Getting a good night’s sleep is important for feeling rested, but new research shows it may also protect the brain from aging too quickly.
A large study from Karolinska Institutet in Sweden suggests that poor sleep habits are linked to brains that appear older than their actual age.
The study, published in eBioMedicine, analyzed brain scans from more than 27,500 middle-aged and older adults in the UK Biobank.
Using advanced machine learning, researchers estimated each participant’s “brain age” by examining over a thousand features from MRI images.
They then compared this brain age to the participants’ real, chronological age.
Sleep quality was measured using five self-reported factors: whether people identified as morning or evening types, sleep duration, insomnia, snoring, and daytime sleepiness.
Each person was given a score and placed into three groups: healthy sleepers, intermediate sleepers, and poor sleepers.
The results were clear. People with poor sleep habits had brains that looked older than their real age.
In fact, for every one-point drop in sleep score, the gap between brain age and real age widened by about six months.
On average, those in the poor sleep group had brains that appeared one year older than their actual age.
Abigail Dove, the study’s lead author, explained that inflammation in the body could be part of the reason.
Blood tests showed that people with poorer sleep also had higher levels of low-grade inflammation, which is known to affect the brain. Inflammation explained just over 10 percent of the link between poor sleep and brain aging.
“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 something we can change, it may be possible to prevent brain aging and even reduce the risk of cognitive decline by improving sleep habits.”
The researchers noted other possible explanations as well. Poor sleep might reduce the brain’s ability to clear away waste, a process that happens mainly during sleep. It may also harm cardiovascular health, which is closely tied to brain function.
The study has some limitations.
Because sleep quality was self-reported, the results rely on people’s own descriptions rather than objective measures.
Participants in the UK Biobank are also generally healthier than the wider population, which may affect how well the findings apply to everyone.
Still, the research adds to growing evidence that getting enough good-quality sleep is not only vital for daily health but may also help keep the brain younger for longer.
Source: Karolinska Institutet.
