A study led by scientists at Rutgers University-New Brunswick has found that exercise may directly enhance brain function by improving how the brain responds to insulin. The findings, published in Aging Cell, suggest that targeting insulin action in the brain could help prevent or slow the progression of dementia.
The Role of Insulin in Brain Health
The study, conducted in collaboration with the National Institute on Aging, focused on extracellular vesicles—tiny particles released by the brain that transport proteins between cells. Researchers specifically examined vesicles carrying proteins related to insulin sensitivity, including one known as Akt.
Insulin plays a crucial role in brain function, influencing memory, cognitive processing, and synaptic activity—the process by which brain cells communicate. Impaired insulin sensitivity has been linked to cognitive decline and conditions such as Alzheimer’s disease.
How Exercise Impacts Insulin Sensitivity in the Brain
To investigate the impact of exercise, researchers monitored a group of 21 participants, averaging 60 years of age, all of whom had prediabetes. Over a two-week period, participants completed 12 supervised exercise sessions lasting 60 minutes each, ranging from moderate to high intensity. Blood samples were collected before and after exercise, as well as before and after the participants consumed a glucose drink.
Results showed a significant increase in neuronal vesicles carrying insulin-related proteins after each exercise session. Lead author Steven Malin, an associate professor in the Department of Kinesiology and Health at Rutgers, noted that this was the first study to demonstrate the effect of exercise on insulin signaling through neuronal extracellular vesicles.
“We showed for the first time that exercise impacts insulin signaling from neuronal extracellular vesicles in relation to clinical improvements in blood sugar,” Malin said. “And we use these neuronal extracellular vesicles as an indicator of brain insulin sensitivity.”
Future Research and Potential Therapies
The study builds on previous research linking high blood sugar to reduced cognitive function, but the exact mechanisms behind exercise’s cognitive benefits have remained unclear. These new findings suggest that physical activity helps improve insulin sensitivity in the brain, potentially offering a new therapeutic target for dementia prevention.
Malin and his colleagues are now conducting further research to determine whether a single bout of exercise can enhance the effects of intranasal insulin—a treatment method that delivers insulin directly to the brain—on cognitive health in aging adults with obesity. They also plan to conduct long-term studies to assess whether ongoing exercise training can improve brain insulin sensitivity and cognition in older adults.
The findings add to growing evidence that it may be a key factor in maintaining cognitive health, particularly for individuals at risk of insulin resistance-related conditions such as diabetes and dementia.
Reference: Steven K. Malin, Daniel J. Battillo, Michal S. Beeri, Maja Mustapic, Francheska Delgado‐Peraza, Dimitrios Kapogiannis. Two weeks of exercise alters neuronal extracellular vesicle insulin signaling proteins and pro‐BDNF in older adults with prediabetes. Aging Cell, 2024.
