The people who only need five hours’ sleep

Alana Rush, 40, a technology adviser from Dublin, goes to bed at 1.30am and wakes up around 6am. “Today I left the house at 4.45am to hand out sandwiches to homeless people,” she says. “I’ve always felt a bit different to most people. I get a real burst of energy and creativity in the evening, but I also love to watch the sunrise and get out early and start the day. My friends think I’m mad and joke that I’m like Hermione Granger with a ‘time turner’, because I can get so much done in 24 hours.”

What is a short sleeper?

We used to think people could be divided into two chronotypes: “morning larks”, who naturally wake up early, raring to go, and “night owls”, who love to stay up late burning the midnight oil. But now a study has found that a select group of people might be both. And for these “super sleepers”, the idea that we all need eight hours of sleep a night to perform at our best is a myth.

Louis Ptáček is a neurologist at the University of California, San Francisco. With his colleague, Ying-Hui Fu, a human geneticist and neuroscientist, they have identified seven specific genes that make some people natural “short sleepers” – those who need only four to six hours of slumber a night and suffer no health consequences. In fact, they might be healthier than the rest of us.

“This all started in the mid-Nineties with a woman who came to me complaining of being an extreme morning lark,” says Ptáček, from his office in San Francisco. “She would always wake up in the wee small hours when it was cold, lonely and dark. She also told me that there was a genetic history of it in her family, and her granddaughters were the same, so I wondered if we could isolate that gene and clone it.”

The science behind it

Ptáček and Fu were able to pinpoint that the woman and her family had a genetic mutation, and when they published their findings, thousands of short-sleeping families offered themselves up for research. Fu and Ptáček were able to trace the trait for not needing much sleep to various mutated genes.

One was a mutation in a gene called DEC2. “One of this gene’s jobs is to control levels of a brain hormone called orexin, which promotes wakefulness,” says Ptáček. “At the other end of the spectrum to short sleepers are people who can’t produce enough orexin, who suffer from narcolepsy.”

When they genetically engineered these gene mutations into mice, they found that these rodents needed less sleep than their littermates, yet suffered no health consequences. In behavioural tests, the mice lacked the memory problems that typically follow a short night’s sleep.

And even more astonishingly, they found that having the short sleep gene might protect you from certain diseases. “When we cross-bred mice that had short sleep genes with mice that carried genes predisposing them to Alzheimer’s, that was really quite interesting,” says Ptáček. “The Alzheimer’s mice developed a build-up of abnormal proteins – amyloid plaques and tau tangles – that, in humans, are hallmarks of dementia. But the brains of the hybrid mice developed fewer of these tangles and plaques, as if the sleep mutations were protecting them. Of course, it doesn’t prove that short sleepers are less likely to get Alzheimer’s – we would need to study thousands of people – but these genetic mutations do seem to be protective in some way.”

Short sleepers aren’t just able to function on a small amount of rest, they actually excel. “Anecdotally, we’ve found that these types of people are really remarkable,” says Ptáček. “They’re go-getters, they’re ambitious, energetic and optimistic, with remarkable resilience against stress and higher thresholds for pain. They seem to be healthier than average and might even live longer.”

Life on less sleep

Although it might seem like a superpower for productivity, being a short sleeper can have its drawbacks. Guy Thompson, 42, is a production designer from London who needs only five hours’ sleep a night. “I go to bed around 11pm and wake up around 4am,” he says. “I’ll often stay in bed with a cup of tea and read the news. Sometimes I’ll try to rest and daydream or read a book. It’s nice to have time to myself, but it’s normally still dark and my partner and my four-year-old daughter don’t get up until at least 8am, so it can feel quite lonely.”

Alana Rush says her love of late nights and early mornings can make holidays with friends tricky. “I’m the last one in the bar at night and also the first one up to go sightseeing,” she says. “I find I have two sets of friends, those who I can stay up late with and those who want to go for coffee early.”

Although the average person sleeps for a third of their lives, we still know remarkably little about what is really happening to our brains and bodies while we’re in the land of nod. It is thought that we are replenishing energy stores, flushing waste and toxins, and consolidating memories. What we do know is that getting less sleep than you need can have serious health consequences, including memory problems, metabolic issues, depression, dementia, heart disease, and a weakened immune system.

So are these “super sleepers” just resting more efficiently? Are they getting more deep “slow-wave” sleep – thought to be the most restorative sleep stage? “It’s all about efficiency, sleep efficiency, that’s how I feel,” says Fu. “Whatever these people’s bodies need to do with sleep, they can get it done in a short time.”

Interestingly, Rush says that in her 20s she was worried about the fact that she was sleeping only four hours a night and asked to be monitored in a sleep study. The researchers found that she went into REM sleep very quickly – in a matter of seconds – whereas it would take most people 30-60 minutes or more.

Can anyone become a short sleeper?

It’s thought that just 1 to 2 per cent of the population are “short sleepers”, but it’s unlikely that the rest of us all need a solid seven-to-nine hours straight every night. Studies have shown that women generally need more sleep than men, and teenagers and children generally need more sleep than adults, as their brains and bodies are still developing.

“Not everyone needs to sleep for eight hours in a solid block,” says Nick Littlehales, a sleep coach who works with elite athletes including the footballer Cristiano Ronaldo. “I think this dramatic increase in sleep awareness and sleep trackers has actually made people’s sleep worse. With my clients I try to think about sleep in 90-minute cycles, and most people need about four to six of those every 24 hours.”

Indeed, in the Middle Ages, people typically slept in two shifts and would go to bed for a couple of hours, wake up to socialise, pray and study – in a period called “the watch” – and then return to bed for a few more hours.

Throughout history, many successful high achievers have debunked the idea that we all need eight hours’ kip to perform well. Margaret Thatcher claimed to sleep only for four hours a night, as did Thomas Edison, who called sleep a waste of time – “a heritage from our cave days”. His invention of the electric lightbulb changed sleep patterns for everyone.

Yet short sleepers and successful people seem inextricably linked, whether that’s due to the personality traits associated with their genes, or just the fact that they have more hours in the day than the rest of us. Inventor Nikola Tesla claimed to never sleep for more than two hours a day. He once reportedly worked for 84 hours straight in a lab without any rest. Martha Stewart, the American television personality, says she wakes up at 4am or 5am every day.

Would all these people be genetic short sleepers? “It’s impossible to say for certain but it seems likely,” says Ptáček. “There are natural short sleepers and then there are what we call ‘facultative short sleepers’. These are type-A high achievers who sleep less than average, not because of a genetic difference, but because their drive compels them to get less sleep than they’d like. What’s interesting with natural short sleepers is if you try to make them sleep longer they report feeling worse.”

Many trailblazing figures have taken an unusual approach to sleep. Leonardo da Vinci had a 20-minute nap every four hours rather than sleeping every night. Winston Churchill took a two-hour nap at 5pm each day, and claimed this enabled him to work one and a half days every 24 hours, as he worked late into the night and even held war Cabinet meetings while he was in the bath. US presidents Lyndon B Johnson and John F Kennedy swore by daily naps to break the day into two shifts.

So if you’re the type of person who can’t function on less than eight hours’ rest, is there a way to become a super sleeper? “We don’t know yet,” says Ptáček. “But by identifying this gene, we’re a bit closer to understanding what sleep is and how we can help the millions of people with chronic sleep problems, and all those who want to sleep better or more efficiently.”

Could there be a future in which tech companies implant the short-sleeping gene into their employees to increase productivity? “If you could take a pill to sleep less each day and still feel great, then I’d be really excited to try that,” says Ptáček. “And I think a lot of other people would be too.”