For many among us, a nice afternoon nap is a cherished opportunity to take a break, recharge, and wake up feeling reinvigorated. Unfortunately, a new set of research just released by the European Society of Cardiology has a warning for all the habitual nap-takers out there.
Keep your naps under an hour, because any longer is associated with a significantly higher risk of all-cause death and or the development of cardiovascular disease.
This isn’t the first time that the relationship between napping, mortality, and cardiovascular disease has been investigated, but all of those prior projects had produced middling or inconclusive results at best. So, this study’s authors performed a comprehensive analysis of a dataset featuring over 300,000 people (313,651 to be exact) gathered from more than 20 previous research initiatives. Among that enormous cohort, 39% of participants were regular nap-takers.
That investigation yielded some eye-opening results. In comparison to no napping at all, napping for over 60 minutes was associated with a 30% higher chance of death by any cause and a 34% greater risk of developing cardiovascular disease.
Interestingly, however, when the research team accounted for nighttime sleep habits (average time spent asleep), long naps specifically were only linked to an increased risk of death among adults sleeping more than six hours per night. This suggests that long naps may be especially detrimental when they’re largely unnecessary due to adequate time spent asleep in the evening.
All in all, though, naps of any length were associated with a 19% higher chance of death. The harmful effects of naps appear to be most prevalent among women (22% greater chance of death) and older adults (17% greater chance of death).
“Daytime napping is common all over the world and is generally considered a healthy habit,” comments study author Dr. Zhe Pan of Guangzhou Medical University, China, in a press release. “A common view is that napping improves performance and counteracts the negative consequences of ‘sleep debt’. Our study challenges these widely held opinions.”
The findings weren’t all bad news for nap lovers. For people who struggle to attain 6-8 hours of sleep each night, the occasional short nap may actually be beneficial from a cardiovascular disease risk perspective.
“The results suggest that shorter naps (especially those less than 30 to 45 minutes) might improve heart health in people who sleep insufficiently at night.” Dr. Pan adds.
Still, the research team concludes that if you aren’t already in the habit of napping during the day, and usually get enough sleep at night, it’s probably a good idea not to change up your routine. Additionally, occasional naps should be kept to 30 or 45 minutes at the longest.
“If you want to take a siesta, our study indicates it’s safest to keep it under an hour. For those of us not in the habit of a daytime slumber, there is no convincing evidence to start.” Dr. Pan suggests.
The notion that something as essential as sleep can harm us sounds nonsensical at first, and researchers can’t say for sure exactly why napping appears to impact the body negatively in certain scenarios. That being said, sleeping for long periods has been linked to higher levels of bodily inflammation, which is never a good thing when it comes to heart health and overall life expectancy.
There’s a centuries old saying, made famous most recently in 1994 by legendary rapper Nas, that goes “sleep is the cousin of death.” This study lends some credence to that statement.
This research is set to be presented at the ESC Congress 2020.