Your sleep quality—or lack thereof—might affect your brain down the road, says new research from a team of neurobiologists.
Study: If You Have This Sleep Problem, You May Be More Prone to Memory Loss
Published on May 31, 2025
Getting restful shut-eye every night is something we all want, but sleep disorders such as sleep apnea or narcolepsy can make the quest for quality slumber much more complicated.
Almost 30 million Americans have obstructive sleep apnea, according to 2023 data from the American Academy of Sleep Medicine. If left untreated, sleep apnea can lead to other health concerns, such as stroke, diabetes, or cardiovascular disease.
To further confirm the importance of good sleep, a new study, published this month in the peer-reviewed journal Neurology, found a possible link between the disruptive pattern of sleep apnea and memory loss, as well as dementia risk.
For the study, the neurobiologists included 37 people—the participants, who had an average age of 73 years, did not have any cognitive impairment and did not take any sleep medications. The participants were then put in overnight sleep studies and had advanced brain imaging done.
It was determined that 24 of the participants had obstructive sleep apnea, which is when throat muscles relax and block the airway during sleep…and the lower oxygen levels in their brains appeared to have had a direct impact.
“The study found the brain changes were strongly associated with the severity of drops in oxygen levels during rapid eye movement (REM) sleep,” according to a press release from the American Academy of Neurology.
One of the study’s authors, Dr. Michael Yassa, further explained in a press release: “We may have found a missing piece of the puzzle. Low oxygen during REM sleep seems to harm tiny blood vessels in the brain, and that damage shows up in areas we rely on for memory. This might help explain why even mild sleep apnea can impact brain health long before memory problems show up.” Dr. Yassa is a professor of neurobiology and behavior at the University of California, Irvine.
Specifically, the study discovered higher levels of white matter hyperintensities—spots seen on brain scans that are “thought to reflect damaged white matter tissue”—and those hyperintensities were then linked to “decreased volume as well as reduced thickness” in the hippocampus and entorhinal cortex, both of which are important for memory function.
REM sleep is key because during it “your brain does some of its most important cleanup and memory storage work,” said Destiny E. Berisha, an author of the study and a doctoral researcher in neurobiology and behavior at UC Irvine. “If oxygen levels drop during that time, we may be interrupting critical maintenance for the brain’s memory systems.”
Though the researchers were clear that the study does not necessarily prove that sleep apnea leads to degeneration, it does show a connection.
Ultimately, the findings support “a growing body of evidence linking sleep disorders and dementia,” per the team at UC Irvine.
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