‘Power Naps’ May Help Slow Brain Aging—For Some People

The study relied on genetic markers that have been strongly linked to habitual napping in previous genome-wide association studies. Using data from the UK Biobank, 92 genetic variants previously associated with habitual napping were analyzed among the study’s 378,932 participants. The researchers then compared people with three sets of these genetic traits to others, looking at total brain volume, hippocampal volume, reaction time, and visual memory of the participants.
The researchers discovered that people with these specific genetic characteristics were more likely to have a higher brain volume, and thus better brain health, as our brain tends to shrink as we age. The study specifically revealed a 15.8 cubic centimeter increase in total brain volume, which is approximately equivalent to 2.6 to 6.5 years of brain age.
No differences were noted in hippocampal volume, reaction time, and visual memory between those with a genetic predisposition to napping and those without.
Because the study focused specifically on people with a genetic predisposition to napping, it remains unclear whether habitual napping benefits the brain health of the general population. In other words, perhaps only people that are genetically predisposed to napping can preserve brain volume through napping. Those without a genetic predisposition to napping may have different sleep habits or other factors that make napping less relevant to brain health.
Being both a researcher and a clinician in a sleep clinic, Shade thought the genetics component was a novel addition to the study, and that it reflected in part what he sees in the clinic.
“Some people have a daily nap and that’s just them, and others can’t nap,” he said. “If you don’t need to nap, you shouldn’t.”
Dr. Raj Dasgupta—a quadruple board-certified physician specializing in sleep medicine, internal medicine, pulmonology, and critical care—was less certain about the findings of the study.
“In general, it is normal for people to lose some brain cells and brain volume as they get older, but there is a term called ‘brain atrophy’ when a person has more brain changes than expected for their age,” said Dr. Dasgupta.
“Here, the damage happens faster than the typical aging process. People with brain atrophy can have problems with thinking, memory, and performing everyday tasks. The greater the loss, the more impairment someone has. Both whole-brain and regional volume declines are associated with cognitive impairment and dementia.”
“In general, short naps in sleep deprived individuals that occur around noon to 2:00 p.m. and are 15-20 minutes in duration can positively impact brain function by enhancing memory consolidation, cognitive performance, emotional regulation, and creative thinking,” explained Dr. Dasgupta.
“These power naps can boost alertness and focus, making them beneficial to brain function. However, studies show that people who sleep too much or too little chronically have poor health and even a shorter life span.”
Dr. Dasgupta also cautioned against excessive napping, citing its effect on nighttime sleep.
“Napping, like sleep, is very individualized and it is safe to say napping isn’t for everyone,” Dr. Dasgupta explained.
“Some individuals simply can’t nap during the day or have a hard time napping in places other than their own beds. Napping can also have negative effects, such as sleep inertia, which is feeling groggy and disoriented after waking up from a nap especially if the nap is too long. Napping may also cause nighttime sleep problems for individuals who suffer from chronic insomnia making it even more difficult to initiate sleep and maintain sleep at night.”