Napping improves your alertness, bolsters your memory and boosts your mood. But naps aren’t all good. Recent research in the American Heart Association’s Hypertension reveals that regular napping is actually associated with an increased risk of high blood pressure and stroke.
The Negatives to Napping
Naps have long been championed for their health benefits, but researchers have now begun to investigate whether napping during the day could contribute to higher blood pressure and strokes.
Using a combination of observational and genetic analysis, one team of researchers has found that people who take frequent naps have a 12 percent higher risk of high blood pressure, as well as a 24 percent higher risk of stroke.
They also found that these risks were worse for younger folks. While nappers under the age of 60 faced a 20 percent increase in the likelihood of developing high blood pressure in comparison to individuals who never nap, nappers over the age of 60 faced only a 10 percent increase.
“These results are especially interesting since millions of people might enjoy a regular, or even daily nap,” says E. Wang, a corresponding author and an anesthesiology professor and chair at Xiangya Hospital Central South University, in a press release.
To arrive at their findings, the team turned to the U.K. Biobank, a biomedical database featuring information about approximately 500,000 U.K. participants aged 40 to 69. These participants routinely provided the Biobank team with samples of their blood, urine and salvia, as well as their responses to regular surveys about their health and health-related habits.
Researchers removed any of the participants who started with high blood pressure or strokes and tracked the development of these health concerns among the remaining 360,000 participants. They tracked their self-reported napping habits over an average period of around 11 years. In addition to this analysis, the researchers also took a genetic approach, known as Mendelian randomization, to assess some participant’s risk.
Researchers found that the participants who normally took naps had higher likelihoods of high blood pressure and strokes. They also discovered that a person’s risk of high blood pressure increased by about 40 percent if their napping frequency increased from “never” to “sometimes,” or from “sometimes” to “usually.”
Though the study cannot prove which biological mechanisms contribute to this increased risk, researchers theorize that the increase could connect to the various underlying health issues that can cause people to take naps.
“Although taking a nap itself is not harmful, many people who take naps may do so because of poor sleep at night,” says Michael A. Grandner, a psychologist unassociated with the study and the director of the University of Arizona's Sleep Health Research Program, in a press release. “Poor sleep at night is associated with poorer health, and naps are not enough to make up for that.”
Ultimately, the researchers say that additional analysis of the connections between napping and heart health are needed.