Frequent Napping May Increase Risk for High Blood Pressure By 12%, A New Study Suggests
Since research proves that getting sufficient sleep is one of the most important ways to rebuild muscle, "clean out" the brain, cement new memories, reduce risk for heart disease, decrease inflammation and rejuvenate energy levels for the day ahead, we all know the importance of scoring enough zzz's.
Last month, a new study reported that the "sweet spot," or optimal amount of sleep for the brain, is about seven hours per night. But what is a busy (or, TBH, often super-stressed) human to do when it doesn't feel possible to score all seven hours at night? Nap, of course. It's a wise way to fill in any R & R gaps, right?
Not so fast, reports a new study published in the American Heart Association journal Hypertension: Individuals who frequently or usually take daytime naps tend to have a 12% higher risk of high blood pressure and a 24% higher risk of having a stroke later in life compared to those who never nap.
Read on to learn more about why daytime sleep might be a sign of a larger health challenge, plus how to adjust your lifestyle to get enough restorative shut-eye at night.
What This Heart Health Study Found
Before we go any further, it's important to note that napping itself is not an unhealthy habit. In fact, a 10- to 20-minute nap in the early afternoon is actually A-OK as a once-in-a-while choice, Mayo Clinic experts confirm. Doing so on infrequent days when you're lagging can be a boon for alertness levels, mood and physical and cognitive performance, all while reducing fatigue.
The healthy habit can be a not-so-great sign about your cardiovascular health when the naps feel like a daily must or a frequent pattern, though. To land at these findings, a group of Chinese researchers turned to the UK Biobank, a massive biomedical database and research hub. From the Biobank, they selected about 500,000 people aged 40 to 69 who lived in the United Kingdom between 2006 and 2010. Participants who had a stroke in the past or had a high blood pressure diagnosis prior to the study were excluded, leaving a pool of about 360,000 people.
Participants regularly provided blood, urine and saliva samples, and also self-reported their nap frequency in one of three categories: "never/rarely," "sometimes" or "usually."
From this data, the scientists found that:
- Compared to never-nappers, those who usually napped had a 12% higher chance of developing high blood pressure and 24% higher chance of having a stroke later in life.
- People who were younger than 60 who fell under the "usually" nap umbrella had a 20% higher risk of developing high blood pressure during the duration of the study compared to their same-aged peers who never napped.
- "Usual" nappers were more likely to identify as men, have lower education and income levels, report cigarette smoking daily, say they drink alcohol daily, suffer from insomnia and consider themselves an "evening person."
- About 3 in 4 participants stayed in the same nap category from the start to the end of the study.
- Each increase in the nap category (from sometimes to usually or from never to sometimes) increased risk for high blood pressure by 40%.
- Those who napped frequently tended to have a genetic predisposition to high blood pressure.
"These results are especially interesting since millions of people might enjoy a regular, or even daily nap," E Wang, Ph.D., M.D., a professor and chair of the department of anesthesiology at Xiangya Hospital Central South University and the study's corresponding author, tells the AHA Newsroom.
While occasionally napping is not in itself a harmful habit, many people who fall back on naps might be choosing to do so because of poor sleep during usual nighttime hours.
Research suggests that smoking and consuming certain foods and drinks (including sugar, caffeine and alcohol) can lead to more interrupted and less restorative sleep. As can sleep disorders such as sleep apnea, which has been proven to increase the severity of heart disease.
"Poor sleep at night is associated with poorer health, and naps are not enough to make up for that," Michael A. Grandner, Ph.D., M.T.R., a sleep expert and co-author of the AHA's new Life's Essential 8 cardiovascular health score, adds to the AHA Newsroom. "This study echoes other findings that generally show that taking more naps seems to reflect increased risk for problems with heart health and other issues."
The Bottom Line
This sleep study determined that the need to nap, while not inherently unhealthy, might be a signal that the body is not getting enough sleep at night. That sleep scarcity could be the result of a larger health issue or lifestyle habits that might predispose one to high blood pressure or stroke.
More research is needed regarding the impact of daytime nap length, using a more diverse study group (this one included only middle-aged and elderly people of European ancestry), to home in on exactly why naps might relate to heart health.
As scientists investigate further, this study can serve as another reminder to double down on sleep hygiene to try to rack up the best sleep that you can at night—optimally around seven to nine hours. Seek out smoking cessation resources if you smoke, drink alcohol in moderation and adjust your bedroom design and temperature to promote restful sleep. What you eat can play a major role, too. Try our 3-day meal plan for better sleep to set yourself up for snooze success, and be sure to stock up on these 9 foods dietitians swear by for better sleep during your next grocery run.