School children who nap are happier, excel academically, and have fewer behavioral problems
May 31, 2019
Science Daily/University of Pennsylvania
Children who nap 30 to 60 minutes midday at least three times a week are happier, have more self-control and grit, and showcase fewer behavioral problems, according to new research. These children also have higher IQs and excel academically.
Ask just about any parent whether napping has benefits and you'll likely hear a resounding "yes," particularly for the child's mood, energy levels, and school performance. New research from the University of Pennsylvania and the University of California, Irvine, published in the journal SLEEP backs up that parental insight.
A study of nearly 3,000 fourth, fifth, and sixth graders ages 10-12 revealed a connection between midday napping and greater happiness, self-control, and grit; fewer behavioral problems; and higher IQ, the latter particularly for the sixth graders. The most robust findings were associated with academic achievement, says Penn neurocriminologist Adrian Raine, a co-author on the paper.
"Children who napped three or more times per week benefit from a 7.6% increase in academic performance in Grade 6," he says. "How many kids at school would not want their scores to go up by 7.6 points out of 100?"
Sleep deficiency and daytime drowsiness are surprisingly widespread, with drowsiness affecting up to 20% of all children, says lead author on the study Jianghong Liu, a Penn associate professor of nursing and public health. What's more, the negative cognitive, emotional, and physical effects of poor sleep habits are well-established, and yet most previous research has focused on preschool age and younger.
That's partially because in places like the United States, napping stops altogether as children get older. In China, however, the practice is embedded into daily life, continuing through elementary and middle school, even into adulthood. So, Liu and Raine, with Penn biostatistician Rui Feng, UC Irvine sleep researcher Sara Mednick and others, turned to the China Jintan Cohort Study, established in 2004 to follow participants from toddlerhood through adolescence.
From each of 2,928 children, the researchers collected data about napping frequency and duration once the children hit Grades 4 through 6, as well as outcome data when they reached Grade 6, including psychological measures like grit and happiness and physical measures such as body mass index and glucose levels. They also asked teachers to provide behavioral and academic information about each student. They then analyzed associations between each outcome and napping, adjusting for sex, grade, school location, parental education, and nightly time in bed.
It was the first comprehensive study of its kind, Mednick says. "Many lab studies across all ages have demonstrated that naps can show the same magnitude of improvement as a full night of sleep on discrete cognitive tasks. Here, we had the chance to ask real-world, adolescent schoolchildren questions across a wide range of behavioral, academic, social, and physiological measures."
Predictably, she adds, "the more students sleep during the day, the greater the benefit of naps on many of these measures."
Though the findings are correlational, the researchers say they may offer an alternative to the outcry from pediatricians and public health officials for later school start times. "The midday nap is easily implemented, and it costs nothing," says Liu, particularly if accompanied by a slightly later end to the day, to avoid cutting into educational time. "Not only will this help the kids, but it also takes away time for screen use, which is related to a lot of mixed outcomes."
Future directions could look at why, for example, children with better-educated parents nap more than children with less educated parents, or whether, by investigating the influence of culture and personality, nap interventions could be advanced on a global scale. Ideally, a randomized control trial would get at causation questions like whether napping leads to better academic achievement or whether they're linked in some other way. However, none of this is yet in the works.
For now, the researchers say they hope the results of this current study can inform future interventional work that targets adolescent sleepiness.
https://www.sciencedaily.com/releases/2019/05/190531135828.htm
Midday naps associated with reduced blood pressure and fewer medications
August 29, 2015
Science Daily/European Society of Cardiology
Midday naps are associated with reduced blood pressure levels and prescription of fewer antihypertensive medications, according to new research.
"Although William Blake affirms that it is better to think in the morning, act at noon, eat in the evening and sleep at night, noon sleep seems to have beneficial effects," said Dr Kallistratos. "Two influential UK Prime Ministers were supporters of the midday nap. Winston Churchill said that we must sleep sometime between lunch and dinner while Margaret Thatcher didn't want to be disturbed at around 3:00 pm. According to our study they were right because midday naps seem to lower blood pressure levels and may probably also decrease the number of required antihypertensive medications."
He added: "Μidday sleep is a habit that nowadays is almost a privileged due to a nine to five working culture and intense daily routine. However the real question regarding this habit is: is it only a custom or is it also beneficial?"
The purpose of this prospective study was to assess the effect of midday sleep on blood pressure (BP) levels in hypertensive patients. The study included 386 middle aged patients (200 men and 186 women, average age 61.4 years) with arterial hypertension. The following measurements were performed in all patients: midday sleep time (in minutes), office BP, 24 hour ambulatory BP, pulse wave velocity, lifestyle habits, body mass index (BMI) and a complete echocardiographic evaluation including left atrial size. BP measurements were reported as diastolic and systolic BP.
After adjusting for other factors that could influence BP such as age, gender, BMI, smoking status, salt, alcohol, exercise and coffee, the researchers found that midday sleepers had 5% lower average 24 hour ambulatory systolic BP (6 mmHg) compared to patients who did not sleep at all midday. Their average systolic BP readings were 4% lower when they were awake (5 mmHg) and 6% lower while they slept at night (7 mmHg) than non-midday sleepers.
Dr Kallistratos said: "Although the mean BP decrease seems low, it has to be mentioned that reductions as small as 2 mmHg in systolic blood pressure can reduce the risk of cardiovascular events by up to 10%."
The researchers also found that in midday sleepers pulse wave velocity levels were 11% lower and left atrium diameter was 5% smaller. "These findings suggest that midday sleepers have less damage from high blood pressure in their arteries and heart," said Dr Kallistratos.
The duration of midday sleep was associated with the burden of arterial hypertension. Patients who slept for 60 minutes midday had 4 mmHg lower average 24 hour systolic BP readings and a 2% higher dipping status5 compared to patients who did not sleep midday. Dippers had an average of 17 minutes more midday sleep than non-dippers.
Dr Kallistratos said: "Our study shows that not only is midday sleep associated with lower blood pressure, but longer sleeps are even more beneficial. Midday sleepers had greater dips in blood pressure while sleeping at night which is associated with better health outcomes. We also found that hypertensive patients who slept at noon were under fewer antihypertensive medications compared to those who didn't sleep midday."
He concluded: "We found that midday sleep is associated with lower 24 hour blood pressure, an enhanced fall of BP in night, and less damage to the arteries and the heart. The longer the midday sleep, the lower the systolic BP levels and probably fewer drugs needed to lower BP."
https://www.sciencedaily.com/releases/2015/08/150829123659.htm