Taking daytime naps may help maintain brain health as we age, according to a new study. However, prior research has shown that excess napping can also be harmful.
Habitual napping was linked with larger total brain volume, which is associated with a lower risk of dementia and other diseases, according to researchers from University College London (UCL) and the University of the Republic of Uruguay.
On average, the difference in brain volume between nappers and non-nappers was equivalent to 2.5 to 6.5 years of aging, researchers said.
“Our findings suggest that, for some people, short daytime naps may be a part of the puzzle that could help preserve the health of the brain as we get older,” said senior author Victoria Garfield, a senior research fellow at UCL, in a statement.
Tara Spires-Jones, a neuroscience expert, who wasn’t part of the study, mentioned that although the research was well-done, there are some weaknesses. One of them is that people reported their own napping habits, which might not be entirely accurate.
She explained that the findings reveal a slight but meaningful increase in brain size in individuals with a specific genetic trait linked to daytime napping. This information, even with the study’s limitations, supports the idea that sleep is crucial for a healthy brain.
The main researcher, Valentina Paz, acknowledged that the study does have its drawbacks. However, she expressed confidence in the method they used for their research.
Statistical approach
In the study, which was published in a journal called Sleep Health, scientists used a special method called Mendelian randomization. They examined DNA and brain scans from 35,080 people aged 40 to 69 who were part of a big research project in the UK called the Biobank study. This project followed people in the UK from 2006 to 2010.
Mendelian randomization is a way of using genetics to understand the connection between something you’re exposed to and what happens as a result.
The researchers focused on specific parts of the genetic code that were linked to how likely a person is to take regular naps. Then, they compared the health of the brain and how well people could think between those with these nap-related genes and those without them.
The leader of the study, Valentina Paz, explained that using genes from when a person is born (set at birth) helps avoid getting mixed up with other things that might happen in life and affect how napping relates to health.
Using this method can only reveal a connection between napping and brain health, not exactly what causes what. Also, they didn’t know how long people napped, which can make a difference in whether it’s good or not for sleep.
Paz explained that earlier studies indicate that a quick nap (between 5 to 15 minutes) in the early afternoon might be helpful for those who need it.
Napping can be harmful too
Meanwhile, previous research has shown that frequent napping or regularly napping for extended periods during the day may be a sign of early dementia in older adults.
Elderly adults who napped at least once a day or more than an hour a day were 40% more likely to develop Alzheimer’s than those who did not nap daily or napped less than an hour a day, according to a study published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, in March 2022.
And in July 2022, a study found that people who often nap have a greater chance of developing high blood pressure and having a stroke.
People who regularly took daytime naps were 12% more likely to develop high blood pressure and 24% more likely to have a stroke compared to those who didn’t nap.
A sleep expert, Dr. Raj Dasgupta, explained that napping too much could indicate an underlying sleep problem. These sleep issues can lead to higher levels of stress and hormones that affect weight, potentially causing problems like obesity, high blood pressure, and diabetes. This, in turn, increases the risk of heart disease.
SOURCE:CNN