A GROUNDBREAKING study led by scientists based in the USA has revealed that exercise could directly improve brain function by enhancing how the brain responds to insulin. This research suggests that physical activity may play a key role in reducing the risk of dementia.
The study focused on the effects of exercise on insulin action in the brain. “This work is important because it suggests that exercise may improve cognition and memory by boosting the brain’s ability to respond to insulin,” the authors explained.
In collaboration with the National Institutes of Health’s National Institute on Aging, the research team examined neuronal extracellular vesicles – tiny, specialised cells released by the brain. These vesicles have been recognised in recent years as crucial players in transporting proteins, including those related to insulin sensitivity.
Insulin sensitivity refers to how effectively the body responds to insulin, a hormone that regulates blood sugar levels. High insulin sensitivity helps the body utilise blood glucose more efficiently, particularly in muscles, which lowers blood sugar. In contrast, insulin resistance – a hallmark of conditions like Type 2 diabetes – can impair brain function, contributing to cognitive decline.
For this study, the researchers tested 21 volunteers, aged around 60, who had prediabetes. Over two weeks, participants took part in 12 supervised exercise sessions, engaging in moderate to high-intensity activity. Blood samples taken before and after the exercise revealed a significant increase in the number of neuronal vesicles carrying proteins related to insulin sensitivity, with Akt – a key protein – showing notable increases.
The team highlighted the importance of these findings: “We demonstrated for the first time that exercise impacts insulin signalling in the brain and improves blood sugar control.”
The results suggest that exercise may not only benefit physical health but also protect against cognitive decline by enhancing brain insulin sensitivity, a crucial factor in memory, learning, and overall brain function. With prediabetes already linked to a higher risk of dementia, this research paves the way for future therapies targeting brain insulin action to help prevent diseases like Alzheimer’s.
Victoria Antoniou, EMJ
Reference
Malin SK et al. Two weeks of exercise alters neuronal extracellular vesicle insulin signaling proteins and pro-BDNF in older adults with prediabetes. Aging Cell. 2025;24(1):e14369.
