Is it true that there are people who only need a few hours of sleep a night? BBC Future spoke to a woman whose genes may be able to give us clues on how to spend less time in bed.
What would you do if you suddenly had 60 extra days a year at your disposal? You can ask Abby Ross, a former psychologist from Miami, Florida, about this. She sleeps a little: she needs only four hours of sleep a day, so she has a lot of free time, gained from the hours that other people spend in bed.
“It's great to have so many hours in a day: I feel like I can live two lives at once,” she says.
Low-sleep people like Ross never feel overwhelmed and do not like to roll in bed. They get up early - usually at four or five in the morning - and enthusiastically get to work. Perhaps one of them was the "Iron Lady", former British Prime Minister Margaret Thatcher: she said she sleeps four hours a day. While singer Mariah Carey assures that she needs at least 15 hours.
How is it that some of us sleep quite effectively, while others doze for half a day before more or less completely awake? And is it possible to change your biorhythm in such a way as to get enough sleep more productively?
People with the DEC2 gene mutation simply sleep more efficiently than everyone else
In 2009, a woman came to the laboratory at the University of California, San Francisco, where Dr. Yin-Hui Fu conducts sleep research, complained that she always woke up too early. At first, Fu decided that this patient was just a pronounced "lark," that is, a person who goes to bed early and gets up early.
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But the woman explained that she actually goes to bed around midnight and wakes up at four in the morning completely refreshed. Several other members of her family did the same, she said.
Fu and colleagues compared the genome of different members of this family. They found a small mutation in a gene called DEC2, which was present in all low-sleepers. Other relatives did not have it, as did the 250 volunteers recruited from outside.
When scientists bred mice with a similar gene mutation, it turned out that these rodents also slept less than their counterparts, but at the same time successfully performed physical and mental tasks.
Typically, sleep deprivation has a very significant impact on overall health, quality of life, and life expectancy. It can lead to depression, obesity, and increase the risk of heart attack and diabetes. “Sleep is very important: if you sleep well, you can avoid many diseases and even dementia,” says Fu. "If you deprive a person of just two hours of sleep a day, it almost immediately negatively affects his thinking ability."
But why sleep is so important for the human body, scientists still cannot fully understand. They generally agree that the brain needs sleep to tidy itself up and accomplish important tasks that lack resources while awake. During sleep, the brain can heal damaged cells, remove toxic substances accumulated during the day, replenish energy reserves and fix the information received in memory.
“Obviously, people with a DEC2 gene mutation can perform all the same tasks in a shorter time - they simply sleep more efficiently than everyone else,” says Fu. - But how do they do it? This is really the main question."
Little ones in the morning have a lot of free time that can be used for anything
According to the scientist, since the discovery of the DEC2 mutation, many people have already stated that they can only sleep a few hours a day. Most of these patients have insomnia. “We didn’t undertake to study those who have sleep problems, and they sleep less because of it. We decided to focus our efforts on those who sleep for several hours and still feel great,”explains the researcher.
Among people who do not sleep well, studied in the Yin-Hui Fu laboratory, a positive attitude towards life prevails. “From the conversations it becomes clear that they are very energetic and optimistic. They often feel like they want to get the most out of their lives, but we can't say with certainty if this has anything to do with their mutations,”she says.
Abby Ross fits this character well. “I always feel great when I wake up,” she says. She sleeps four to five hours a day for as long as she can remember.
“These first hours of the morning - around 5 am - are amazing. Everything is quiet and peaceful and there is so much to do. It would be great if more stores were open at this time, but I can shop online or read: there is so much interesting reading! You can also go and work out while everyone is asleep, or chat with people living in other time zones,”says Ross.
The most effective way to improve sleep is to get up at the same time every morning.
Less sleep allowed her to complete her university course in two and a half years, as well as acquire many new skills. For example, just three weeks after the birth of her first son, Ross decided to use the early morning for a run. She ran the block in 10 minutes. The next day she went out for a run again, this time further away.
She gradually increased the training time until she ran 37 marathons (one per month for three years) and several ultramarathons (an ultramarathon is called any race over a distance longer than the traditional 42.195 km - Ed.).
“I can get up before everyone else and work out - and that's it, I no longer need to think about it,” she says.
As a child, Ross spent the morning hours with her father, who also slept little. “In the morning we had such a great time together!” She recalls. Now, if she suddenly sleeps longer than usual (which, she says, has only happened a few times), her husband starts to worry if she’s dead: “I’m not lying in bed, it would make me feel terrible.”
Useful advice
Dr. Yin-Hui Fu subsequently sequenced the genomes of several more families that met the criteria for low sleep. Scientists are just beginning to figure out what gene mutations give a person such an ability, but, according to Fu, it is possible that one day we will be able to "turn on" it artificially.
But until that happens, are there any helpful tips to help us sleep more effectively? Neil Stanley, an independent sleep consultant, says yes: "The most effective way to improve sleep is to get up at the same time every morning."
When the body gets used to a certain wake-up time, Stanley said, it makes the most of the remaining sleep time until that hour. “Research shows that the body begins to prepare to wake up about an hour and a half before waking up. The body really likes the regularity, and if you constantly change your sleep time, then the body has no idea whether to prepare for the rise."
In addition, the specialist notes, you should not listen to public opinion about sleep. “It is generally accepted in society that not enough sleep is a good trait and should be encouraged. We are constantly cited as examples of Margaret Thatcher and famous business leaders who don't need a lot of sleep. But in fact, all this is determined genetically, like the height and size of the shoe. Some people need little sleep, while others need 11 or 12 hours to get into the optimal mode."
According to Stanley, many of those who have sleep problems don't actually have trouble falling asleep, but simply have their own expectations about how much sleep they need. “If each of us could identify our sleep needs and live accordingly, our quality of life would be greatly improved,” he concludes.