Bad Sleep Linked To Accelerated Brain Aging

FRIDAY, Oct. 3, 2025 (HealthDay News) — Rotten sleep might accelerate the aging of a person’s brain, partly by increasing inflammation, a new study says.

People’s brains aged faster as they scored worse on a five-point scale of sleep quality, researchers reported Sept. 30 in the journal eBioMedicine.

“The gap between brain age and chronological age widened by about six months for every one-point decrease in healthy sleep score,” said senior investigator Abigail Dove, a postdoctoral researcher in neurobiology, care sciences and society at Karolinska Institute in Sweden.

“People with poor sleep had brains that appeared on average one year older than their actual age,” she said in a news release.

For the study, researchers evaluated brain scans for more than 27,500 middle-aged folks and seniors participating in the UK Biobank, a large-scale health research project in the United Kingdom.

Participants also provided information on their sleep quality, and blood samples were used to grade the level of inflammation in their body.

The scans showed that people’s brains aged faster as their quality of sleep diminished.

Further, inflammation explained around 10% of the link between poor sleep and accelerated brain aging, researchers said.

“Our findings provide evidence that poor sleep may contribute to accelerated brain aging and point to inflammation as one of the underlying mechanisms,” Dove said. “Since sleep is modifiable, it may be possible to prevent accelerated brain aging and perhaps even cognitive decline through healthier sleep.”

Poor sleep also might impede the brain’s waste clearance system, which is active mainly while a person is sleeping, researchers said. This could lead to increased levels of toxic substances in the brain, including amyloid beta and tau proteins that have been associated with Alzheimer’s disease.

Another way poor sleep might harm brain heath is through its effects on heart health, researchers noted.

However, the researchers noted that the study could only show an association between poor sleep and brain aging, not a direct cause-and-effect link.

More information

Harvard Medical School has more on sleep and brain health.

SOURCES: Karolinska Institute, news release, Sept. 30, 2025; eBioMedicine, Sept. 30, 2025 

What This Means For You

Getting better sleep can help protect your brain from advanced aging.