Do Naps Boost Brain Health? Keep Dreaming
Napping can be helpful after a bad night of sleep, but naps are often a sign of poor health, despite what recent headlines suggest
Advice on napping seems to flip-flop more than an insomniac tosses and turns. Now along comes a seemingly dreamy study suggesting “a daytime nap is good for the brain.” Don’t believe the headlines. The science on napping is about as settled as the incoherent remnants of a fitful dream, and naps often reflect underlying sleep and health issues.
“Our findings suggest a modest causal association between habitual daytime napping and larger total brain volume,” researchers concluded in the new study. In a press release, that conclusion was translated to: “Daytime napping may help to preserve brain health by slowing the rate at which our brains shrink as we age.”
That spawned headlines like Study Reveals Surprising Powers of Daytime Naps on Brain Health, Aging.
The study doesn’t actually support such claims.
“It does not provide evidence that napping improves brain volume or brain health,” said Andrea Spaeth, PhD, an experimental psychologist and director of the Sleep Lab at Rutgers University. Spaeth was not involved in the study but examined the scientific paper.
Rather, the findings suggest, without proving cause-and-effect, that in some older people with sleep problems or chronic health conditions, naps may slow the progression of brain shrinking that might otherwise occur. (Yes, our brains shrink as we age, and scientists are realizing that overeating and lack of exercise seem to shrink them faster.)
Which brings us back to the eternal question:
Is napping good or bad?
The answer is a clear maybe, with more caveats than the number of sheep you could ever count before nodding off. As I’ve written before:
There is evidence that afternoon naps can improve cognitive ability, boost recall after cramming for a test, tamp down impulsivity and frustration, and more generally enhance overall mental performance. But you have to add up a lot of small, mostly inconclusive studies to arrive at these tentative conclusions.
Whether naps help or hinder your health likely depends in part on how healthy you are to start with, how well you sleep generally, and how active you are each day — among many other factors.
Athletes or anyone who endures hours of strenuous physical activity — we’re not talking about someone who enjoys a daily walk or a light jog — may find physical and mental benefit in a nap, a small study earlier this year suggested. A review of such research, published in the British Journal of Sports Medicine in April, also indicated naps can improve physical and mental performance among elite athletes. That could explain why Steph Curry, Lebron James and other NBA players are nap fans.
You and me? Well, let’s look at what we actually know with certainty about nighttime sleep and daytime napping.
Sleep pressure and mixed-up cycles
The typical adult needs seven to eight hours of nightly sleep for optimal health. Some people need a bit more, others can get by on a little less. During good-quality, deep sleep, all the organs and cells in the body are repaired and rejuvenated, memories are consolidated, and the brain is literally cleaned of toxins. Insufficient or low-quality sleep damages the mind and body, leaving us cranky and drowsy in the near term and at significantly higher risk of a range of physical and mental diseases in the long run.
Because good nighttime sleep can lower stress, lessen chronic pain, boost the immune system and otherwise be a catalyst for better health, a positive cycle sets in: If we sleep well, we’re more inclined to exercise and maybe avoid that afternoon coffee and donut, which will help us sleep better. And so on.
When we don’t sleep well, a growing pressure to doze off can build during the day. Scientists actually call this sleep pressure, and along with our natural day-night body-clock rhythms, it’s nature’s way of ensuring we conk out before sleep deprivation destroys us.
So when you don’t get enough good sleep, it makes sense a nap may be in order. An afternoon nap may help compensate, at least by improving alertness the rest of the day, the science indicates, and many a happy napper like me will attest.
But any short-term benefits come with potential downsides. Napping can mess with your body clock, the circadian rhythm that governs the release of melatonin, a hormone that triggers sleepiness. And alleviating your sleep pressure — while it may feel good in the moment—risks ruining another night of sleep and ultimately training your body to rely on naps.
“When individuals fall into a habit of napping during the day, this can reduce sleep drive at night and make it difficult to fall asleep and stay asleep,” Spaeth explained in an email. “This leads to a cycle of poor sleep at night with napping during the day.”
Love ’em or hate ’em
Beyond any benefits or drawbacks to napping, some people seem predisposed, genetically or otherwise, to abhor the aftereffects. If this is you, you know the symptom: a lethargy called sleep inertia that can take an hour or more to shake.
It’s not clear what causes post-nap grogginess in some people and leaves others annoyingly cheerful. A likely explanation is that happy nappers manage to stay in the light stages of sleep, which are relatively easy to wake from, while others fall into deep sleep, which the mind desperately wishes to cling to.
All these variables in mind, sleep experts can’t say if a single nap, or a habit of napping, is categorically good or bad for any given individual.
“I consider napping to be a good thing, but it needs to be taken in the context of the person and his or her own sleep cycles and body,” says Charlene Gamaldo, MD, medical director of Johns Hopkins Sleep Disorders Center.
If you do nap, sleep experts agree it’s best to keep them short, around 30 minutes or less, and take them early in the afternoon. If you’re a coffee drinker, having a cup before your nap can help you avoid after-nap inertia.
Sleep well knowing you don’t need naps
One finding from the new study was no surprise: People who are older or who have chronic health issues are more likely to nap. A vicious cycle of indoor, sedentary, unhealthy behavior can set in, with naps acting as Band-Aids for the resulting poor sleep.
Better to address the underlying issues, experts agree.
“Many older adults are not getting sufficient exposure to natural light and do not maintain consistent routines that include physical activity during the day,” Spaeth said. “This can lead to fragmented sleep… rather than clear patterns of sleep at night and wakefulness during the day. Trying to improve daytime activity and light exposure will likely provide more benefits to health rather than frequent napping.”
If you’re not getting good sleep, you’ll know because you’re frequently tired or sluggish in the afternoons, perhaps also feeling constant stress or anxiety. You may know the typical advice for better sleep, but here are the most important suggestions:
- Set a bedtime and wake time and stick to them seven days a week.
- Get outside early in the morning so that natural sunlight, even on a cloudy day, keeps your body clock well timed.
- Walk, jog, bike, hit the gym or otherwise get daily physical activity.
- Eat a healthy, balanced diet and stop eating a few hours before bedtime.
- Avoid caffeine beyond early afternoon.
- Wind down habitually in the evening. Turn lights down or off, avoid the stress of work email, bad news, social media or horror movies.
- Avoid alcohol — it is among the most common and worst forms of sleep kryptonite.
- Develop a strategy to reduce daytime stress and anxiety.
I spell out in detail these and other sleep strategies, and the benefits of better sleep, in my sleep book, and summarize them in this Medium article.
At the end of the day, if you truly sleep well, you ought not need a nap.
“Typically, healthy adolescents and adults who are getting sufficient sleep at night do not experience a strong drive to sleep during the day,” Spaeth said. “Consolidating sleep to the nocturnal period is important for optimal health.”
But what about those of us who sleep really well most of the time, have the occasional bad night, and maybe enjoy a good nap now and then? “If someone isn’t having any issues with sleep, health or wellness,” Spaeth said, “don’t feel pressure to change anything!”
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