Health Library - Jet Lag

Health Library - Jet lag treatment

Jet lag was first brought to the public's attention by the pioneering US aviator Wiley Post, who experimented with different regimes to break his eating and sleeping habits.

After flying around the world, he wrote the book 'Around the World in Eight Days', which discussed his attempts to reduce jet lag. But why does air travel affect us in this way?


Rhythm and blues
The earth is divided into 24 time zones: time changes by one hour for every 150 degrees of travel east or west of the Greenwich meridian. Our bodies are programmed to be active and alert during the day and to sleep at night. Travelling across the earth's time zones disrupts these natural rhythms, resulting in extreme tiredness.

Other symptoms can include insomnia, stomach upsets, aches and pains, and a sense of disorientation.

Farrol Kahn, a medical author and director of the Aviation Health Institute, agrees that jet lag disrupts the body's circadian rhythms and is caused by long-haul travel, but adds another important factor is the lower level of oxygen in aeroplane cabins.

"There is 20-25 per cent less oxygen in the cabin when you fly and that's really the cause of jet lag." Lack of oxygen impairs both physical and mental performance, he points out.


When in Rome
Farrol advises changing your watch to your destination time as soon as you board the aircraft and to eat little during the journey.

Resetting your watch on board may not be a good idea for everyone. If you take regular medication, eg for diabetes, watches should remain on home-time until you are able to adjust your medication to local time at your destination, or as suggested by your doctor.

Avoid alcohol and caffeine, and drink plenty of water to combat the dehydrating recycled cabin air.

Many long-haul flights are at night: ear plugs and eye-masks are inexpensive ways to help you get some sleep.


Symptoms of jet lag

• Extreme tiredness
• Insomnia
• Stomach upsets
• Aches and pains
• Disorientation

When you arrive, going for a nap is the worst thing you can do, because it sets your body's rhythms back to home time. Staying active on arrival will help the body adjust to the new time zone.

Eating and sleeping are your body's time indicators, so it's important to fit in with what the locals are doing when you arrive. Consequently, if it's breakfast time, eat breakfast.

Exposing yourself to as much daylight as possible might also be a good idea, because it has been shown that bright light can help to reset circadian rhythms.


Other ways to tackle jet lag
It may be an idea to split your journey if you can, stopping off in Los Angeles or Singapore if you are on your way to Australia, for example.

"Enjoy the open air and then get on the plane; do the next 10 or 11 hours," Farrol says. "If you don't do that and you do it all in one go, you're going to pay for it because the jet lag will last longer."

There are also medical solutions. If you have important meetings scheduled, it can be worth asking your doctor about the possible benefits of a mild sleeping tablet for two or three days while you adjust.

The drug melatonin is also often used by travellers in the US. Melatonin is a hormone that is produced by a small gland under your brain. It's released in the evening and tells your brain it's time to sleep - this is part of your body clock. There have been a number of studies to see if taking melatonin supplements can prevent jet lag, but results have been mixed. The hormone helps to synchronise the body but research on its effectiveness is limited. Jet lag does not need to ruin the beginning or end of your holiday. With a little planning and sensible preparation, you can minimise the adverse effects of flying.


References
Vivienne Russell, NetDoctor, Patient UK, The National Travel Health Network and Centre (NaTHNaC), Aviation Health Institute.