When you struggle to sleep at night, daytime naps can feel as though they’re the only thing keeping you sane. Unfortunately, it appears that napping too often may be associated with an increased risk of developing type 2 diabetes.
A 2016 Finnish study published in the journal Sleep Medicine asked over 12,000 individuals between 33 and 60 years of age how often they took daytime naps.
The specific question asked was, “Do you sleep during the daytime (take naps)?”
The five available responses to the question were:
- No need
- I would like to but I cannot sleep during the daytime
- On two days weekly or more seldom
- On three to five days weekly
- Every or almost every day
During the 14-year follow-up period, there were 356 cases of type 2 diabetes. Using the “no need” category as the reference, researchers found that there was a significant increase in the risk of type 2 diabetes in those who napped most frequently.
After adjusting for age and gender, those who reported napping every (or almost every) day were almost two times more likely to develop type 2 diabetes compared to those who did not feel a need to nap.
Even after adjusting for lifestyle issues such as work hours, alcohol use, smoking history, and snoring, the risk remained virtually the same.
Researchers did discover that when adjusting for body mass index (BMI), the association became non-significant. This suggests that napping is not an independent risk factor for type 2 diabetes; other factors are at play, too.
A link between daytime napping and type 2 diabetes?
Researchers still don’t know for sure why there appears to be a link between daytime napping and type 2 diabetes. Since napping and type 2 diabetes are more common among older adults, the link may be coincidental.
Furthermore, those already at a higher risk of type 2 diabetes, such as those with a high BMI or those struggling with obesity, may be more likely to take daytime naps, hence the association.
Frequent (and long) daytime naps may also be an indicator of another health condition that could increase diabetes risk.
Should I avoid napping entirely?
If you have the opportunity to take a nap during the day, particularly after a bad night of sleep, you should take it! However, it’s best to limit your nap to between 10 and 45 minutes so you don’t enter deep sleep (which can result in you feeling groggy and unrefreshed when you wake up) and to nap no later than 4 p.m. (Napping late in the day can reduce sleep pressure and make it more difficult to fall asleep at night.)
Naps, and simply resting in the middle of the afternoon, can help improve mood, improve cognitive performance, and make you feel more alert. In fact, even a 10-minute nap can help combat the effects of nighttime sleep deprivation.