A new study led by scientists at Rutgers University–New Brunswick has found that exercise might improve brain health by helping brain cells respond better to insulin.
This discovery could lead to new treatments to help prevent or slow down dementia. The study was published in the journal Aging Cell, which focuses on the science of aging.
The researchers believe this is an important step in understanding how exercise supports memory and thinking. “We think exercise helps the brain work better by improving how insulin acts in the brain,” said Steven Malin, the lead author and an associate professor at Rutgers.
The research was done in partnership with the National Institute on Aging. The team focused on tiny particles called extracellular vesicles. These particles are released by brain cells and help carry important proteins between cells. Although once thought to be useless, these vesicles are now seen as important messengers in the body.
In this study, the researchers looked at specific vesicles that carry proteins linked to insulin sensitivity—especially a protein called Akt. Insulin sensitivity refers to how well the body responds to insulin, the hormone that controls blood sugar levels.
In healthy people, insulin helps move sugar from the blood into cells like muscles and the brain. But in people with insulin resistance, which is common in diabetes, the brain doesn’t respond to insulin as well. This can hurt memory and thinking.
To study this, the researchers recruited 21 participants, all around 60 years old, who had prediabetes. Over two weeks, these individuals completed 12 supervised exercise sessions, each lasting 60 minutes at a moderate to high intensity. The participants also drank a sugary drink before and after their exercise sessions.
Blood samples were taken before and after the training. The results showed that the number of brain-derived vesicles carrying insulin-related proteins increased after exercise. The protein Akt was especially noticeable. This suggests that exercise boosts insulin-related signals from the brain, which may improve brain function.
“We showed for the first time that exercise affects how brain cells respond to insulin, and that this is connected to better blood sugar control,” said Malin. He added that these vesicles can serve as a sign of how well the brain is responding to insulin.
Insulin doesn’t just manage blood sugar. It’s also important for thinking, learning, and memory. People with prediabetes have a higher risk of not getting enough insulin to their brain, increasing their risk for dementia and diseases like Alzheimer’s.
If brain cells don’t get enough insulin, they can become unhealthy and stop communicating properly. Malin compared this to playing a game of telephone, where the message gets lost as communication breaks down.
Although it’s long been believed that exercise helps with memory, researchers haven’t fully understood why. This study points to insulin as a key part of the puzzle. High blood sugar has been shown to weaken the brain’s ability to learn and remember things, so insulin may help by keeping blood sugar in check and supporting healthy brain function.
Malin and his team now plan to explore whether just one session of exercise can improve how well insulin works in the brain. They will test this using brain blood flow and the same vesicles. In the future, they hope to do longer studies to see if regular exercise improves insulin sensitivity in the brain and protects memory in older adults.
If you care about Alzheimer’s disease, please read studies about Scientists find a new way to treat Alzheimer’s disease and findings of Fluctuating cholesterol and triglyceride levels are linked to Alzheimer’s disease.
For more information about Alzheimer’s disease, please read studies about Scientists find root cause of tau tangles in Alzheimer’s disease and findings of new treatment for early-onset Alzheimer’s disease.
The study is published in Aging Cell.
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