Even the most frequent fliers flounder when it comes to fighting the effects of long-haul air travel. While we know what causes jet lag—a disruption to the circadian rhythms that regulate the body’s normal sleep/wake cycles when crossing multiple time zones—nobody really knows how to conquer it.
As a result, a virtual cottage industry has sprung up around jet lag cures. Sites peddle everything from light boxes (more on that in a moment) to hormone supplements to pricey headphones that promise to reset your internal clock. To make matters even more confusing, every traveler has a personal folk remedy, diet, or coping technique they swear by. (Flashlight behind the knee anyone?)
So when it comes to jet lag, we wanted to know what really works and what’s just magical thinking.
To find out, we turned to Jamie Zeitzer, Ph.D., Associate Professor of Psychiatry and Behavioral Sciences at the Stanford Center for Sleep Sciences and a leading sleep researcher. Here’s what he had to say about common jet-lag cures.
Air travelers are generally advised to stay away from alcohol, but “as all things in science, it’s mixed,” Dr. Zeitzer says. Alcohol does two things, he explains: “It will dehydrate you and make symptoms worse, which is a negative. But if you’re anxious about flying and a little alcohol makes you less anxious, that’s a positive, especially if your focus is just not being awake during your flight.”
Bottom line: A small amount of alcohol can be useful in combating the effects of jet lag, especially if it helps nervous flyers calm the jitters so they can rest.
A hormone produced by the brain’s pineal gland, melatonin helps regulate sleep. Melatonin supplements, available over the counter, are made from— yes—the pineal glands of animals. Doses of melatonin “can help a little if they’re properly timed,” says Dr. Zeitzer. “They’re also a pretty darn good placebo,” he adds. Melatonin is most effective if taken two hours before your target bedtime. The downside: Melatonin is the only over-the-counter hormone not regulated by the FDA. “There might be concerns about the purity and potency of what you’re getting at your local Duane Reade.” (For more on melatonin, see The Big Problem With Natural Sleep Supplements.)
Bottom line: “Minor” sleep-inducing effects of melatonin might help reset the body’s circadian rhythms.
Some travelers swear that drinking a cup of joe cuts through the fog and gets them back on track after an overnight flight to a different time zone. “It’ll get rid of a lot of the negative psychological aspects of the jet lag, sure,” Dr. Zeitzer says. “The physiological benefits aren’t as great as the psychological benefits.” Researchers at the University of Colorado found that coffee can in fact have a small effect on the body’s internal clock, delaying circadian rhythms by about an hour. That could be helpful for flying west, the researchers concluded, but could actually make jet leg worse for travelers heading in an easterly direction.
Bottom line: The power of coffee to combat jet lag is minimal—and depends on which direction you’re going.
There’s no disagreement about this one. “Exercise is great” to help fight the sluggishness caused by jet lag, the doctor advises. To double the impact, exercise outdoors; you’ll get the regular energy boost of a workout, along with the benefits of exposure to daylight, a critical part of helping the body readjust after a long flight.
Bottom line: Walk, jog, trot, run…. Just exercise outdoors.
Perhaps you’ve seen a portable light box. Those glowing rectangles emit bright light intended to shift your body clock and help you adjust to a new time zone. Scientists agree: Light boxes work, says Dr. Zeitzer. “The big problem is whether you want to sit in front of one for hours. It’s not the most convenient therapy,” he says. Getting outside is a more effective way of absorbing light. Even a gray, dreary morning offers more stimulating light rays than an artificial source.
Bottom line: Light boxes work to “phase shift” circadian rhythms. Nature works better.
You arrive at your destination, and you’re exhausted. Should you succumb to the fatigue and take a nap or push through? “It’s tricky,” Dr. Zeitzer says. A nap “is great in the sense that you’re regaining some of the sleep you’ve lost en route,” he says. But if napping means you’re missing out on natural light, it might actually take longer for your body to adjust to a new time zone. There’s another complication, he points out: “Sleep is zero-sum game. Napping too much during the day can make it more difficult to sleep at night.”
Bottom line: Limited napping can help you get back on track, but don’t miss out on daylight by staying in bed too long.
According to one study, “the international traveler can avoid jet lag by simply not eating for twelve to sixteen hours before breakfast time in the new time zone.” Not so fast on the fast, says Dr. Zeitzer. “There is some data out there, but I’m not convinced,” he says. “It won’t affect jet lag in any functional way.” The theory behind fasting has to do with resetting your central circadian clock. According to researchers at Harvard, not eating temporarily “suspends” the body’s master clock; resuming with the appropriate meal in the new time zone restarts it. While it’s an intriguing theory (made easier by the appeal of airplane food), there have been no organized human trials to put it to the test.
Bottom line: Eat if you’re hungry, fast if you’re not. But don’t count on food deprivation to fight jet lag.
“I’m not someone who’s going to say no to sleeping pills,” says the good doctor, who acknowledges that pharmaceuticals are his preferred method of coping with jet lag. “Used judiciously and with forethought, they can be beneficial. Sleeping pills don’t put you to sleep, but they do put you in a state of not being awake. If you’re going to have anxiety about flying, and this helps, so be it. If you can deal with it non-pharmacologically, great.”
Bottom line: Use sleeping pills in moderation if they make you more comfortable.
At the end of the day, Dr. Zeitzer stresses, “it’s all about the light” when it comes to combating the biological effects of jet lag. “That’s the critical aspect. The other stuff is all about minimizing anxiety. Anything that relieves the stress of being in a confined space for a long period of time is good.”