There is nothing more divine… than nap during the day, during lunch break or after eating – in the case of the weekend! A small pleasure that allows you to recover after a morning of intense work, perhaps after a difficult night, to regain energy and complete all the activities. While this appears to be an effective form of recharge, it may not be as health-friendly as it appears. A study published in Hypertension, a journal of the American Heart Association (AHA), would reveal worrying implications: the official scientific journal reports a research carried out on people who often take a nap during the day. Well, they would be exposed to increased chances of suffering from high blood pressure and having a stroke.
The negative effects of napping in numbers
A group of Chinese researchers was led by scientists from the National Clinical Research Center for Geriatric Disorders at Xiangya Hospital Central South University in a search for evidence of the effect of napping on health. The study, coordinated by professor and chairman of the Department of Anesthesiology E. Wang, took into consideration the data of 500,000 people aged between 40 and 69 years. The information was retrieved from UK Biobanka biomedical database collecting genetic and health information from half a million volunteers in the UK.
Among the medical data, collected between 2006 and 2010, those of 358,451 participants who had never previously suffered from hypertension or stroke were extrapolated so as not to distort the results. The volunteers involved provided regular urine, blood and saliva samples, also lending themselves to a survey on the frequency of daytime naps over the four years. However, the study only took into consideration the frequency of the nap but not the duration, relying on the simple self-reports of the participants. The purpose of the research was to check the effects of the nap and the numbers are clear: participants who used to sleep daily were 12% more likely to develop hypertension and 24% more likely to suffer a stroke than those who did not get daily rest during the day.
Volunteers under 60 who used to nap had a 20% higher risk of developing high blood pressure than their peers who never sleep outside the nighttime hours. A risk that, curiously, dropped to 10% for people over 60. Really all the fault of the afternoon nap? Not exactly.
It’s the night’s sleep that’s responsible
Don’t panic: it’s not the afternoon rest that’s dangerous in itself, but it’s a combination of guilt. Indeed, the study reveals that it is Lor poor night’s sleep to increase the risk factor of hypertension and stroke. In fact, many people take an afternoon nap to make up for the few hours of sleep at night or in any case for the poor quality of it. We have known for a long time that sleep badly at night can lead to health problems and naps are not sufficient to offset the effects, nor can they serve as a replacement. This is also confirmed by Michael Grandner, director of the sleep and health research program at the University of Arizona.
The data of the study – obtained by crossing both the personal observations of the participants and using the Mendelian randomisation (RM) method – are clear in this regard: they found that many participants suffered from insomnia or sleep apnea, snored, had a habit of smoking cigarettes and drinking alcohol frequently. So bad sleep during the night goes hand in hand with daily naps and if the latter are accompanied by bad habits, well, les jeux sont faits.
So, is the daily nap good or bad?
So, long story short: the afternoon nap is good or bad? A yes or no is not enough to answer the fateful question. In itself it doesn’t hurt, but it doesn’t have to be accompanied by night sleep disturbances. If the half hour of sleep after lunch creates insomnia, makes us go to bed later or causes more awakenings during the night, it is important to learn to avoid it in order not to suffer health consequences. Any sleep disorder needs to be investigated ASAP because it’s linked to increased perceived stress, then hormones that can lead to obesity, type 2 diabetes, high blood pressure and heart disease.
However, the experts are clear: more in-depth studies will be needed to better understand what the real impact of napping is on the incidence of hypertension and stroke because, in the meantime, other studies have convinced us of its positive impact on our health. Among many others, the research conducted by the University of Colorado has shown that sleeping 15 – 20 minutes in the day already forwarded helps improve memory, productivity and self-awareness. That’s not all: Berkeley researchers have discovered that adults who regularly use the afternoon to rest a bit also have a greater learning capacity.
In short, as always, it is difficult to navigate between contradictory research, but there is one thing we can do to make sure we don’t make a mistake: try to have a good night’s sleep.