Jet Lag: When Your Body Asks, 'Where Am I?'
Tuesday, March 27, 2001
You might spend most of your time on a flight to Europe snoozing peacefully and dreaming of a great trip. But if not, don't try to keep up with the crew: Their job is staying busy and alert. Yours is resetting your internal clock so you get sleepy at a normal hour and get hungry when the restaurants are still open.
Whether you're dozing or downloading at 32,000 feet, you're also crossing several time zones. When you land, your body's daily rhythms -- including temperature changes, metabolism, glandular activity and sleep-wake impulses -- are out of whack with your new location's cycle of daylight and darkness. This mismatch produces jet lag. Left alone, your body gradually will get over the fatigue, insomnia and gastrointestinal distress that often mark the condition, but by the time that happens, your vacation -- not to mention your business trip -- may be over.
Scientists have been working for decades on ways to cause the brain to adapt quickly to a new time zone. Laboratory studies have found that exposure to bright light is the best tool for shifting sleep/wake cycles. But it's difficult to use that tool in the real world of airline schedules, passport control and hotel check-in times. (By the way, flying from east to west is easier on your body because you're less likely to lose sleep.)
And another complicating factor has recently been discovered: While the body's "master clock" is centered in the hypothalamus, different parts of the body adjust to time-zone changes at different rates -- with the kidneys, stomach and other organs lagging behind the brain.
"Jet lag isn't [merely] a lag between you and the outside world; instead, it's a lag between different parts of your body," explains Thomas Wehr, chief of the biological rhythms section at the National Institute of Mental Health. "If you're flying east to Europe, your brain could be in Ireland, and your liver could be in Iceland, so things are not cycling in sync with each other."
Mainstream MeasuresTo fight jet lag, your primary care doctor is likely to advise simple measures. That means
Phyllis Zee, a neurologist who directs the Sleep Disorders Center at Northwestern University Medical School in Chicago, says international travelers actually face two issues, sleep deprivation and circadian rhythms that are out of sync with the new environment. "I think for my patients sleep loss is a big problem, and that's easier to correct more quickly, particularly if they are only going to be gone several days."
Zee's strategies includemelatonin (more on that below),
While that's the standard advice, some experts recommend other steps.
Wehr, for example, advocates
His advice: While in flight, try to
"People think being immediately active will help you adjust, and that's exactly wrong," Wehr says. "If you get exposed to light before 10 a.m., that's going to make the jet lag worse." Wehr says he used to suffer terribly from jet lag but now finds it easy to adjust to a new time zone.
Other sleep experts recommend small doses of
There's no firm evidence that melatonin eases the symptoms of jet lag. Indeed, in a double-blind study published in October by British researchers, the drug performed no better than a placebo for a small group of travelers flying from London to Australia.
While much remains unknown about melatonin's effects, especially when used with other medications, its mainstream advocates say the drug is worth considering: It won't work for everyone, but it's almost certainly safe when used under medical supervision and in small quantities (1 milligram or less, even though many melatonin pills contain 3 mg. or more).
Another approach is offered by Charles Ehret, senior scientist emeritus at Argonne National Laboratory, a Department of Energy research center outside Chicago. He doesn't have much research -- on humans, anyway -- to prove it, but he says travelers can adjust their internal clocks quickly using a diet he developed more than two decades ago.
Ehret's plan calls for four days of alternate feasting (high protein breakfasts and lunches to stimulate the body's active phase, high carbohydrate dinners to wind down) and fasting before travel.
Alternative ChoicesThere's no hard science to support alternative measures for jet lag, but some people swear by them.
Rebecca Wynsome, a naturopathic physician in Seattle, suggests taking 3 mg. to 5 mg. of
Other alternative practitioners say relaxing activities such as hot baths and gentle walks can help you sleep in a new time zone.
Steve Given, a licensed acupuncturist who runs the Chinese medicine program at the Bastyr Center for Natural Health in Seattle, says jet lag can be minimized by focusing on
He can't prove this works, but he says, "I've done it for myself. It will still take awhile to adjust, but you'll adjust faster and be a little more comfortable."
Resources For further information on melatonin, visit the American Academy of Family Physicians' Web site: familydoctor.org/handouts/258.html or contact the National Sleep Foundation: 1522 K St., NW, Suite 510, Washington, DC 20005; www.sleepfoundation.org/publications/melatoninthefact.html
For information on circadian rhythms, go to the National Institute of Mental Health's Web site: www.nimh.nih.gov/publicat/bioclock.cfm
For free instructions on how to use the Argonne diet, send a self-addressed, stamped envelope to: Anti-Jet-Lag Diet, Office of Public Affairs, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439.
Treatment of Choice is an educational column and is not a substitute for medical advice from your physician. To ask questions or suggest topics for coverage, send e-mail to firstname.lastname@example.org or faxes to 202-334-6471. You may also reach us by U.S. mail at Treatment of Choice, Health Section, The Washington Post, 1150 15th Street NW, Washington, DC 20071.