Finding Ways to Minimize the Effects of Jet Lag

Jet lag is the price most of us pay for getting to the other side of the world quickly--unless we know how to soften the punch.

One survey of international air travelers reported that 94% suffer from jet lag, half of them with symptoms described as severe. Poor concentration, irritability, upset digestion, hunger at odd hours, depression, daytime sleepiness and fatigue and inability to sleep at night are the complaints most often reported.

For the past 40 years, scientists have been exploring the physiological basis for this wide range of symptoms and have learned a good deal about why the body behaves as it does. As a result, they are devising ways to help us avoid many of the unpleasant side effects usually associated with jet lag.

Chief focus of the research has been the brain’s biological clock--the master timekeeper that “ticks� 24 hours a day inside each of us, regulating important body patterns known collectively as circadian rhythms.

Through its contacts with regulators in other key organs, the master timekeeper is able to orchestrate sleep cycles, hunger, cardiovascular activity, body temperature, alertness and other activities--each one set according to the individual’s home time schedule.

Unless lengthy stops are made along a journey, the traveler’s biological clock remains set on home time for awhile. For each time zone crossed, the average person requires one day at the new location to adjust. This means that on a flight to Japan from the West Coast, it may take a week for the body rhythms to readjust completely.

The rhythms of some internal organs adjust more quickly than others. This can cause problems for a few days because things like hormone secretions, temperature, hunger and the sleep-wake cycle may no longer be in proper sequence with one another. Studies suggest that some of us, especially younger people--those with less fixed body rhythm schedules and those who are highly motivated to enjoy new surroundings yielded by a trip--may adapt more quickly than older people.

The direction of the flight is also an important consideration in how quickly the body rhythms readjust. Travel from east to west is easier to adjust to than west to east.

This happens because westward flights, which travel with the sun, mean the day is lengthened. The body tends to handle that better than it does a shortened day.

Light appears to have a strong influence on biological rhythms, either advancing or delaying the rhythms, depending on the time of day the exposure takes place. This knowledge can be used by travelers to speed up adjustment to a new time zone. For example, sunlight exposure during early morning hours tends to cause the biological clock to advance its rhythms. This is an advantage for travel from west to east. Travelers from east to west should try to get plenty of light late in the day.

Also influential are types of food, fluids and drugs taken before departure and while flying, according to Charles Ehret.

Ehret is a scientist who has spent 40 years at the Argonne National Laboratory studying the effects of various factors on the biological clock and who, with computer expert Bill Ashton, has developed a computer program called Jet Ready that prescribes critical modifications in a traveler’s regular habits.

High-protein foods stimulate the rate of metabolism, while carbohydrates encourage the onset of sleep.

Therefore, Ehret suggests that travelers begin regulating their meals two to four days before departure by making use of these foods as a way of resetting the body’s clock. In addition, his system calls for feasting the first day and fasting the second day, then repeating the sequence for two more days.

Whether feasting or fasting, breakfast and lunch should be high in protein, and supper should be high in carbohydrates. The only difference between feast and fast days should be in the number of calories consumed.

Feast days should be high in calories--perhaps 1,000 more calories than usual. Fast days should be as low as 700 calories for total consumption.

Ehret says it is important to consume caffeinated beverages only between 3:30 p.m. and 5:30 p.m. for the first three days. On the fourth day, drink caffeinated beverages only between 7 a.m. and noon if you are traveling west, and only between 7 p.m. and midnight if you are traveling east.

Be well-rested before starting a journey. If possible, get 15 minutes’ extra sleep each of four nights before departure.

Getting plenty of exercise before leaving and after arriving at a destination helps the body speed up time adjustment.

Exercising en route also is helpful. One way to get exercise on the plane is to walk the aisles to fetch frequent glasses of water, which can help avoid dehydration. Practice tensing and releasing different groups of muscles alternately to feel relaxed.

Drink fruit juice instead of carbonated beverages. And to keep yourself awake, engage in conversation with seatmates during hours when it is appropriate to be awake at your destination.

Experts differ on whether sleeping pills are useful. Dr. William C. Dement, a Stanford sleep researcher, believes that a short-acting sleep medication can be useful.

A National Institute of Mental Health conference recommended use of a short-acting benzodiazepine drug, Dement said. Other doctors advise against sleep medications, especially for older people. Consult your physician before taking any.

Useful books on jet lag include “Overcoming Jet Lag� by Charles Ehret (Berkeley Press, $5.95); “A Traveler’s Guide to Jet Lag� (Sigma Graphics, Santa Barbara, $1.95).

For more information on the Jet Ready computer program, write 12672 Skyline Blvd., Woodside, Calif. 94062.