Researchers followed 3462 people, ages 35 to 75, for 5.3 years and found that those who nap once or twice a week had a much lower risk of heart disease, while those who napped more frequently than twice a week had the same risk for heart disease as those who did not nap. They explained this strange result by showing that many of the frequent daily nappers are at increased risk for heart disease because they were more likely to be older, male, cigarette smokers and/or obese. They were also likely to sleep much longer at night. When they removed these people who were at high risk for heart attacks from their data, there was no increased risk for heart attacks in those who napped more than twice a week (Heart, Dec, 2019;105(23):1768-1769).
Conflicting Studies on Napping and Heart Attack Risk
The frequency of daytime napping increases with age, and up to 70 percent of older adults around the world take daytime naps. A review of the world’s scientific studies shows tremendous disagreement on whether daytime napping is healthful or harmful (JAMA, Nov 20, 2019;322(22):2158-2159). Different studies show that habitual nappers:• are significantly less likely to die from heart attacks,
• are at increased risk for dying of heart attacks, or
• are just as likely to suffer heart attacks as people who do not nap.
Virtually all of these studies on napping and heart attack risk are observational, comparing people who nap with those who do not nap. This type of study can show associations but they do not show cause-and-effect.
