Your brain may age at a different rate than the rest of your body, according to a new study published on Thursday, March 19, 2026, in JAMA Network Open. The research suggests that signs of this process can be detected during sleep, offering a potential new way to assess cognitive health.
Researchers found that patterns of brain activity during sleep, measured through specific tests, are associated with accelerated brain aging. This phenomenon may increase the risk of developing dementia over time, according to the scientists. Understanding how brain aging differs from chronological age is a growing area of research, as early detection could lead to preventative strategies.
The study, conducted by researchers at the University of California, San Francisco (UCSF), gathered data from 7,105 individuals between the ages of 54 and 94, drawing from five long-term studies. Participants were followed for up to 17 years.
During this period, scientists analyzed detailed records of brain activity during sleep, obtained through electroencephalograms (EEGs). This data allowed them to assess the complex electrical signals produced by the brain while individuals slept.
Using artificial intelligence, the researchers estimated what they termed each participant’s “brain age” – an indicator based on the patterns of brain function during sleep. This approach allowed for a more nuanced assessment of brain health than traditional methods.
The results showed that individuals whose brains appeared “older” than their actual age had a higher risk of developing dementia. Generally, the greater the difference between chronological age and estimated brain age, the higher the observed risk over the course of the study. A 10-year difference in brain age corresponded to nearly a 40% increase in the risk of neurodegenerative diseases.
According to Yue Leng, professor of psychiatry at UCSF and senior author of the study: “The findings suggest that sleep problems may be associated with accelerated brain aging. Improving sleep may be an important pathway for protecting brain health over time.”
What Does Brain Aging Mean?
Brain aging isn’t solely determined by a person’s chronological age. It’s as well linked to changes in the brain’s structure and function, which can occur more rapidly in some individuals. This research highlights the importance of understanding these individual differences in cognitive decline.
In the study, this aging process was identified by analyzing patterns of electrical activity in the brain during sleep – a method that provides an indirect view of brain function.
This finding reinforces the idea that brain changes can begin years before more obvious symptoms emerge, such as memory loss or difficulty with reasoning. Identifying these early changes could be crucial for preventative care.
The study does not prove that sleep, on its own, causes brain aging. However, it demonstrates that sleep patterns can serve as an important indicator of brain health.
In practice, In other words that changes in sleep – particularly those detected through more detailed tests – may help identify individuals at higher risk of cognitive decline in the future.
Researchers emphasize that brain aging can occur silently for years. Identifying early signs – such as changes in brain patterns during sleep – may be essential for prevention.
While further research is needed, the results reinforce the importance of viewing sleep not just as rest, but as a reflection of brain health throughout life.
