Having Trouble Getting Enough Sleep? Blame Your DNA
Research in the emerging field of chronobiology points to the importance of learning to master our own biological clocks.
To most of us, eight hours of sleep sounds like heaven. And yet, the majority of Americans are REM-deprived. We have high-end beds and pillows, temperature-controlled rooms, darkening curtains, white-noise machines, aromatherapy and other gadgets—not to mention a readily available pharmacopeia—designed to help us fall and stay asleep.
So why can’t we?
Circadian rhythms—our biological responses to light and dark—have been acknowledged for decades. Now, scientists say that it goes much deeper than that, all the way to our DNA. The most important clock is not on our nightstands, phones or watches— it’s in our bodies. “This biological clock is conserved in all life on Earth,” says David Dinges, a professor at the University of Pennsylvania and chief of its division of sleep and chronobiology. “That clock is in every cell of the body.”
That big news resulted in a 2017 Nobel Prize win for Jeffrey Hall, Michael Rosbash and Michael Young, researchers in the emerging field of chronobiology. Their work earned them recognition in the medicine and physiology category. But really, they should’ve been considered for a peace prize. If everyone understood chronobiology, the world would be a much happier place and we’d all sleep better at night.
Among the Nobel laureates’ discoveries: a series of genes regulate biological clocks, and they exist in mammals, reptiles, plants and all other life forms. “In recent years, researchers have discovered that each of us has a unique, genetically determined ‘chronotype’ or clock that programs our ideal sleep time in the 24-hour cycle,” noted the Nobel committee, emphasizing the discovery’s important implications for human health.
So how does a good night’s sleep make you feel refreshed? It’s happening on a genetic level. Certain proteins degrade while we’re awake and recompose while we sleep, which help us function at optimum levels. The researchers showed that, without enough sleep, those important proteins can’t regenerate. That creates chrono chaos, one of Dinges’ more frightful terms. “The body’s clock never goes away,” he says. “We’re dormant at certain times, for certain amounts of time, because that’s what our bodies require. When the system is disrupted, bad things happen.”
Jet lag, “mommy brain,” and even Netflix hangovers are likely caused by half-baked proteins. And then there are teenagers, who seem perennially sleep deprived. They probably are, says Dr. Vatsala Ramprasad, a pediatric pulmonologist and sleep specialist with Crozer-Keystone Health System. “At around age 13, the biological clock shifts backwards,” she says. “Some kids who used to go to bed at 9 p.m. don’t get sleepy until 10:30 p.m. Kids may still have to get up at 6 a.m. but they don’t want to get up until 7:30 a.m.”
Hence, sleep deprivation. All human adolescents have the shift, Ramprasad says, and it’s somewhat related to puberty—but not entirely.
Some things—like too much caffeine, sugar or screen time—create bad sleep hygiene, the trendy name for environmental factors that rob us of sleep. But insomnia existed long before computers and Starbucks, and it does seem to run in families. Melatonin production and a variety of other biological components are often to blame, and those can be hard to correct. “Sleep can be fragile,” Dinges says. “In terms of sleep drive and quality of sleep, some people carry vulnerabilities genetically.”
Certain folks are what Dinges calls “short sleepers” and may function well on less than eight hours of sleep. But those who get thrown into chrono chaos may also have mental health issues like anxiety or be overweight. The inability to regulate sleep might be linked to an inability to regulate eating, Dinges says. Research shows that people gain weight when they get four less hours of sleep for a few days. “They eat more and crave fats because the brain thinks it’s starving when it’s sleep deprived,” he says. “This is just one of the metabolic disturbances created by the body’s internal clock.”
Is it possible to master our chronobiology? “We can discover our own rhythms, but the world generally operates on a rigid schedule, like when school starts,” Ramprasad says. “The situation may get better in college, when students can make their own schedules. Adults, by selection, may chose jobs that allow them to stay up late and go to work late.”
Or that may disturb their chronobiology even more. Our bodies have entrainment systems that allow us to function according to the planet’s orbital rotations. “Humans are genetically synced to this planet,” says Dinges, “which means that over many millennia, our bodies have learned that the optimal time to be awake is when it’s light and sleep is when it’s dark.”
That’s why babies have trouble sleeping through the night and eat at all hours. Their bodies are not only growing, but adapting to Earth.
The rest of us should be as diligent about recharging our bodies as we are about recharging our phones, the experts say. We need to listen to our inner clocks instead of trying to reset them—because, as of right now, there isn’t an app for that.