Medicine for the Outdoors
Medicine for the Outdoors

Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.

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Tips to Beat Jet Lag

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Wilderness medicine and outdoor health persons are commonly world travelers. Certainly, being on the lecture circuit or traveling to some far-off place for adventure, science, or clinical service takes me and many others across time zones in both directions. Jet lag is one scourge of travelers and can certainly render worthless the first few days of a journey. I've personally tried just about all the tricks in the book to avoid or mitigate jet lag, so am always on the lookout for a new tip on how to handle the affliction.

Robert Sack, MD wrote a "review article" entitled "Jet Lag" in the New England Journal of Medicine (N Engl J Med 2010;362:440-447). He is from the Sleep Disorders Medicine Program at the Oregon Health and Science University, so this is trustworthy information.

The Circadian Clock

As described by Dr. Sack, jet lag is a sleep disorder that results from crossing time zones too rapidly for the human circadian clock to keep pace. The circadian clock is located in the hypothalamus, and is normally synchronized to the solar light-dark cycle. It is slow to respond to changes in this cycle, so it takes time for us to adjust after we have crossed time zones. It has been estimated that the circadian clock resets an average of 92 minutes later each day after a westward flight and 57 minutes earlier each day after an eastward flight. Have you noticed that it is more difficult from a jet lag perspective when headed west to east?

Treatment Strategies

Dr. Sack explains treatment strategies:

  1. Realignment of the circadian clock by using appropriately timed exposure to light
  2. Administration of melatonin, perhaps in combination with appropriately timed exposure to light
  3. Practicing the optimal timing and duration of sleep
  4. Using medication or caffeine to counteract the symptoms of insomnia or daytime sleepiness

In greater detail, according to Dr. Sack, timing of exposure to light is the most important cue for synchronizing circadian rhythms in humans. One shifts the clock to a later time by exposure to light in the evening, and shifts it to an earlier time by exposure to light in the morning. The timing of sleeping in and of itself does not reset the clock. To simplify the recommendation, when traveling eastward across up to eight time zones, one should seek exposure to bright light in the morning. When traveling westward across up to eight time zones, one should seek exposure to bright light in the evening. An additional tip is to stay indoors for the first few hours of daylight after long eastward flights or for a few hours before dusk after long westward flights.

Melatonin

Melatonin is a hormone secreted for roughly 10 to 12 hours at night. It can be considered to be a darkness signal, with effects opposite those of exposure to light. Therefore, if melatonin is taken in the evening before it would normally be secreted, it resets the body clock to an earlier time, and when it is taken in the morning, it resets the clock to a later time. Taking exogenous melatonin has been studied in a variety of manners. There is no single recommendation for dose or timing of administration in the literature, but Dr. Sack recommends the following: To promote shifting of the body clock to a later time (traveling westward), take 0.5 milligram (a short-acting dose) during the second half of the night until you have become adapted to local time; to promote shifting of the body click to an earlier time (traveling eastward), take 0.5 to three milligrams at local bedtime nightly until you have become adapted to local time.

Here is a summary of other recommendations, depending on whether a person is traveling westward or eastward:

For Traveling Westward:

Before Travel

1. Shift the timing of sleep to one to two hours later for a few days before the trip; seek exposure to bright light in the evening.

2. Try to get an adequate amount of sleep.

 In Flight

1. Try to be comfortable.

2. Drink plenty of water to stay hydrated. Do not drink caffeine if you wish to sleep. Do not mix alcohol with any sleep medication.

3. Consider a short-acting sleep medication, such as zaleplon (Sonata) at a dose of five to 10 milligrams. Do not take sleep medication combined with alcohol, or if there is a risk for deep-vein thrombosis (blood clot formation in the legs or pelvis).

4. Take measures to avoid deep vein thrombosis. These include changing positions frequently and walking around when possible.

On Arrival

1. Expect to have trouble sleeping until you become adjusted to local time.

2. If you are sleep deprived, take a nap after arrival. Continue to take daytime naps if you are sleepy, but keep them as short as possible to avoid ruining nighttime sleep.

3. Consider using sleep medication at bedtime for a few nights until you are adjusted to local time.

4. Take melatonin as noted above.

5. Seek exposure to bright light in the evening.

6. For the first two days after arrival, avoid bright light for two to three hours before dusk; starting on the third day, seek exposure to bright light in the evening.

7. Avoid caffeine after mid-day because it may interfere with sleep at night.

For Traveling Eastward

Before Travel

1. Shift the timing of sleep to one to two hours earlier for a few days before the trip; seek exposure to bright light in the evening.

2. Try to get an adequate amount of sleep.

In Flight

1. Try to be comfortable.

2. Drink plenty of water to stay hydrated. Do not drink caffeine if you wish to sleep. Do not mix alcohol with any sleep medication.

3. Consider a short-acting sleep medication, such as zaleplon (Sonata) at a dose of five to 10 milligrams. Do not take sleep medication combined with alcohol, or if there is a risk for deep-vein thrombosis (blood clots formation in the legs or pelvis).

4. Take measures to avoid deep vein thrombosis. These include changing positions frequently and walking around when possible.

On Arrival

1. Expect to have trouble sleeping until you become adjusted to local time.

2. If you are sleep deprived, take a nap after arrival. Continue to take daytime naps if you are sleepy, but keep them as short as possible to avoid ruining nighttime sleep.

3. Consider using sleep medication at bedtime for a few nights until you are adjusted to local time.

4. Take melatonin as noted above.

5. Seek exposure to bright light in the morning.

6. For the first two days after arrival, avoid bright light for two to three hours after dawn; starting on the third day, seek exposure to bright light in the morning.

7. Avoid caffeine after mid-day because it may interfere with sleep at night.

The final points made by Dr. Sack include the observations that the benefits of any particular diet or exercise to decrease jet lag are unknown.

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Tags: On the Road

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About the Author

Dr. Paul S. Auerbach is the world’s leading authority on wilderness medicine.

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