Do you sometimes sneak in a post-lunch nap, but feel guilty about it? Some recent research will relieve your guilt.
A recent study suggests afternoon naps may be a good thing for older adults and can help them feel mentally sharper.1
But getting these memory-boosting results is all in the timing. Here’s the surprising story and how you can use the science to your advantage…
We’ve covered the napping conundrum before in our newsletters. In one study, researchers found that participants taking longer daytime naps more frequently had a higher risk of Alzheimer’s disease.2
In another study, researchers found that chronic sleepiness could serve as an important new early warning indicator of Alzheimer’s disease.3
But now, new research suggests that a carefully timed afternoon nap may be just what the doctor ordered for cognitive health.
Sleep Helps the Brain Recover
Sleep, in general, helps the brain recover from information overload as well as prepare the brain for new information to be absorbed. But there’s a fine balance involved in determining how long is too long when it comes to napping.
The study, published in the journal General Psychiatry, looked at both physical and cognitive health among 2,214 people over age 60 in China. Of these, 1,534 took regular afternoon naps while 680 did not.
Older adults who took afternoon siestas scored higher on a cognitive test than those who didn’t nap, researchers report.
Those who napped 30 to 90 minutes had better word recall – a sign of good memory – than those who skipped napping or napped longer than 90 minutes.
The moderate daily nappers also performed particularly well in working memory, locational awareness, and verbal fluency, according to the study led by Dr. Lin Sun of the Alzheimer’s Disease and Related Disorders Center at Shanghai Mental Health Center.
Conversely, those who didn’t nap or took long naps didn’t fare as well.
“In the final analysis,” the authors write, “no napping, short napping, and extended napping were associated with worse overall cognition than moderate napping.”
Be Wary of “a Second Sleep”
Dr. Charlene Gamaldo, medical director of Johns Hopkins Sleep Disorders Center, weighed in on the findings.4
She considers napping to be a good thing, but it needs to be taken in context with everyone’s unique sleep cycles and body. For example, resting more during the day may be a harbinger of poor nighttime sleep.
“In the study, naps longer than 90 minutes could have been called ‘a second sleep.’”
It can be a vicious circle as poor nighttime sleep – the kind that requires super-sized napping during the day – can lead to cognitive problems.
How to Enjoy Memory-Boosting Napping
As discussed above, there seems to be a sweet spot when it comes to napping.
According to sleep experts, the length of your nap can help determine the brain-boosting benefits.5 For instance, the 20-minute power nap is good for alertness and motor learning skills like typing and playing the piano.
What are the benefits of longer naps, often called short-wave sleep?
Research says this type of sleep is helpful for memorizing vocabulary or recalling directions. What’s more, rapid eye movement or REM sleep (occurring with 60 to 90 minutes of napping) plays a key role in making new connections in the brain and solving creative problems.6
The napping study is interesting but has some flaws, as it’s an observational study, which means people self-reported.
I don’t think there’s anything wrong with taking a short nap from time to time. According to the experts, that’s best done between 1 p.m. and 3 p.m. It’s also a good idea to keep your nap length well under 90 minutes. Set an alarm if necessary.
Most important, if you or a loved one is suffering from chronic daytime sleepiness, watch closely for memory lapses or signs of cognitive decline. Meanwhile, I’ll keep my eye on this developing area of research on how sleep affects cognitive health and report back with any new findings.