The perfect power nap? Low and not in bed, find Spanish study

Are naps a secret weapon to improve health? The question has provoked conflicting opinions among scientists for decades, but one thing is certain: the midday nap affects how our bodies function.

In a recent study published in the scientific journal Obesity, a team of Spanish scientists delved into the question of napping. Their findings shed new light on the connection between nap duration and location and various metabolic markers, including obesity.

The study was carried out with more than 3,000 Spaniards from Murcia.

It found that those who took long naps — more than 30 minutes — had a 2 percent higher body mass index, a measure of body weight relative to height, than those who didn’t sleep.

They also had a 23 percent increased risk of obesity and a 40 percent increased risk of metabolic syndrome, a group of medical conditions that increase the risk of developing cardiovascular disease.

On the other hand, people who took short naps, less than 30 minutes, had a 21 percent lower risk of high blood pressure.

“Long naps are associated with increased metabolic syndrome body mass index, triglycerides, glucose, and blood pressure,” said Marta Garaulet, study author and professor of physiology at the University of Murcia, Spain.

“On the other hand, when the nap is short, we see it associated with a decrease in the probability of having high blood pressure, so, in a way, the nap becomes protective.”

The study concluded that the duration of the nap should be considered as “relevant in obesity”, but the results only point to “associations”, Garaulet clarifies, and not to a formal cause and effect.

In other words, researchers have made “relevant” associations between people who, for example, take long naps and are at increased risk of obesity, but that doesn’t necessarily mean these people are overweight because they’re taking long naps. Nor that they are taking long naps due to their weight.

culture and siesta

Last year, Garaulet led another study at the UK Biobank involving 450,000 people and found 127 genetic variants associated with napping: “the higher napping genetics, the higher nap frequency,” Garaulet told Euronews Next, “what that would help explain why some people are unable to nap.”

the study of english – unlike the Spanish study – used a statistical technique used in genetic research to investigate causal relationships between risk factors and health outcomes called Mendelian randomization. The technique allowed Garaulet’s team to pinpoint “potential causal links between more frequent daytime naps and higher blood pressure and waist circumference.”

The Spanish findings are less conclusive because they did not use the statistical technique. However, they offer new insights into napping.

The British study was carried out in a population with a median age of 60 years “and where napping is not a habit of that culture,” said the Spanish scientist. So he was curious to see what would happen in a sample of younger people with fewer illnesses, but also in a country where there is a strong siesta culture and hot temperatures.

The heat was relevant because previous studies have shown that nap genes are activated by heat.

“Summer temperatures activate the PER3 gene, which is the clock, the gene that initiates the siesta,” says Garaulet, which would explain why in the Mediterranean there is a greater tendency to take a siesta at noon than in the Nordic countries.

Some people don’t have the nap genetics, he explained, “however, if you do, then this nap gene could be turned on in warmer areas and you’ll feel like sleeping during the day.”

The Spanish conclusions refined those obtained from the English bank, and Garaulet was not only able to evaluate the finer aspects of daytime sleep episodes -in particular, how the duration of the nap influenced the health of the subjects evaluated- but also that the people asleep influenced the health benefits.

“There is a positive association between short naps and improved blood pressure, especially if you sleep in an armchair or on the couch, not in bed,” Garaulet said.

It seems that humans are not meant to have major postural changes throughout the day, as this can increase blood pressure, he explained.

In line with her findings linking obesity to long naps, Garaulet, a visiting professor at Harvard, recently published another study that concluded that people who take long naps are more likely to have a disturbed rhythm in an enzyme called lipase, which plays a role in a crucial role in the digestion and metabolism of dietary fats.

Naps make better workers

Garaulet said that understanding the science behind naps could help recommend new methodologies to improve employee performance.

Previous studies have found that short naps are associated with improved working memory, as well as improved performance and alertness, especially in sleep-deprived subjects, but the long-term effects of regular naps on chronic disease risk remain. being controversial.

“That’s why it’s a topic of interest, it will help to see whether or not napping is recommended to get all these benefits at work,” Garaulet said, “but more research is needed.”

To achieve conclusive results regarding the metabolic effects of napping, scientists need to conduct randomized crossover studies, Garaulet added, which involves conducting experiments in which the same people are put to nap but also refrain from napping.

“The problem with these studies is that they can only be done in the short term, so it’s possible to look at the acute effects of napping, but not its effect on overall health.”

Acute effects refer to short-term changes or responses observed after a specific intervention or exposure, such as memory enhancement from short naps.

To draw conclusions about metabolic risk or obesity, researchers need many months with the same subjects, “and you can’t put a person who never naps or doesn’t have the genetics to nap to sleep every day or that (have) those who take a nap, that they do not sleep for six months,” he said.

But while conducting randomized crossover studies can be challenging, previous long-term studies have provided evidence of the benefits of naps for our health. In 2007, a study conducted by the Harvard School of Public Health suggested that naps contributed to the lower rates of heart disease seen in Mediterranean countries.

The study followed more than 23,000 people for six years and showed that regular naps can reduce deaths from heart disease by up to 37 percent, providing a benefit on the same order of magnitude as that associated with lowering cholesterol, eating a healthy diet, or exercising.

Modern lifestyles have significantly influenced the frequency, duration, and timing of sleep episodes, and while research on napping may not provide conclusive evidence, there is an overwhelming body of scientific literature supporting the idea that nothing it is most vital to our health, happiness and well-being. and productivity than a good night’s sleep.