This may not be a dilemma that huge numbers of people grapple with regularly. But a new study suggests that if you’re watching your blood pressure, taking a midday nap may be a step in the right direction. It’s long been known that naps, when done right, can leave you feeling refreshed and energized. Whether they carry any immediate cardiovascular benefits has been less clear, even though this could affect the health of millions of people around the world. “We all know that lifestyle changes represent the cornerstone of treatment” for high blood pressure, says Manolis Kallistratos, MD, a cardiologist at Asklepieion General Hospital in Voula, Greece. “We also know that certain cultures have the habit of sleep during midday.” These two observations led Dr. Kallistratos and colleagues to investigate the effects of napping on blood pressure in a number of different ways.
Similar Effect as Other Lifestyle Changes
Kallistratos and his investigative team had already found that naps were associated with lower blood pressure, and fewer blood pressure medications, in people with serious hypertension. But for the latest study — presented at the American College of Cardiology 2019 meeting in New Orleans on March 18 — they wanted to find out if a similar effect could be seen in the much larger category of people whose blood pressure is fairly well controlled, but who could still benefit from lower levels. “A drop in blood pressure as small as 2 millimeters of mercury [mmHg] can reduce the risk of cardiovascular events such as heart attack by up to 10 percent,” Kallistratos notes, so even an improvement that doesn’t seem drastic could have an enormous effect when multiplied across an entire population. The study included 212 adults with an average age of 62, whose average systolic blood pressure was 129.9 mmHg. Each wore a blood pressure monitor for 24 hours, during which some participants took a midday nap and some didn’t. Among those who took a nap, the average duration was 49 minutes. After controlling for age, sex, medications, and lifestyle factors like physical activity, smoking status, and alcohol, coffee, and salt intake, the researchers found that participants who napped had systolic blood pressure that was 5.3 mmHg lower, on average, than in those who didn’t nap. For comparison, Kallistratos points out, lifestyle changes like reducing salt or alcohol intake tend to reduce blood pressure by 3 to 5 mmHg, and a low-dose drug for hypertension typically lowers levels by 5 to 7 mmHg.
License to Snooze (a Little)
There are reasons to be confident that the lower blood pressure seen in study participants who napped was, indeed, related to that difference and not some other factor. One reason is that both sets of participants saw a similar drop in blood pressure while sleeping at night. This means that the lower average blood pressure seen in the napping group didn’t reflect any apparent differences in nighttime sleep. Another is that both groups were similar in terms of heart disease risk factors, except that there were more smokers in the napping group. Since smoking isn’t known to lower blood pressure, this points even more strongly to napping as the decisive difference. In conclusion: “We don’t want to tell people to be lazy,” says Kallistratos. “But if a person gets the sense of needing to sleep during the day for 45 minutes to an hour, it’s okay.”
