Can Changing Time Zones Affect Your Health?

Time Zones

Photo: Pond5

The security lines are endless, the airplane food is terrible (or non-existent), and you’re lucky if your luggage arrives on time and intact. Yet the worst part of traveling might very well be the groggy, out-of-sorts feeling that can stick with you for days after a long flight. Frequent fliers know it well, and no one enjoys it — but is it actually unhealthy? 

Unfortunately, it can be, says Joseph Ojile, M.D., founder of the Clayton Sleep Institute in St. Louis, MO. “Jet lag occurs when the time of day doesn’t line up with your body’s internal clock,” he explains. If you crossed two time zones, it should take you about a day to readjust; if you crossed six, it could be three days or longer before you feel like yourself again. Doing this once in a while, say, a few times a year, shouldn’t cause any serious problems. But more frequent changes can spell trouble.

“If done chronically, it can lead to a suppressed immune system, chronic fatigue and memory issues.”

Ojile likens it to chronic sleep deprivation: An occasional all-nighter is rough, but you bounce back. Skimp on shut-eye regularly, however, and you’re putting your health at risk. Same goes with time zone jumping. “If done chronically, it can lead to a suppressed immune system, chronic fatigue and memory issues,” he says. In fact, research from the U.K. found that airline cabin crew members (who experience repeated bouts of jet lag) performed worse on memory tasks than those who worked only on the ground (and do not shift time zones). The cabin crew also had elevated levels of cortisol, a stress hormone that, in excess, can lead to high blood pressure and high blood sugar (pre-diabetes or diabetes). It can also cause you to pack on unwanted pounds.

It’s clear — jetsetters should take heed. While there’s no perfect cure for jet lag, following these steps can lessen the toll on your body, and make you feel a lot better. 

Healthy Tips for Changing Time Zones 

1. Plan ahead. “In the days prior to departure, try to move your body’s time clock toward the destination time zone,” says Ojile. If you’re heading east, start getting up and going to bed earlier than usual; if you’re flying west, shift your wake and bedtime later. (For the record, “west is best”— meaning it’s typically easier on your system to go west than it is to go east.)

2. Drink up. That means water, not alcohol. Staying hydrated is important, so sip frequently while you’re in transit and upon arrival.

3. Get on schedule. Try to choose a flight that gets to your destination in the early evening and stay up until 10 p.m. local time. If you arrive earlier and are absolutely exhausted, take a nap in the early afternoon but limiting it to two hours, suggests the National Sleep Foundation.  

4. Let light in. Exposing yourself to the sun’s rays can help your circadian rhythms sync up with a new time zone and clear away that foggy feeling. For personalized advice on how to do this properly, check out British Airways jet lag advisor.

5. Consult an expert. If you travel very often (perhaps for work), it pays to sit down with a specialist. He or she can work with you to map out an individualized plan, which may entail taking the hormone melatonin. Although melatonin supplements are available without a prescription, it’s crucial to get the dosage and timing right — so it’s not a good idea to start popping pills without professional guidance. Find a sleep doc near you at

Happy travels!