Here’s an Evelyn Wood course in brain chemistry for travelers: The hypothalamus, located in the center of the brain, is the body’s master clock, regulating its circadian rhythm and deciding when it’s time to wake or sleep. (“Circadian” is Latin for “around a day.”) Light signals travel from your retina to a cluster of nerves in the hypothalamus called the suprachiasmatic nucleus, or SCN. The approach of dusk each day prompts the SCN to signal the nearby pineal gland to release the hormone melatonin, which helps regulate the sleep cycle. But crossing multiple time zones wreaks havoc with melatonin production, leading to jet lag and inspiring weary travelers to try innumerable remedies, from acupressure to vitamins and herbal concoctions. The latter, though widely used, work primarily by placebo effect, says travel medicine specialist Stuart Rose, M.D. Here, some of the most tried (and true?) ways of fooling Mother Nature.
The Remedy: On the day of travel, take supplemental melatonin 30 minutes before you plan to sleep (ideally, close to the target bedtime at your destination). Some studies have shown five milligrams to be effective, others as little as 0.5 milligrams. Make sure it’s synthetic, as animal-derived melatonin can be contaminated. Continue taking for several days.
How It Works: Taking melatonin—commonly used for insomnia as well—essentially tricks the body into thinking it’s time to sleep and helps reset its internal clock.
The Results: Several trials suggest that taking melatonin reduces the number of days required to establish a normal sleep pattern, diminishes the time it takes to fall asleep, and reduces daytime fatigue. But some trials have found no benefits, and reported side effects include headaches, nausea, and irritability.
The Remedy: If traveling east, wake up early the two or three days before your trip and expose yourself to bright light using a high-intensity lamp (a number of companies make portable ones) for 30 to 60 minutes, depending on intensity. When flying west, stay up later and use the lamp in the evening—well before bedtime, as it can cause insomnia.
How It Works: High-intensity lamps, which are often used to treat seasonal affective disorder, mimic natural sunlight. They can suppress the body’s release of melatonin, helping to stave off sleep and shift your circadian rhythm forward or backward.
The Results: A study simulating a trip from New York to Hong Kong found that subjects receiving light sessions at progressively later times each day got on schedule at least four days earlier. But tests of long-haul flight crews showed no improvement in jet lag symptoms from light therapy.
The Remedy: Take a sedative such as Ambien, Sonata, or Lunesta (start with the lowest suggested dosage) to help with sleep on long flights and again before bedtime at your destination. (An experimental drug called tasimelteon has shown to be effective for jet lag–related insomnia, but it won’t be available for several years.)
How It Works: Ambien, Sonata, and Lunesta are in a class of sedatives known as non-benzodiazepines. They bind to specific receptors in the brain, activating the release of chemicals that relax the body and induce sleep.
The Results: Unlike the barbiturates once used, these sleep aids have minimal or no hangover effect. Lunesta and Ambien are best if one has at least eight hours to sleep, while Sonata wears off after four hours and is appropriate for shorter flights.
The Remedy: Four days before travel, start a dietary regime that alternates days of high-protein breakfasts and lunches (think steak and eggs) and high-carbohydrate dinners with days of “fasting,” which is defined as 800 calories a day, mainly in the form of salads, light soups, fruits, and juices.
How It Works: Protein helps the body make the chemicals it produces when it’s time to wake up, while carbs help ready the body for sleep. The alternating fasting days deplete the liver’s store of carbs and prepare the body for resetting its internal clock.
The Results: One small study published in the journal Military Medicine found that National Guard troops using the diet (which is known as the Argonne diet) before flying across nine time zones were less likely to experience jet lag.
On a long flight, it’s essential to move around. In addition to walking up the aisle and stretching your arms and legs, Oz Garcia, a New York specialist in nutrition and antiaging, recommends these simple exercises: Squeeze a rubber ball to stimulate circulation in your hands and arms; and while in your seat, lift your knee and flex your foot for a count of ten, then repeat.