Why are there people who sleep a few hours a night and function the same (or better) than others

How many hours of sleep a night does a human need to be healthy? I bet you answered eight hours, but that’s not entirely true, according to recent scientific findings.

“This is a misunderstanding. It’s like saying that everyone should be 1.65 m tall and that if you’re shorter than that, you have a problem”, tells the BBC Louis Ptacek, a researcher at the Department of Neurology. from the University of California, United States.

Not all of us need the same amount of sleep to feel rested and get on with the day. And it’s not a matter of behavior or personal choice. It’s in the genes.

Some people are genetically engineered to naturally get little sleep. This means that even with just 4 to 6 hours of sleep a night, they wake up refreshed.

“These people function on a lot less sleep and they do it with high performance. That’s an advantage in the working world we live in,” says Ptacek.

morning larks vs night owls

Over the past 25 years, Ptacek and his team have analyzed the sleep patterns of more than 100 families. “In the beginning, all of our work was focused on what should be the criteria for calling someone a ‘deep sleeper’.”

A person in an advanced stage of sleep is also called a morning lark – someone who goes to bed early and wakes up early.

“There were people who caught our eye. Although they were ‘morning larks’ and they were up early, they stayed up late to be part of our criteria. It was clear then that there were families that were morning larks but also night owls,” says Ptacek.

The existence of these people who were able to sleep for a few hours made the team from the Department of Neurology at the University of California understand that they were facing a very different type of condition.

They were people with “natural short sleep”, which allows them to wake up early but also go to bed late. So far, four genes have been linked to “natural short sleep,” but there may be more. The challenge is that these genes are very rare.

Ptacek estimates that one person in a thousand belongs to this group of “elite sleepers”. The good news is that these genes can help unlock the secrets of efficient sleep.

Using sleeper genes efficiently

Studies carried out by Ptacek’s team revealed that those people who get little sleep have a much greater capacity for adaptation than others.

“We have a strong impression that these people are healthier than average,” says the researcher. “They sleep a lot less and are still very functional, so maybe they’re sleeping more efficiently. The question is what that means.”

We may be closer to the answer to this question. In a new study, genes associated with “natural short sleep” were introduced into mice with Alzheimer’s disease. And the animals became more resilient.

“This is very interesting because it suggests that we can use this biological knowledge for therapeutic purposes, not only in relation to neurodegenerative diseases, but also psychiatric diseases, diabetes, obesity, many types of cancer,” says Ptacek.

For the doctor, studying the dream is like a big puzzle of which we still don’t have the definitive image:

“We are still in the discovery process, trying to find as many pieces of the puzzle as possible. What we have are these families, and in each family we can identify a gene and a genetic variant, and show that these genes are behind those standards.”

For something most of us spend a third of our lives doing, there’s still a lot to understand when it comes to sleep.

“Something happens when we sleep that allows us to restore our function and wake up the next day and work well. If we can do this better, understanding how sleep efficiency is regulated, this could have a huge impact on human health.”

This text was originally published here.