THE ESSENTIAL
- Insulin, essential for memory and neuronal connections, becomes less effective in prediabetes or diabetes, increasing the risk of dementia. However, physical exercise could improve brain function by increasing the brain’s sensitivity to insulin.
- The study found that after 12 exercise sessions over two weeks, neuronal vesicles carrying insulin-related proteins, like Akt, increased.
- These results pave the way for targeted therapies to prevent cognitive decline.
Insulin, a blood glucose regulating hormone, is increasingly recognized for its role in cognitive functions. It promotes cerebral blood flow and neuronal functioning, essential for memory, the speed of information processing and interactions between nerve cells. However, in cases of prediabetes or diabetes, the brain can become resistant to insulin, leading to cognitive disruptions and an increased risk of dementia, including Alzheimer’s disease.
Physical exercise could thus play a key role in improving brain function by acting directly on insulin sensitivity in the brain. This is what a team of researchers from Rutgers University-New Brunswick, in the United States, suggests in a study published in the journal Aging Cell.
The impact of exercise on insulin in the brain
Their work reveals that specialized cells, called neuronal extracellular vesicles, could be the key to understanding this link. “If insulin is insufficient in the brain, nerve cells can become dysfunctional and lose their ability to communicate properly, which can contribute to memory and learning problems”explain the scientists in a press release.
To explore this phenomenon, researchers conducted a two-week experiment on 21 prediabetic volunteers, with an average age of 60 years. These participants completed 12, 60-minute, moderate-to-high-intensity supervised exercise sessions. Before and after these sessions, blood samples were taken, revealing an increase in neuronal vesicles carrying key proteins linked to insulin sensitivity, including Akt.
-“We demonstrated for the first time that exercise influences insulin signaling via neuronal extracellular vesicles linked to clinical improvements in blood glucose”emphasize the researchers. This increased sensitivity could partly explain why exercise improves cognition.
Towards new therapies against dementia?
The results open perspectives on the development of therapies targeting the action of insulin in the brain to prevent or slow the progression of dementia. A study currently underway is examining whether a single exercise session can improve the effectiveness of insulin administered intranasally in aging adults suffering from obesity.
The authors conclude: “Targeting brain insulin could be a promising strategy to preserve cognitive health.” In the meantime, regular exercise remains a key recommendation to protect both the body and the mind.
