Reason why you like to nap could be down to your genes, study suggests

Olivia Petter
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Do you enjoy taking a quick power nap every now and then? Or have you never understood the concept?

The advantages of napping are well-documented, with studies hailing the benefits for concentration levels and overall alertness, but some people feel the benefits more than others.

Now, there might be a scientific explanation as to why this is.

A new study on mice conducted at the University of Tsukuba in Japan reveals that a single gene mutation may increase the amount of sleep that a mouse needs, a revelation which researchers think may provide useful insight into human sleeping habits.

Published in the journal Proceedings of the National Academy of Sciences, the study notes that little is known about the physiological mechanisms that regulate sleep.

This means that the reasons why one person’s sleeping pattern differs from another has remained somewhat of a mystery, until now.

For this study, the authors built on previous research into the mutation of a protein called SIK3 and examined the effects this had on the sleeping habits of mice.

In addition to noting down how long the mice slept for and how long they were awake for, the researchers looked into their brain activity during periods of dreaming and non-dreaming sleep, and levels of alertness during awake periods.

They found that by mutating the 551st amino acid in SIK3, the mice subsequently needed more sleep and slept for longer, something that was reflected in their brainwave activity.

The mice were also awake for less time than usual during the night, which is when they are normally most active.

“The findings were particularly interesting in that this mutation affected the periods of sleep lacking rapid-eye-movement, the largely non-dreaming part of sleep, while rapid-eye-movement sleep was largely unchanged," said co-author Masashi Yanagisawa.

"This showed that SIK3 is involved in very specific sleep-related regulatory mechanisms."

Lead author Takoto Honda added that the features of this particular amino acid in this protein are similar across the animal kingdom, meaning that the findings are relevant to humans and could benefit ongoing research into human sleep disorders.

"For example, in the condition idiopathic hypersomnia, patients experience a strong need to sleep and are sleepy during the day, like the mice in our study. Our work could help to explain why," he said.

This may imply that people who need to sleep more - something they may resolve by napping - could have a mutated version of the same protein examined in the research.

However, given that the study was conducted on mice and not humans, there is no way to be certain.

Nonetheless, the findings could be groundbreaking, considering that in the US, one in three adults don’t get enough sleep, according to the Centers for Disease Control and Prevention, which it defines as seven hours a night.

Comparatively, in the UK, according to the latest report by the Sleep Council, almost three-quarters of people are getting less shut-eye than this.

Sleeping less than seven hours a night is associated with an increased risk of developing conditions such as obesity, diabetes, high blood pressure, heart disease, stroke, and frequent mental distress, the CDC states.

Hence the appeal of napping, which many of us resort to in order to make up for lost time.

However, in order to fully reap the benefits of a nap, you may need to re-jig your work schedule, as one study claims the optimum nap time is 3pm.

Any later than that and you may struggle to sleep in the evening, causing disruption to your circadian rhythm, which could pose even more problems in the long run.