Everyone loves a good nap -- most mammals do it, some reptiles do it, and humans absolutely love it -- there's an unofficial American holiday dedicated to naps (the Monday after Daylight Savings Time goes into effect is National Nap Day). Even in Ancient Rome, afternoon napping was quite common. Now, a new study shows as snooze can cut back on heart attacks too.
Research published by the American College of Cardiology has found that those who take advantage of a midday nap were apt to have lower blood pressure compared to those that didn’t. The study showed that naps were associated with an average 5 mm Hg drop in blood pressure. That’s on par with other blood pressure-lowering interventions, such as salt and alcohol reduction (3 to 5 mm Hg) and antihypertensive medications (5 to 7 mm Hg).
"Midday sleep appears to lower blood pressure levels at the same magnitude as other lifestyle changes. For example, salt and alcohol reduction can bring blood pressure levels down by 3 to 5 mm Hg," said Manolis Kallistratos, MD, cardiologist atthe Asklepieion General Hospital in Voula, Greece, and one of the study's co-authors.
This is the first study to test the effect a midday’s nap on blood pressure. It focused on 212 people over the age of 62 with a mean blood pressure of 129.9 mm Hg over a twenty-four-hour span. About one out of four participants were smokers and/or had Type 2 diabetes.
Researchers assessed and recorded the subjects’ midday sleep time (the average duration was 49 minutes), lifestyle habits (such as physical activity levels and alcohol, coffee and salt intake), along with pulse wave velocity, a measure of stiffness in the arteries.
The analyses were adjusted for aspects known to impact blood pressure levels, including gender, medications, age, and lifestyles. There were no differences in terms of the number of antihypertensive medications taken between the two groups, and the pulse wave velocity tests and echocardiograms were also comparable.
The participants of the study were able to undertake the test during routine daily living, wearing an ambulatory blood pressure monitor in order to measure and track blood pressure at regular intervals, instead of a singular reading at the clinic. At study recruitment, the subjects also underwent an echocardiogram, an ultrasound of the heart that shows its structure and function.
"These findings are important because a drop in blood pressure as small as 2 mm Hg can reduce the risk of cardiovascular events such as heart attack by up to 10 percent," Kallistratos said. "Based on our findings, if someone has the luxury to take a nap during the day, it may also have benefits for high blood pressure. Napping can be easily adopted and typically doesn't cost anything."
Of course, it's a fairly small sample size and the cause-effect has not been thoroughly explored, but results warrant further study. More sleep, in general, has been associated with better help, providing a myriad of health benefits. It's not exactly clear to what extent the improvement is owed to extra rest or, in particular, to the "nap"-like nature of the extra rest.
According to the site Better Sleep, Better Life, employees can cost employers as much as $3,200 for health care costs that cover sleep-related problems and overall, U.S. industries lose up to $150 billion each year because of reduced productivity, absenteeism, and other sleep deprivation reasons. So, the next time your boss finds you asleep, tell them it’s for your health -- and their benefit.
The results have not yet been peer-reviewed. Kallistratos will present the study, "Mid-day Sleep Effects as Potent as Recommended Lifestyle Changes in Patients With Arterial Hypertension" at the 2019 ACC.
Edit: the initial version of this article featured a case of mistaken authorship. A later edit rightfully credited the article to its author.
