The False Dream of Less Sleep

Unless you’ve got a very rare “short sleep” gene, you need seven hours — every day

During a typical week in college, I slept four or five hours a night. Between evening classes, club meetings, and writing lab reports, I was lucky if I made it to bed by midnight before my 5 a.m. alarm wailed each morning for rowing practice.

I never actually felt too terribly tired, which was the strange part. Naturally, I likened myself to Winston Churchill, Thomas Edison, Nikola Tesla, and other greats who claimed to need just a few hours of sleep each night. Little did I know, the damage was already being done.

It wasn’t until I started researching sleep for my PhD in neuroscience that I realized only a handful of people actually succeed at getting by on just a few hours of rest — and they’ve got genetics on their side.

According to a recent study by the Centers for Disease Control and Prevention, more than one-third of American adults report sleeping less than seven hours each night, which is the minimum duration recommended for optimal health by sleep researchers and physicians. If that’s all we can manage, then what can we do about it? Break our hours of sleep into smaller, compressed chunks?

In a meta-analysis of 1.4 million individuals, those who regularly slept less than seven hours per night had a 12 percent increased risk of death

It’s an appealing notion first popularized by Italian chronobiologist Dr. Claudio Stampi. In 1992, Stampi claimed that “polyphasic sleep,” the practice of sleeping multiple times within a 24-hour period, is better than snoozing all at once. Historians believe — and followers of the polyphasic sleep movement often cite — that before the dawn of electric lighting in Europe many people used to operate on two shorter sleep periods each day. Polyphasic patterns are also common in many mammals — for example, just think of your pug Chubs.

Unlike Chubs, however, your polyphasic sleep periods don’t stretch into luxurious 20-hour dates with your pillow.

In fact, the Uberman schedule — the most extreme of the bunch — boasts just two hours of sleep each day. In the late 1990s, two college philosophy students inspired by Friedrich Nietzsche’s notion of the super-human Übermensch decided to give it a go. Frustrated by regular bouts of insomnia, they began experimenting with four half-hour nap periods a day, impressing their classmates with their extreme productivity and seemingly perfect work-life balance.

Nietzsche’s 1883 book “Thus Spoke Zarathustra” introduced the Übermensch (“Overman” or “Uberman”) as the ultimate goal for humanity after his famous pronouncement that “God is dead.” Zarathustra, the fictional narrator of this philosophical text, says: “The overman is the meaning of the earth. Let your will say: The overman shall be the meaning of the earth! I appeal to you, my brothers, remain true to the earth, and do not believe those who speak to you of otherworldly hopes!” Without God, humans are no longer bound by the arbitrary morals of divinity. By maximizing his own potential through self-cultivation, the Übermensch is free to create meaning and achieve his ideal life.

A WWII poster by the controversial U.S. Office of War Information ties sleep to productivity

In the same vein, followers of the Uberman sleep schedule reject societal norms in an effort to enrich their own lives — maximizing productivity and play while reducing what’s seen as wasted hours spent lifelessly in bed.

Today, the Polyphasic Society website has a section devoted to teaching members how to “repartition” their sleep stages, dream lucidly, and even learn calculus or Shakespeare while sleeping. The subreddit r/polyphasic on Reddit.com has more than 2,300 followers, with messages ranging from “How does this schedule sound?” to “Is this actually okay to do?”

In a typical night, we experience four stages of sleep, and each cycle lasts around 90 minutes before repeating itself again. The first stage is that light, drowsy phase we slip into just as we’re falling asleep. In the second stage, we become unconscious of our surroundings. Slow-wave, or “deep,” sleep is a particularly restorative phase (associated with recovery after sleep deprivation, memory consolidation, and reduced levels of inflammation and stress hormones). We dream during rapid-eye-movement (REM) sleep, when our skeletal muscles are paralyzed, yet our eyes flutter rapidly.

The key to polyphasic sleep, the society’s website claims, is that the body prioritizes REM over the other sleep stages. When we only allow ourselves to sleep for short chunks of time, our brain learns to rearrange our sleep patterns and fill our short naps primarily with REM.

This change, of course, assumes two things — first, that REM is the only important stage of sleep; and second, that immediately entering REM is a good thing.

In reality, it’s a bit more like our body hitting the panic button.

In an elaborate 2008 study, Daniel Mollicone and colleagues assigned participants to one of 18 different sleep regimens. Each pattern differed in terms of total sleep (between four and eight hours) and the timing of sleep, with various combinations of daytime and nighttime naps. After 10 days — when participants were tested on reaction time, behavioral alertness, and cognitive accuracy — the sleep-deprived subjects performed significantly worse than those who were more rested — in other words, the sleep schedule itself did not play a role in performance.

The craziest part of sleep deprivation is that, after a while, we don’t realize that we’re sleepy. In 2003, Hans Van Dongen and colleagues reported that after two weeks of sleep deprivation (four or six hours of sleep per night), participants showed significant lapses in alertness. Subjectively, though, sleep-deprived subjects did not report feeling much drowsier than those who had eight hours in bed each night.

The key, then, is getting enough sleep. Below that optimal seven or eight hours per night, our brains (and bodies) begin to suffer no matter which sleep pattern we choose.

And the complications following sleep deprivation are seemingly endless. Just one all-nighter alters your immune system. Sleep loss also affects everything from growth to body temperature. Just a week of mild sleep restriction significantly increases inflammation. A 2013 study reported that the transcription of as many as 700 genes is altered after one week of six hours of sleep per night. Memory, decision-making, and attention are significantly reduced with chronic sleep loss, and even weekend recovery sleep was shown to be insufficient in reserving attentional deficits that built up over the workweek. In a meta-analysis of 1.4 million individuals, those who regularly slept less than seven hours per night even had a 12 percent increased risk of death.

Biopsychosocial model of sleep duration drivers/ © 2015 Associated Professional Sleep Societies, LLC

So the science trumps the Uberman. In fact, adopting such a highly restrictive sleep schedule in an attempt to achieve a fulfilling, productive life is almost the antithesis of the Übermensch, as it’s so fundamentally bad for you. Can a person truly cultivate an ideal life while sacrificing health and well-being at the same time?

A natural short sleeper may have the upper hand, in this case. About 1 percent of the population can get by on as little as four or five hours of sleep per night and feel perfectly refreshed. And such people are mutants — literally.

In the early 2000s, geneticist Ying-Hui Fu was studying familial advanced sleep-phase syndrome, a condition in which individuals sleep for normal durations but go to bed and wake up significantly earlier than most people. After identifying a mutation (a DNA alteration) in a gene related to the condition, people with self-described “unusual sleep schedules” began coming forward and providing DNA samples to the research team. One subject, a woman in her 90s, had so much energy after just a few hours of sleep that she felt compelled to volunteer at a prison to pass the time.

In the mid-2000s, Fu and colleagues identified a mutation in DEC2, a gene that codes for a circadian rhythm protein, in a mother and daughter who slept just six hours each night. To further study this mutation, Fu engineered mice that carried mutated DEC2 in their genome. Indeed, these mice slept about an hour shorter than normal mice.

Another study, published in 2014, studied pairs of twins and identified a mutation in a different region of the same gene. One twin slept an hour shorter on average than his brother. When restricted to four hours of sleep per night, the man with the DEC2 mutation performed significantly better than his brother on a cognitive task, and required less recovery sleep afterward.

Many questions remain about these natural short sleepers. Are they missing out on important “restorative” time, or is their sleep simply more efficient than the average person’s? Do they develop cardiovascular or cognitive problems as they age, like those who are regularly sleep-deprived? Are they at increased risk for early death? And surely other genetic mutations for short sleep exist — what are they?

The next time you see a frazzled co-worker bragging that they can get by on just a few hours of sleep, chances are they’re not actually doing so well. The get-up-and-go attitude of the modern American work life does not make sense for our bodies. And your boss might be hard-pressed to admit it, but napping is just as important as checking your email.

Jordan Gaines Lewis is wrapping up her PhD in neuroscience at the Penn State College of Medicine, studying sleep apnea in adolescents. Her writing has appeared in Scientific American, The Washington Post, The Guardian, Popular Science, and TED; and on NBC. She blogs about neuroscience at Gaines, on Brains. Follow her on Twitter.