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Thursday, May 23, 2013
Jet lag syndrome, also known as "time zone change syndrome", is a common problem associated with airline travel across multiple time zones. The majority of individuals traveling across 5 or more time zones will experience jet lag to some degree.
Jet lag is the result of a rather sudden mismatch between the body's own internal clock (circadian rhythms) and that of the environment around us. The body's circadian rhythms usually cycle somewhere between a 24 to 25 hour time period and tell us when it is time to go to sleep and when to awaken. These rhythms are reset daily to match a 24 hour day by factors such as exposure to daylight and social cues, for example when meals are eaten. However, when traveling across multiple time zones rapidly (i.e. by jet flight), these influences now occur at times different from what the body is expecting, and this mismatch can result in problems.
Common symptoms include difficulty falling asleep, poor sleep, daytime tiredness, difficulty concentrating, and sometimes nausea. Most individuals can adapt to a new time zone within 2-3 days. However, depending upon the individual and the number of time zones crossed, symptoms can linger for 5-7 days in some cases.
Traveling eastward, as opposed to westward, is a more difficult adjustment for the body. This is because it is easier to lengthen internal rhythms to a day longer than 24 hours than it is to shorten them to a day less than 24 hours. Numerous approaches have been tried to treat jet lag with varying degrees of success.
In the few days before traveling, trying to change your body's internal rhythm to match that of the time zone you will be traveling to may be useful. This can be accomplished by gradually moving (about 1 hour per day) your bedtime and rising time 3 days before travel. Also, trying to time meals to more closely match meal times of your destination may help.
During the flight, staying well-hydrated and avoiding alcohol will minimize some of the symptoms. Upon arrival at the destination, minimizing napping on the first day and eating meals at typical meal times in the new time zone will help. Probably the most important factor to resetting your body clock is obtaining appropriately timed bright light exposure (sunlight is best).
If traveling eastward, then early day light exposure is best. If traveling westward, exposure to sunlight late in the day will help to lengthen your internal clock to match that of the new time zone. However, if you are crossing a large number of time zones (i.e more than 7 or 8), the timing of light exposure can become complicated and it is best to seek the advice of a Sleep Specialist before traveling.
Medications to ease the symptoms of jet lag have been recommended in some cases.
Melatonin - Melatonin, a hormone produced by the brain in response to darkness, helps to promote sleep. It is the most studied medication for the treatment of jet lag when traveling in an eastward direction. Taking 5 mg in the late afternoon, usually starting the day before or the day of travel, and then continuing this for a few days after arrival, seems to help reduce the symptoms associated with jet lag. Appropriately timing the medication for westward travel is more complicated and you should seek advice from a Sleep Specialist before pursing this. This drug is available as an over the counter dietary supplement and therefore is not regulated by the FDA. If considering melatonin, the consumer should look for a reliable source from which to purchase it.
Ramelteon - A melatonin-like medication, ramelteon (brand name: Rozerem) has been recently approved for management of insomnia. This medication, similar to melatonin, may be of benefit in the treatment of jet lag, though it has not studied in this situation yet. Ramelteon requires a prescription from a physician. It has no reported abuse potential and is not habit forming.
Sedatives and stimulants - Other medications that have been tried in jet lag include stimulants to help one stay awake, and sedatives to help one sleep [benzodiazepines such as triazolam (brand name: Halcion) and nonbenzodiazepines such as zolpidem (brand name: Ambien) or zopiclone (brand name: Lunesta)]. There is limited information on the use of these agents in jet lag. Stimulants such as caffeine or prescription drugs, may be helpful in keeping one awake in the new time zone, but have side effects such as insomnia and sleep disruption that may actually worsen the situation. Similarly, some of the sedatives can be helpful with improving sleep quality, but many individuals experience side-effects, such as confusion, morning sleepiness, or nausea, that may limit their use. If interested in trying one of these medications, consultation with a Sleep Specialist is recommended.
This article is a NetWellness exclusive.
Last Reviewed: Aug 10, 2010
Dennis Auckley, MD
Associate Professor of Medicine
School of Medicine
Case Western Reserve University
Ziad Shaman, MD
Assistant Professor of Medicine
School of Medicine
Case Western Reserve University