Named the amazing effect of a short daytime sleep on the brain

Short naps may help protect brain health with age, the researchers suggested, finding that the practice appears to be associated with increased brain volume.

While previous research has suggested that long sleep may be an early symptom of Alzheimer’s disease, other work has shown that short sleep can improve people’s learning ability.

Now researchers say they have found evidence that naps may help protect against brain shrinkage.

This is of interest, the team says, because brain shrinkage, a process that occurs with age, accelerates in people with cognitive problems and neurodegenerative diseases, and some research suggests it may be related to sleep problems.

“According to these studies, we found an association between habitual daytime sleep and an increase in total brain volume, which may indicate that regular daytime sleep provides some protection against neurodegeneration by compensating for poor sleep,” the researchers note.

In an article published in the journal Sleep Health, researchers at UCLA and the University of the Republic of Uruguay report that they used data from a British Biobank study that collected genetic, lifestyle and health information from 500,000 people. between the ages of 40 and 69 when applying for a job.

The team used data from 35,080 Biobank participants to see if a combination of genetic variants that were previously associated with self-reported habitual daytime sleep was also associated with brain size, cognition and other aspects of brain health.

Given that such options are set at birth and are assumed to be randomly distributed, the approach allows researchers to investigate the effects of daytime sleep on the brain by reducing the influence of lifestyle factors that can affect people’s sleep habits and brain health, such as smoking or physical activity. .

“It looks like a natural randomized control trial,” said Dr Victoria Garfield, co-author of the study at University College London, adding that the options were fairly common. “They are present in about 1% of the population, which is actually quite a lot of people.”

Indeed, although at first it seemed that participants who reported never or rarely sleeping during the day had larger total brain volume, the team found an inverse relationship when they looked at the genetic predisposition to sleep, suggesting that the initial finding could be due to other confounding factors. relationship between daily sleep intake and brain size.

Overall, the team found an association between a genetic predisposition to habitual daytime sleep and an increase in brain volume, equivalent to a 2.6-6.5 year reduction in life expectancy, although there was no association with cognitive measures such as reaction time.

“Perhaps a short nap … could help preserve brain volume, and this is a positive thing, potentially, [для] prevention of dementia,” says Victoria Garfield, adding that previous studies have shown that sleeping up to 30 minutes can be beneficial.

Dr. Garfield noted that there are many risk factors that can lead to dementia, while many other factors can also affect brain volume.

What’s more, the study is based on white British data only, and the exact length of daytime sleep associated with benefit is unclear. It’s also unclear whether the same benefits of daytime naps will be seen in people without predispositions.

Professor Tara Spiers-Jones, President of the British Neurological Association, Team Leader at the British Dementia Research Institute and Associate Director of the Center for Discovery in the Brain Sciences at the University of Edinburgh, welcomed the study, although she said it had limitations, including the British habit of doze, which they report themselves. “This study is important because it adds to the evidence that sleep is important for brain health,” she said.