There’s no doubt about it – taking a nice, leisurely nap feels good in the moment, but what does it do for your overall health? Studies have offered mixed results, with some suggesting that regular, brief naps actually improve mental functioning and overall health, and others indicating that taking too many too-long naps could actually reduce the length of your life, among other negative health effects.
To complicate matters, the act of sleep is generally considered to be a very important part of a healthy lifestyle.
Napping to make up for hours of lost sleep might be a bad idea, though, as a recent study suggests that the length of your nap has a lot to do with how it affects your health. It indicated that excessively long naps could increase the risk of diabetes.
Heavy Nappers Have Higher Blood Sugar
In order to conduct their study, researchers from the Netherlands’ Leiden University Medical Center examined 27,000 retired women and men, all of whom were Chinese. The subjects were divided into four separate groups according to how long they typically napped, with some of the subjects reporting not napping at all and others saying that they napped for up to an hour per day or even more.
Nearly 18,500 of the subjects said they regularly took naps in the afternoon, even if they were brief. When comparing the health metrics of the four groups with one another, the researchers found that those who took the longest naps were significantly more likely to develop prediabetes and diabetes than those who didn’t nap at all. However, those who took regular naps lasting less than half an hour were actually less likely to develop diabetes than those who never napped. However, this difference was so small that the researchers said it fell within the study’s margin of error.
According to Eliane Lucassen, one of the lead researchers behind the study, taking an extended nap once in a while is probably harmless and even necessary when you’re running on very little sleep from previous nights. However, taking extended naps regularly could do more harm than good for your health.
Confirming the Results of a Previous Study
If anything about the study is most surprising to a Western audience, it’s probably the high percentage of study participants who napped regularly. Napping is more common in China than it is in America, and it’s common among young people as well as the older individuals surveyed in the study. For this reason, the researchers don’t believe that the study results were due to people being tired from diabetes and deciding to nap for longer periods as a result.
The new study actually confirms the findings of a 2010 study on napping that also focused on Chinese subjects. In this study, individuals who said they napped between four and six days every week were at approximately 50% greater risk for developing diabetes as compared to those who didn’t nap as often. The researchers in this study also concluded that excessive napping increases diabetes risk, rather than the other way around.
The question, then, is how napping actually increases the risk of developing diabetes. Diabetes is a condition in which blood sugar levels are excessively high due to insulin resistance in the cells or an inability of the body to remove extra blood glucose through insulin production.
According to the researchers, one possibility is that sleeping too little at night and trying to compensate for it by napping during the day may interfere with the body’s internal clock which regulates bodily processes, including insulin production. However, brief naps lasting 15 or 30 minutes may be too short to cause this type of interference.
The Bottom Line
Taking naps too frequently and sleeping too long during each nap could increase your risk of developing high blood sugar and diabetes, according to a recent study.
The full text of the study is available online in Sleep Medicine.