Reset Your Body’s Clock

All About Jet Lag

Your body’s internal clock is primarily set by your exposure to light and dark. Dark turns on production of the brain chemical melatonin, a naturally occurring compound that makes you sleepy; light turns production off so you are more alert.

When you travel, the light and dark cues change rapidly—confusing your internal clock and creating the hung-over feeling of jet lag.

Brighten Up with Light  

If you want to avoid jet lag and its attendant insomnia, you need to gradually encourage your internal clock to get in sync with the light and dark cycles at your destination. That happens naturally over a 3- to 14-day period following your arrival. But for those of us who need to hit the ground running, researchers in recent years have found that one powerful way to reset your internal clock before you arrive is to alter your melatonin production schedule with the judicious use of a blue light specifically engineered to emit a particular wavelength, color, and intensity.

Scientists have known for some time that bright light can reset your body’s clock. But until recently the only devices they had to do it with were huge, clunky boxes full of white fluorescent-style tubes that looked more as if they belonged backstage at a sleazy theater than in your home or office. Needless to say, not many people used them.

Now, however, powerful blue LED lights in plastic cases six inches square and an inch thick that slip into a tote or briefcase do the job. They’re so small that some manufacturers have even incorporated blue lights into sun visors you can wear.

To give you some sense of what’s involved in using blue light to prevent jet lag, Apollo Health, the company that made the lights used in most research studies, recommends that those traveling east wake up one hour early three days before they travel and sit near the blue- light box for 30 to 45 minutes each morning. You don’t have to look directly at the light—you can set a blue-light box either beside your computer while you work or on the breakfast table while you eat. It does not emit UV radiation, and it’s not harmful to children or pets. It does, however, bathe you in an electric blue light that makes you look like a member of off-Broadway’s Blue Man Group. Any preschoolers in the house will love it.

A single session with a blue-light box will shift your body clock up to three time zones, according to the manufacturer. Then two days before travel, those traveling east should wake up two hours before their normal wake time and sit near the light a second time. On the day of departure, wake up three hours earlier than your normal wake time and sit near the light a third time.

Slip On Shades

Most flights from east to west take off in the morning. So when you arrive at your destination on the third day, wear sunglasses to make sure that no sunlight hits your eyes before 10:00 a.m. local time and messes up your light work. Even airport terminal lights can affect your body’s time cues, so slip the sunglasses on as you enter the terminal.

When traveling west, use the light in the evening between 7:00 and 8:00 p.m. for 30 to 40 minutes two days before you travel. Use it again the night before you travel, starting an hour later. When you reach your destination, again use sunglasses—this time to protect yourself from any afternoon or evening light. Then ease your internal clock’s transition back to home time by using your light each morning for a few days after you return.

See a Specialist

If you’re a regular road warrior, it may be worth your while to work with a sleep medicine specialist who can take into account the variables of your particular clock genes and scheduling priorities to develop a personal “light” prescription for shifting your internal clock before you travel.

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