Snow White: You’re Sleepy! Sleepy: [Yawning] How’d you guess?
Human sleep is largely a mystery. We know it’s important; getting too little is linked to heightened risk for metabolic disorders, Type 2 diabetes, psychiatric disorders, autoimmune disease, neurodegeneration and many types of cancer. “It’s probably true that bad sleep leads to increased risks of virtually every disorder,” says Dr. Louis Ptacek, a neurology professor at the University of California, San Francisco (UCSF). But details about what’s actually going on during shut-eye are sparse. “We know almost nothing about sleep and how it’s regulated,” says Ptacek.
Some people are morning larks, rising early, and others are night owls, who like staying up late. Those patterns are regulated by the body’s circadian rhythm, a 24-hour internal clock. People can manipulate their circadian rhythm through all kinds of external factors, like setting an alarm clock or exposing themselves to light. But the ideal sleep duration has long been thought to be universal. “There are many people who think everyone needs eight to eight and a half hours of sleep per night and there will be health consequences if they don’t get it,” says Ptacek. “But that’s as crazy as saying everybody has to be 5 ft. 10 in. tall. It’s just not true.” […]
“Hopefully in the next five to 10 years, you’d go to the doctor, give a breath test or a pee sample, and the doctor would know your biological time,” he says. “Then all your test results and treatments could be based on your real internal time, which is going to be very different between you and me based on our internal clocks.”
