Study finds a startling link between taking long naps and death risk

Taking a short nap during the day may improve your health, assuming you get too little sleep at night, but a new study warns that taking long naps during the day may have the opposite effect. Researchers have linked naps that last longer than an hour with a spike in one's risk of death; the findings come from an analysis of data on more than 313,000 people sourced from around 20 past studies.

Generally speaking, according to the study from Guangzhou Medical University's Dr. Zhe Pan, napping for less than 60 minutes during the day isn't linked to an increased risk in death from cardiac-related incidents. However, based on the data the team analyzed, sleeping more than 60 minutes during the day may cause a big increase in your risk of dying compared to those who don't nap during the day.

The all-cause death risk was found to be 30-percent higher in these people — the long-duration daytime nappers — and the cardiovascular death risk was found to be 34-percent higher. When the researchers factored in how much sleep these people got at night, they found that the increased death risk only applied to people who also got more than six hours of sleep every night.

Though shorter naps weren't linked to a greater risk of developing cardiovascular disease, the study did note that any duration of napping during the day was linked to an overall 19-percent increase in death risk. Women were found to have a greater risk compared to men at 22-percent, plus older participants also experienced a 17-percent greater risk compared to younger people.

These new findings build upon past research, which has historically had 'conflicting' results. It's unclear why napping is so strongly associated with an increased risk of death, but the researchers note that high levels of inflammation may play a role in this. As well, daytime napping is linked to other conditions that may shorten lifespans, such as high blood pressure and diabetes.