Jet-Setters, Put on your Eye Shades Now!

How to help your body beat jet lag

Published: Aug 29, 2009 08:46:10 AM IST
Updated: Aug 31, 2009 06:50:58 PM IST

The JetLag watch does what Einstein was only able to write about. It speeds up or slows down time to ease you into your new time zone and help avoid jet lag.

Jet lag happens when the body’s internal clock falls out of sync with environmental time. Sufferers may complain of fatigue, disorientation, bowel irregularities, mild depression and a headache. A couple of hundred years ago, a creative botanist from Sweden, Karl von Linné, planted a seed that. today, is helping us answer why jet lag occurs. He described a clock that would tell time through an arrangement of plants whose flowers naturally open or close depending on the time of day. He was also clever enough to write about it instead of attempt to grow a flower clock himself.

In the same way that flowers open or close with natural rhythm, various genes in our bodies switch on or off based on the time of day. These genes receive cues from a master clock in the brain, the suprachiasmatic nucleus, or SCN.

The SCN sets its clock based on when light hits the eye. Light stimulates a network of signals that goes via the SCN to regulate melatonin prod­uction. Melatonin is a versatile hormone and powerful anti-oxidant. During darkness the brain produces melatonin that causes drowsiness. Light inhibits melatonin and is one of the reasons why people who have trouble sleeping should keep a pair of eye shades handy when travelling. Not enough darkness (think night-shift workers) is bad for you and can lead to cancer and immune suppression. It is thought that the loss of protective melatonin has a role here.

How does jet lag work? As an example, let’s assume that you head off to London to shop for a JetLag watch. If you sleep at 10 p.m. London time, that would be 2:30 a.m. IST; probably a few hours past your normal bed time. The times at which your body is expecting to eat, sleep, and be active are all off.

When you realise the watch is only available online and decide to fly back, you will experience the directionality of jet lag.  Back in India if you set your alarm for 7:30 a.m., that would be 3 a.m. London time.  It is easier for most of us to stay up later than wake up earlier (my yoga instructor would concur), so jet lag on your eastern or return leg will be more severe. 

Light and melatonin remain the most common treatments for jet lag. Light is the natural cue for the SCN to reset. As a general rule, next time you fly, remember to avoid bright light during the night at your destination. Of course, this includes artificial lights from Vegas casinos and even lumens from your laptop.

During the day, give yourself some natural light. To prevent jet lag before a flight eastwards, sleep one hour earlier and awake to bright light for three days before your flight.

Melatonin is not approved by the US FDA for jet lag, but then many good remedies are not. This has more to do with the economics and non-patentability of melatonin than its underlying science. New drugs that act specifically on melatonin’s receptors to increase its activity are very patentable and are growing in popularity for the treatment of jet lag. If you believe that they work, you should believe that the lower cost melatonin works. In low doses (under 5 mg) and for short time periods as you would need for jet lag, melatonin should be safe. It should be taken 30 to 90 minutes before bed time.

What is the most effective treatment of all? Wake up when it’s bright and sleep when it’s dark. In the proud tradition of Einstein and our Swedish flower man, I here write about something that I probably could not do myself.

Queries or suggestions for Dr Kumar, or our health team, are welcome at

(This story appears in the 11 September, 2009 issue of Forbes India. To visit our Archives, click here.)

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  • Arvind Balaji

    a very intriguing and informative article. keep it up!

    on Sep 5, 2009
  • Melody Hou

    Dr. Kumar,<br /> <br /> Once again you present a cogent and surprising article. I was not aware of the function of this supraorgasmatic nucleus that you mention but now I know what will help me stay awake in the dark lecture halls!<br /> <br /> Thanks

    on Aug 30, 2009