How to win the battle against jet lag

Lots of products promise miracle cures for jet lag. The plethora of panaceas includes herbal homeopathic tablets, melatonin-based liquids, wearable blue-light therapy devices, caffeine pills with B vitamins, and hematite bracelets with supposed “grounding” powers.

Do any of these things work? Research suggests that while some products may help minimize symptoms of jet lag, there are few ways to completely eradicate the groggy stupor that invariably follows flying across multiple time zones. Moreover, chronic jet lag is linked to a host of health issues, including cancer and heart disease.

What’s a frequent business traveler to do? Controlling your exposure to light is key, according to many experts. That’s because light is the primary signal to your internal circadian clock, which regulates melatonin levels and wake-sleep cycles. Jet lag throws off that clock and, the more time zones you cross, the worse you feel—especially when you’re flying east and losing hours.

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One of the most effective ways to speed the circadian-reset process is by tricking your body with light. Does that mean spending a few hours outdoors in a new destination will do the trick? It depends on whether you’re traveling east or west, and on the times you depart and arrive.

The rule of thumb is that if you’re flying east to west, you need evening exposure to light. If you’re going west to east, you need morning light. But research from the Rush University Medical Center in Chicago suggests there are more specific light-based strategies for resetting melatonin levels.

Start by estimating when your body reaches its minimum temperature—generally two hours before your usual wakeup time if you sleep seven hours per night or three hours before waking if you sleep more. When traveling east, it’s best to avoid light for four hours before your body temperature minimum and find light four hours after it. Then adjust your sleep schedule to shift your minimum body temperature time one hour earlier each day. If you’re traveling west, adjust your sleep schedule to shift your minimum body temperature one and a half hours later each day.

If you ignore the optimal light/dark periods and expose your body to light during a dark cycle or vice versa, you run the risk of worsening jet lag and shifting circadian rhythms in the wrong direction.

Several apps can help you develop a multiday schedule that lessens jet lag (see sidebar). But if you need a quick fix for a faster turnaround, some research suggests, the best option is light therapy.

Exposing people to short flashes of light during a sleep cycle hacks the biological clock and resets it faster, according to a 2016 study by the Stanford University School of Medicine. The process, which is most effective at night, tricks your body into adjusting to a different time zone before takeoff and could be more effective than continuous light. The light flashes, which are delivered in millisecond pulses, trigger the retina cells that send light signals to circadian systems and ultimately to the part of the brain known as the hypothalamus. The hypothalamus tells the pineal gland when to release melatonin.

Lumos Tech is delivering on the Stanford research with what it calls a Smart Sleep Mask, which offers personalized light therapy using LED bulbs. While the $175 product isn’t on the market yet, the company website is taking reservations. A smartphone app controls the device, which Lumos Tech hopes to sell to everyone from business travelers and night-shift workers to astronauts.

Some research suggests that like light, eating times play an important role in resetting melatonin and circadian rhythms. There is conflicting data on whether jet-lag diets work: the Mayo Clinic says the strategy is unproven while a 2016 study by England’s University of Surrey found meal times were critical to adjusting circadian rhythms.

For what it’s worth, several dozen travelers have given high marks on Amazon.com to the book The Cure for Jet Lag (originally published in 1987 as Overcoming Jet Lag), which focuses on diet rather than light exposure. The authors, Dr. Charles F. Ehret and Lynne Waller Scanlon, offer guidelines for consuming alcohol, caffeine, and food, starting four days before an international trip. Among their simple rules: restrict caffeine for the first three days, except from 3 to 5 p.m., the only two hours when caffeine doesn’t affect circadian clocks.

According to Ehret and Scanlon’s diet, days one and three are “feast days” of high-protein breakfasts and high-carbohydrate dinners, while days two and four are “fast days” with limited carbs and lots of liquids. The high-protein meals are meant to be stimulants, while the high-carbohydrate meals act as sedatives. On the day before travel, advise the authors, limit caffeine intake to between 6 and 11 p.m. if you’re traveling east and to the morning if you’re traveling west. The book also suggests a high-protein breakfast at the destination breakfast time and staying awake with lights on after the meal.

While this diet may or may not help, there’s little question that alcohol, dehydration, and sleep deprivation can worsen jet leg. So drink plenty of liquids—but not alcohol—and get lots of rest before a trip. And keep in mind that some people withstand time-zone changes better than others—your own experience depends on your light sensitivity and deep-sleep patterns.

Once it’s time for some shut-eye, try strategies to precipitate slumber, such as noise-cancelling headphones paired with a white-noise app. Melatonin may also ease jet lag. A 2002 review by Cochrane, a nonprofit medical research organization, claims it’s most effective if you’re flying east and across five or more time zones. There’s no scientific consensus on melatonin, however—and there’s still wide debate about what best mitigates jet lag.

App Therapy

Several smartphone apps offer tips and schedules to reset circadian clocks to new time zones. Here are three, all of which are free and available for both iOS and Android devices:

Entrain. This app, developed by researchers at the University of Michigan, offers optimal light exposure and sleep schedules based on destinations. Smartphones monitor whether you’re in light or dark environments. The app, while helpful, may not be practical for you if you can’t follow long light or dark periods during a hectic business schedule.

Stop Jet Lag. This app runs on software developed by Dr. Charles Ehret, coauthor of The Cure for Jet Lag. It takes a multi-pronged approach to shifting the circadian clock by monitoring sleep patterns, light exposure, food, and caffeine intake. Melatonin supplements are also recommended during sleep-cycle times at the destination.

Jet Lag Rooster. This app maps out ideal sleep times and light/dark exposure based on your starting point and destination. It also suggests melatonin, and when to take it, to sync circadian clocks. You can start the sleep calculator on arrival or a few days before departure, and use the app’s alarm to signal when to seek light, for example, or when to go to bed.