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Did you once travel across 6-8 time zones and developed the following symptoms;
Insomnia
Daytime sleepiness
Diminished physical performance
Cognitive impairment
GI disturbances
That's right! Jet lag is a sleep disorder, although medically benign and self limited within 1-2 days, symptoms can continue until the biological clock in your brain is adjusted to time in the new destination. Jet lag can cause 'serious misjudgments in business or professional dealings' and knowing how to deal with it will make your life less of a 'sleepy' one!!!
So is there an actual clock ticking in your brain? of course there is!!!
Located in the suprachiasmic nucleus in the hypothalamus, right above your inner nose cavity, is where the 'circadian' clock lies. Circadian is derived from latin for 'around the day'.
The Circadian clock responds to the on-and-off cycles of solar light so that it helps you go to bed during night and increases alertness during daytime. It does that cleverly by special nerve cell pathway which starts from the back of your eyes and goes to the hypothalamus, where circadian cells live. Circadian nerve cells can develop a specific pattern of releasing electrical nerve impulses that is specific to length of day and night. In other words, they memorize when night is going to fall. So, they send messages to another tiny structure in your brain called 'pineal gland', which release the hormone melatonin at night to make you feel sleepy.
The problem with jet lag now is that this clock is very old fashioned and needs lots of time to adjust to time of day and night in the new destination. I am sure you're asking now a very intelligent question; can we make it adjust faster? Yes you can!!!
The simple way is to do the opposite of vampires - get as much bright light exposure in the best time of the day as you can. This is recommended in the morning after eastward travel and in the evening after westward travel. I am afraid readjusting the timing of your sleep does not reset the clock.
However, changing your bedtime before flight can shorten the jet lag; it's recommended to shift your sleep time 1-2 hs in accordance to destination time before take off.
If you're getting an overnight flight, like I always do, then you will feel inevitably sleepy during the first 1-2 days in your destination and might need extra recovery sleep to compensate. It is best to avoid longer naps during daytime because they do no good to your nighttime sleep and will reduce your chance of getting some good quality light exposure necessary for resetting your brain clock. So, 'short' naps are better and more effective in order to make you feel less sleepy during daytime.
Early this month in a review in the New England Journal of Medicine, Dr Robert Sack, a psychiatrist specialized in sleep problems from Oregon University, Portland, suggested an alternative way into reseting your brain clock. He discusses the evidence of using melatonin as a night signal. So you can take 0.5-3 mg melatonin at local bedtime nightly if you're going eastward until you get adapted, or 0.5 mg slow short acting dose in the second half of night if you're going westward.
Another option is to sleep in the plane, which I personally can't do to be honest, unless of course if you force yourself into reading a book of medical statistics - what a powerful hypnotic!!! Of course, you don't have to do this torture to yourself! You can take zaleplon, a sleep pill that has 2-3 hr duration of action. If you want to sleep more, then zolpidem and eszopiclone are preferred- a word of warning though, these two can cause grogginess on arrival and can make you feel grumpy rather than shinny!!
You should avoid alcohol if taking these pills. Also if you're at risk of deep vein thrombosis (a condition where blood in leg veins is prone to clotting) eg had a knee surgery, previous history or pregnant, then avoid them.
Table below is from Sack (2010), and summarizes the different approaches one can entertain.
We wish you a safe and comfortable journey wherever you're going!!
Reference;
R. Sack. Jet lag. 2010. NEJM.(362); 440-7.
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