How to survive your very real jet lag

What they're saying: “When we jet into a new time zone, our circadian rhythm is thrown out of sync,” said Rebecca Robbins, sleep researcher and assistant professor at Harvard Medical School. Suddenly, we’re exposed to sunlight at a time that’s inconsistent with our internal clock.

• It's particularly turbulent when you’re flying through more than three time zones and staying in a new place for more than two days, according to the Centers for Disease Control and Prevention.
• When internal and external clocks are misaligned, that can disrupt body temperature, melatonin secretion, blood pressure and heart rate, Robbins told Axios.

The latest: A recent study published in eNeuro — which adds to a growing body of research on the body’s circadian clock — gets at why cross-country travel can be so harmful.

• University of Massachusetts, Amherst research on animals suggests that shifting the time of day that we’re exposed to light and darkness can interfere with the formation of neurons in the brain’s hippocampus.
• Important, because that process supports learning and memory.

Previous studies show chronic jet lag could also be linked to depression, heart disease, cancer and high blood pressure.

• And: Jet lag is considered a sleep disorder.

Even without jet lag, sleeping away from home isn't easy.

• “When traveling, our brains are on high alert, taking in all the new sounds and smells of our new environment and, from an evolutionary perspective, scanning our surroundings for threats,” Robbins said.

To manage jet lag, Robbins says get ahead of it.

• Skip the redeye because you’re not likely to sleep well on the flight. But if you must land in the morning, wear sunglasses or wait until the afternoon to walk around in the natural light.
• Shift your bedtime 15-minutes later or earlier each night — in the direction of your destination time zone — the week leading up to your trip.
• Update your watch and phone to the time of your new destination as soon as you board the plane, and “start eating, drinking and living on the new time,” she said.

Once you land…

• Prioritize exercise. It helps you “stay attuned to the pattern of light and darkness in your [new] environment,” and can help reduce stress.

• Avoid a heavy meal right before bedtime because it could keep you awake at night.
• Only nap when necessary. She recommends 20 or 90 minutes at a time.

The FDA hasn’t approved any medications specifically for jet lag disorder.

• Vanda Pharmaceuticals successfully sued to unseal the FDA's records on the drug Hetlioz, after it was denied to treat jet lag. According to documents Vanda shared with Axios, the FDA cited “the tincture of time” as a jet lag management option.
• The FDA said the drug application had “inadequate data to demonstrate effectiveness.”

Melatonin, a supplement (not regulated by the FDA), has grown in popularity to manage sleep disorders.

• Some studies suggest taking melatonin before sleep can reduce jet lag symptoms after a flight.
• It’s typically considered safe to use short term, but there’s insufficient data on its long-term use, and melatonin bottles can be mislabeled.

Many experts only recommend using sleep aids as a last resort, and with a doctor’s approval.

Go deeper: This app has bedtime recommendations to help you beat jet lag.