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

Recent study finds that napping may keep your brain up to six years younger

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In the past, experts have confirmed that short naps may have the potential to boost cognition, focus, and memory. However, new research has unveiled a possible association between a genetic predisposition toward napping and greater brain volume, a key indicator of brain health.

Study Findings Explained

A recent study published in Sleep Health sought to identify a causal relationship between daytime napping, cognitive function, and brain volume. The study was conducted by University College London, the University of the Republic in Uruguay, and The Broad Institute in Massachusetts.

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.

“This study hopes to show an association between daytime napping and preserving brain health by slowing the rate at which our brains shrink as we age. I would be cautious about saying that napping is good for brain health, as napping can lead to poor overnight sleep. Whether the study reveals a causal connection between napping and brain health remains unclear,” Dr. Raj Dasgupta, told The Epoch Times in an email.

How Is Brain Volume an Indicator of Brain Health?

One way brain health can be calculated is through the measurement of a person’s brain volume, which is determined by the amount of brain tissue present. Typically, higher brain volume indicates better brain health and decreased mortality risk.

“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.”

It is important to note that brain atrophy can also be caused by injury or chronic illness. In these cases, naps are unlikely to provide any meaningful protection against degeneration stemming from these medical causes.

How Naps Affect Brain Function

Recent research has confirmed that short naps have the power to boost cognition. Naps can also contribute to better long-term memory and information retention compared to taking a break or cramming information.

The length of the nap is a critical factor since longer naps have actually been shown to decrease cognition rather than improve it.

“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.

“Sleep problems are common in older adults,” he said. “The amount of sleep needed stays constant throughout the adult years. In older adults, sleep is less deep and choppier than sleep in younger people. In general, short naps lasting 15-20 minutes don’t affect nighttime sleep quality for most people, but excessive napping may disrupt nighttime sleep patterns, leading to sleep deprivation and compromised sleep quality.”

Conflicting Research

The difference between genetic disposition and nap length may explain why recent research is inconsistent about whether naps have a positive impact on a person’s overall long-term health.

One study confirmed that short daytime napping decreased the risk of cognitive decline in older adults. However, another study found a link between frequent napping and a higher risk of high blood pressure and stroke.

The duration of the nap seems to be a critical factor. A study published in the Journal of the American Geriatrics Society discovered that older adults who did not nap and those who took extended naps (greater than 90 minutes in duration) were significantly more likely to have decreased cognition, while napping after lunch for a moderate amount of time improved cognitive performance.

A subsequent study published in Frontiers in Neuroscience also found that older adults who napped longer than 90 minutes experienced decreased cognitive function. Another study published in the Journal of the Alzheimer’s Association reported a link between “excessive” napping and Alzheimer’s disease.

“Older adults tended to nap longer and more frequently with aging, while the progression of Alzheimer’s dementia accelerates this change by more than doubling the annual increases in nap duration/frequency. Longer and more frequent daytime naps were associated with higher risk of Alzheimer’s dementia,” Dr. Dasgupta explained.

Are Frequent Naps Helpful or Harmful in the Long Term?

While this new study is promising, it has some notable limitations according to Dr. Dasgupta, including the population studied (those with a genetic predisposition to napping versus the general population), lack of a standardized definition of a nap, and the lack of data regarding the participants’ specific napping habits.

“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.”