fellow at Harvard University. “Executive functions are important in our daily activities and behaviors because they help us maintain our attention, organize our thoughts, and make decisions.”
In addition to their role in strength and physical functioning, muscles are the storehouse of proteins that serve several important bodily processes. Muscles also secrete molecules that can “talk” to the brain. It is also known that exercising and building muscle mass, by bringing more blood flow to the brain, can promote executive functioning.
“Our results show that measuring low muscle mass can help identify people at higher risk for cognitive decline. We should be measuring muscle more broadly, in clinics, not just in research studies,” says Chevalier, “Further work should determine whether maintaining or gaining muscle attenuates cognitive decline with age and, if there is a causal link, what the mechanisms are.”