SOPHIA ANTIPOLIS, France — Napping can be a rejuvenating experience, but adding too much time to your midday power boost may do more harm than good. Researchers from Guangzhou Medical University say naps lasting longer than an hour can increase the risk of developing heart disease.
“Daytime napping is common all over the world and is generally considered a healthy habit,” says study author Dr. Zhe Pan in a media release. “A common view is that napping improves performance and counteracts the negative consequences of ‘sleep debt’. Our study challenges these widely held opinions.”
More than an hour, Dr. Zhe Pan tells the European Society of Cardiology, can pose a threat to the heart and can even lead to premature death from other causes. The study finds rest may be a case of too much of anything is not necessarily a good thing. However, just the right amount of sleep can be beneficial to the napper’s health.
Too much sleep is not good for you
Researchers analyzed data on a total of 313,651 participants from more than 20 previous studies. Just under four in 10 people (39%) took naps. In comparison to people who don’t nap, the results reveal participants who regularly napped for over one hour had a 30-percent higher risk of all-cause death and 34-percent higher risk for cardiovascular disease.
Unlike studies of the past, researchers took into account each person’s night time sleep duration. When factoring in each person’s nightly sleep length, study authors discovered a connection between longer naps and a higher risk of death and those sleeping more than six hours per night. Overall, regardless of their length, researchers find naps can increase the risk of death by 19 percent.
Women and older participants see higher risks tied to the afternoon power nap. Women who nap for any length of time see a 22-percent higher risk of death and older participants have a 17 percent higher risk, compared to participants who don’t nap.
How naps help our health
While the risk of death seems to go up, study authors conclude that short naps can help improve heath. This is especially true for those not getting enough sleep at night.
“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,” Zhe Pan states. “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.”
Researchers did not find the exact reason behind why napping has a damaging effect on the heart in this study. The team points to other studies which suggests long naps could have a connection to higher levels of inflammation. This in turn affects heart health. There have also been connections made by other studies, stating the association of napping with bad physical health, diabetes, and high blood pressure.
The findings were presented at ESC Congress 2020.