We all know that not getting enough sleep per night carries serious consequences, increasing your risk of heart disease and dementia, speeding up the aging process, weakening your immune system, making you much more liable to get into a car accident, and even prompting weight gain. But, now, an increasing body of research seems to indicate that getting too much sleep can be just as deadly, at least for your heart.
Back in August, a paper published in the Journal of the American Heart Association found that those who slept for 10 hours were 30 percent more likely to die prematurely, 49 percent more likely to develop cardiovascular disease, and had a 56 percent increased risk of stroke than those who maintained the recommended 7 to 9 hours per night. Unless you're Gwyneth Paltrow, the chances that you actually have the time to snooze for a full 10 hours per night is unlikely, so you might think this data doesn't apply to you.
But, according to a global study published Wednesday in the European Heart Journal, even anything above eight hours is bad for you. Researchers studied the data of 116,632 people in 21 countries over the course of almost eight years, and found that those who slept eight to nine hours had a 5 percent increased risk for cardiovascular disease or death. Those who slept eight to nine hours increased this risk by 17 percent, and, in corroboration with previous research, the risk jumped to 41 percent for those who slept 10 hours or more.
The authors note that given that the data of this study was self-reported, it's possible that those who slept more longer periods of time had underlying health conditions that caused them to need to rest more and contributed to early mortality. Still, for now, it seems that the sweet spot for a perfect night of sleep is six to eight hours as opposed to the previously recommended seven to eight.
There is some good news though for those of us who love a good nap. In keeping with other new research, this study found that if you don't manage to get a good night of rest, a little snooze during the day can go a long way in restoring your body and mind.
"Daytime napping was associated with increased risks of major cardiovascular events and deaths in those with [more than] six hours of nighttime sleep but not in those sleeping [less than] 6 hours a night," Chuangshi Wang, a Ph.D. student at McMaster and Peking Union Medical College in China and lead author of the study, said.
But how long that nap should be depends on what you want to get out of it, as well as what chronotype you are. For more on this, check out what the experts have to say on the length of a perfect nap.