during the pandemic, Many people have barely left their neighborhoods, let alone their time zones. But vaccinations are available, cabin fever is rampant, and the holiday travel season is just around the corner. And so, inevitably, it is jet lag.
The human internal timekeeping device, scientifically known as the circadian clock, is a mighty force. It synchronizes functions across organs and tissues, affects cognitive function, digestion, sleeping, And even asthma. Adjusting a biological clock to a new time zone or schedule isn’t as simple as resetting a wristwatch, but current research on how to manipulate it could be useful to anyone, whether they’re traveling home or to Mars.
“There is a lot of hope to come, now that we understand the molecular power of the clock, to harness the power of the clock for good,” says Carrie Bartsch, a professor of biochemistry at the University of California, Santa Cruz who studies the circadian system. She says that the more we understand about the clock, the more freedom we have, because we can make it an ally, not an enemy.
Throughout the body, cells have their own circadian clocks that regulate metabolism and other cellular functions. These clocks coordinate between other cells in certain organs and even between organs – although how to do this is something scientists are still trying to figure out. All of these individual clocks are regulated and synchronized by the brain’s suprachiasmatic nucleus, the “pacemaker” part of the hypothalamus that is highly sensitive to external stimuli, especially light and dark. Light signals mean it’s time to get up and be alert, while darkness means it’s time to slow down and sleep.
While these signals are closely related to the sleep cycle, they also have downstream effects on a range of biological functions. “I think of the circadian pacemaker as an orchestra conductor,” says Erin Flynn Evans, who leads the Anti-Fatigue Actions Laboratory at NASA’s Ames Research Center. It controls a whole range of biological functions. There are biological clocks in the liver, in the intestine, in the reproductive hormones. The main pacemaker in the suprachiasmatic nucleus is kind of synchronizing the timing of all that biological function.”
But the internal time adjuster cannot always keep up with human behaviour. When travelers move quickly across time zones, the biological clock is desynchronized with the outside world, an experience most people know as jet lag. A mismatch can lead to a group of symptoms Including fatigue, blood, insomnia and even digestive problems.
For most people, this is a relatively rare event and just an inconvenience. But for workers like pilots and flight attendants, who may endure these changes daily, jet lag can affect their long-term health. Even relatively short hops affect cognitive function. One 2017 study Published by researchers at Northwestern University they found that professional baseball players who traveled more than two or three time zones for a game played worse. The same problems exist for shift workers like nurses, and people who have irregular work hours like long-distance truck drivers, who work on schedules that keep them up at night.