Nature Medicine published Fernanda De Felice’s study on irisin and its effect on and prevention of Alzheimer’s disease on Jan. 7—and since then, her findings have garnered international attention. 

An adjunct professor at Queen’s within the Department of Psychiatry, De Felice has been at the university for two years. However, her collaboration history with the school’s Centre for Neuroscience Studies (CNS) stretches as far back as a decade. 

After a 2012 Harvard study identified irisin—a hormone produced by the muscle following exercise—De Felice narrowed her research to study the hormone. 

“Because of my previous studies with other hormones in the brain, I decided to study irisin in the context of Alzheimer’s disease—this research started more than six years ago in my lab,” De Felice told The Journal in an interview.

When De Felice and her colleagues started their research, it wasn’t known whether irisin would be present in the brain or not. 

“The first experiment was to see: ‘Okay, what is going on in the brains of Alzheimer’s patients regarding this molecule, irisin,’” De Felice recalled. 

They turned to the hippocampus—the brain region known for its role in learning and memory—and looked at levels of irisin in both people of a control group and people with Alzheimer’s.

Levels of irisin were decreased in the hippocampi of the Alzheimer’s patients. The same results occurred in testing the Cerebrospinal Fluid of both groups.

De Felice and her colleagues concluded that there might be a link between reduced irisin and Alzheimer’s. The resulting published study names co-authors from the University of Rio de Janeiro, where De Felice also holds a position as an associate professor.

Her research moved onto experiments in animal models—mice could be trained so their performance and memory of training can be evaluated. When treated with irisin, animal models of Alzheimer’s disease showed improved memory and decreased cognitive impairment. 

To increase levels of irisin in the brain, mice were subject to an exercise protocol—they had to swim in a small pool five times a week for five weeks. Researchers isolated irisin as the key to cognitive improvement by observing that when irisin was blocked in mice, even with exercise, their memory performance didn’t improve. 

“This indicates that this molecule is actually very important, it is a key molecule stimulated by exercise that mediates the beneficial effects on memory,” De Felice said. 

Although there’s currently no cure for Alzheimer’s disease, this discovery is a significant contribution to potential drug treatments to treat it. For those already affected by the disease and unable to exercise due to age-related health problems, identifying the effects of irisin on the brain presents the possibility for potential treatment options.

However, for those capable of regular physical activity, naturally occurring irisin through exercise could be a preventative measure.

Alzheimer’s can develop decades before real symptoms show and before a person has reached an age vulnerable to memory deficits, according to De Felice.

“Even when you’re 40, 30, some problems start to occur and it progresses silently,” De Felice said. “I think that what this study [shows] is that we have some natural ways to preventthe brain from getting the disease later in life.”

De Felice stresses that a healthy lifestyle, not irisin alone, is crucial to maintaining a healthy brain. 

“It’s all very connected,” she said. “We can identify how the brain gets sick by finding the connection between the periphery and the brain, but then we can also try to find natural ways to protect the brain if we better understand [that] connection.”

De Felice has received grants from the Weston Brain Institute and the Alzheimer’s Society to continue her research into irisin and its relationship with Alzheimer’s.

“[To students] I would say hit the gym, don’t forget to do your exercise.”