Do your summer plans include eastbound, transatlantic travel? If so, take precautions to avoid jet lag—the sleepy, sluggish, headachy feeling and insomnia that can seriously curtail your enjoyment of the first few days.
Here’s advice on how to prevent severe jet lag and hit the ground ready for action.
Why Jet Lag Occurs
Body processes occur in a 24-hour cycle tuned to daylight and darkness in the time zone where you live. Eastbound travel over multiple zones is a challenge. To adapt to time in the new zone, your body clock has to advance by several hours. For many people, achieving this phase advance is harder than the delay that occurs with westward travel.
Symptoms of jet lag are more pronounced in some people than in others. But the more time zones crossed, the more severe the symptoms usually are. Jet lag symptoms also seem to grow worse with age. And although I have no hard evidence, I think people with insomnia, who have to be careful about scheduling their sleep anyway, may have more trouble adjusting to changes in distant time zones. I know I do.
Exposure to Light: Get It Right
Your biggest help or hindrance to adjusting to the new time will be the sun. To calculate whether to step right out into the sunlight when you deplane or wear dark glasses during the first few hours of the trip, consider these things:
- Time of arrival at your destination
- Time difference between where you live and where you’re going
- Time you normally get up in the morning
Your habitual rise time matters because of what it implies about daily changes in your core body temperature. Your temperature reaches a low point about 2 hours before you normally get up. Light exposure after your normal temperature low is going to advance your sleep cycle, which is what you want if you’re traveling east. Light exposure before that normal temperature low is going to delay your sleep cycle, making it even harder to adjust to time in a distant eastward zone.
Let’s say you live in the eastern time zone of the U.S., which is 5 hours behind London time. You book a night flight, leaving at 11 p.m. Eastern Daylight Time (EDT) and arriving in London at 11 a.m. British Summer Time (BST). Let’s say you typically get up 6:30 a.m., so your body temperature low would fall around 4:30 a.m. Your arrival time—11 a.m. BST, which is 6 a.m. EDT—occurs after your normal temperature low. Immediate exposure to sunlight upon landing will help adjust your body clock to British Summer Time.
But let’s say you book an earlier flight, leaving at 8 p.m. EDT and arriving at 8 a.m. BST—which is 3 a.m. EDT. This flight would get you into Heathrow before your normal body temperature low of 4:30 a.m. Immediate exposure to daylight upon arrival will push your sleep–wake cycle even further out of sync with the new time than it would otherwise be. This will make your jet lag worse.
If your flight arrives before your core body temperature low, keep plane shades drawn and wear dark glasses until you’re past the time of your normal temperature low. Only then is it going to work to your advantage to expose yourself fully to daylight.
Melatonin Supplements Can Help
Taking a melatonin supplement (sold over the counter in the U.S.) is another jet lag remedy, especially for travel across 5 or more time zones. Your body itself produces melatonin starting a few hours before your normal bedtime in physiological levels of about 0.3 mg. According to a 2015 review in Current Sports Medicine Reports, both low (0.5 mg) and high (3 to 5 mg) doses of supplemental melatonin—taken 1 to 4 hours before the desired bedtime at your destination—can advance the sleep cycle, which should help to prevent jet lag symptoms associated with eastbound travel.
Higher doses may put you to sleep sooner. They may also result in a “hangover” the next day. Melatonin has not been found to have other side effects in healthy human beings. But it is not recommended for people with epilepsy or those taking warfarin.
Comfort During Your Trip
No diet has been scientifically proven to reduce jet lag. Caffeinated beverages can of course perk you up when you’re flagging, but if you want to avoid some of the stomach upset associated with travel, remember in general to (a) stay well hydrated with nonalcoholic, noncaffeinated beverages on the plane and (b) eat plenty of fruit and vegetables. Anecdotal evidence coming out of Harvard suggests that fasting immediately prior to and during a flight, and then eating at the soonest mealtime after landing, may reduce symptoms of jet lag.
With that, I’ll wish you bon voyage and plenty of restorative sleep to power you through your trip!