Long Naps Linked to Type 2 Diabetes

You can have too much of a good thing. We’ve seen that midday naps may help lower blood pressure and be beneficial to your heart, but a 2016 study from Japan finds napping for too long may increase risk of type 2 diabetes. 

Researchers from the University of Tokyo analyzed data on more than 300,000 people included in 21 studies that looked at links between napping and health. Results showed people who napped for an hour or more each day saw a 45% increased risk for type 2 diabetes. Shorter naps (40 minutes or less) had no effect on diabetes risk, nor did skipping naptime altogether. 

Though researchers can’t say for sure if this is cause-and-effect, there is good evidence to suggest keeping naps short if they are a part of your usual routine. The National Sleep Foundation advises short naps of 20 to 30 minutes can help to improve mood, alertness and performance. Anything longer than that may leave you feeling groggy or interfere with nighttime sleep. 

While it’s fine to indulge in your annual post-Thanksgiving dinner snooze, for the rest of the year keep naps short and practice good sleep hygiene to ensure a quality nighttime rest. Aim for seven to eight hours of sleep per night—a Dutch study found much less or much more sleep may be linked to lower insulin sensitivity, a precursor to type 2 diabetes. 

BONUS: Lower risk of type 2 diabetes could mean lower risk of dementia, too. Compared with people without diabetes, men with diabetes had a 70% greater risk for developing vascular dementia, and a 120% greater risk in women.

Published November 1, 2016