There are times I find myself enjoying the existentially altered feeling that comes with jet lag—more formally called desynchronosis. Everything is slightly different. You look at the world without your usual filters and expectations, right up to the moment where you find yourself spaced out looking blankly out the window for an hour. And then, the next moment when you wake up hours later not remembering how you made it to the bed you’re laying on.
Most of the time, jet lag sucks.
Like the common cold, there is no magic cure for desynchronosis. It’s the price we pay in exchange for the miracle of rapid global travel. Once you have it, the best you can do is treat the symptoms until it lets go of you. On the other hand, also like the common cold, some cases of jet lag are worse than others. Occasionally, you get lucky and hardly feel it all all.
Years ago, just after takeoff on the first of two flights from California to Europe, I woke up with a very troubled stomach. Something I had eaten or drank at the airport before departure disagreed with me in a violent way and I spent the rest of the flight, my layover, and part of the next sick as a dog. It was the kind of ill that makes you want to crawl up in a hole and disappear from existence. Finally, somewhere over Greenland on the second leg, the last of what tortured me gave up and I was able to pass out in exhaustion. I didn’t wake up again until we touched down at Schipol.
Surprisingly, I felt half-human. By the time I cleared customs, I was downright ravenous. With more than a bit of trepidation , I stopped at a restaurant in the airport arrivals hall to eat breakfast. Thankfully, the food agreed with me. I went to my hotel and spent an easy day reading, ate dinner, and went to sleep. The next morning, I woke at sunrise without a problem and went on to have a wonderful week totally free of most of the effects of jet lag. What started out as the worst flight of my life turned into the easiest week of travel I’d ever experienced up to that point.
Now, eating bad food as strategy to avoid jet lag is probably not a good idea. In fact, it’s a really crappy way to fly. It seemed, however, that what ailed me dampened my circadian rhythms to the point where shifting gears into a new time zone could happen very smoothly. More smoothly than I’d ever experienced before. It worked so well that I wanted to better understand what had happened. So I set out to learn.
According to the science, jet lag results when the body’s natural circadian rhythms for sleep and eating — and to a lesser degree, temperature regulation and a few other rhythms — are out sync with the day/night cycle at your destination.
The sleep clock is the one that everyone focuses on for good reason. It’s the one that is the most obvious. Being wide awake and alert during the middle of the night and passed out on a couch in the middle of the day are hard to ignore. Because it’s so obvious, the sleep cycle is also the one that we typically try to apply brute force to when following the folklore advice to stay awake through the daylight hours when you first arrive.
If only it were that easy.
While it’s true that the sleep clock is driven by light, it is slow to respond to such direct action. There’s also another independent factor at play: your sleep/wake homeostasis.
“Sleep-wake-homeo-what?” you might ask.
Simply, sleep/wake homeostasis a biochemical mechanism that acts as a timer and ensures you get enough sleep. It’s controlled by the amount of adenosine—the natural by-product of using glycogen—and other endogenous chemicals in the brain. When you’re awake, the amount of adenosine goes up and, at a certain point, starts inhibiting alertness and promoting sleepiness. As you sleep, adenosine levels go down. The amount its reduced depends on how much good sleep you get.
You know that shitty feeling that lingers for a few days after you pull an all nighter or two? That’s the effect of your sleep/wake homeostasis being stretched out too far.
I used to have a bad habit when I flew overseas on an early morning flight. I’d put off getting packed until late the night before and then stay up all night packing and putting everything in order. I justified it with the thought that if I was going to be a jet lagged zombie anyway, then why not squeeze some more awake time in?
As a result, I’d head off to the airport and start my trip bleary-eyed. On arrival, I’d swing immediately into gung-ho-must-stay-up-until-evening mode and finish the job of making myself a complete wreck. When I finally let myself crash out after effectively pulling two-all nighters in a row separated by an uncomfortable stretch of sitting in an airline seat, I certainly slept hard. Very hard. But, with such a huge sleep deficit and likely a massive surplus of adenosine already built up, I was compounding the effect of jet lag, guaranteeing a bad experience.
If applying brute force by staying awake all day after flying overseas isn’t a good way to encourage your sleep cycle to transition to a new time zone, what is?
Research in the 1980s by Dr. Charles F. Ehret found that if you hack your food clock, your sleep clock will usually follow along. In other words, while the sleep clock is what you typically focus on when traveling, it’s subservient to your food clock. Based on this work, he developed the Argonne Anti-Jet-Lag-Diet to help government travelers quickly adjust their body to new time zones. It uses a four day feast-fast-feast-fast pattern that ends with breaking the final fast at breakfast time in your destination time zone with a high protein meal.
I’ve executed the full four-day regimen on several trips. In my experience, it doesn’t always eliminate jet lag, but it always has a positive effect. In many ways, it’s like how using decongestants and pain relievers don’t eliminate a cold, but can eliminate suffering through the worst symptoms of one. The biggest challenge adhering to the Argonne diet comes on trips where you return 5–8 days after your arrival. It’s a drag to start being strict with eating again so quickly, especially when you want to fully embrace the unique flavors of your destination or if your schedule isn’t under your control.
Thankfully, research at Harvard by Clifford Saper and his team in 2008 indicates that a fast of 16 hours can help reset your food clock. Instead of adhering to a complex four day long schedule, you simply time your last meal on travel today to be 16 hours before breakfast at your destination. For example, if you’re flying from San Francisco to London, 8AM GMT is midnight Pacific time. 16 hours before that is 8AM in California. So, have a nice breakfast before you leave, then fast until it’s breakfast time in the UK.
In most cases, adhering to a fast on travel day means skipping the main meal on the plane—no great loss considering the current state of airline food, but it can feel a bit awkward to sit there reading a book while everyone else eats. Depending on when you’ll land, you’ll probably want to bring your own food to break your fast. The crappy pastry that’s standard breakfast fare on international flights certainly won’t do the trick, even if it is served at the right time.
In practice—at least in my experience— a single 16-hour fast on the day of travel isn’t as effective as the four day cycle, but it does help. More importantly, you can repeat it as often as needed at your destination. Simply time your last meal of the day before four in the afternoon until you’re feeling solid in your local time zone.
Hacking your food clock can help reset your sleep clock, but how do you help keep you your sleep/wake homeostasis in a good place through your travel day, especially when you’re on a red-eye flying east? The obvious answer: sleep—or at least nap—on your flight to let your body work down the adenosine in your brain. Unless you have the budget for a business class ticket in a fancy lay-flat seat—or the miles and status to score an upgrade—that’s easier said than done.
One of my strategies is to meditate for a while. The process of packing, getting to the airport, clearing security, and waiting around in a terminal puts my mind in a state where it wants to stay alert for the next thing. That interferes with blissfully dozing off. A good long meditation session right after takeoff helps reset that.
My other strategy is a lot less prosaic: diphenhydramine, the active anti-histamine ingredient of Benadryl in the United States. It’s FDA approved as a non-prescription sleep aid and pretty safe for almost everyone to use. It’s also legal to possess most everywhere you go, except apparently for Zambia where it’s a prohibited psychotropic.
One wonders what the Zambians use for mild allergies.
In practice, when I get onto an overnight flight from the US to Europe, I’ll settle into my seat, meditate after takeoff, and, while everyone else eats that first crappy meal, I’ll pop a Benadryl and say good night. When I do it right, I wake up about the time we’re crossing over Scotland.
Now, sleep through medication may not be for everyone, especially if you’re concerned about deep vein thrombosis while you’re wedged in economy class. Only you can decide for yourself.
No matter how well you hack your food clock and get some rest on the flight, you’re probably going to have to deal with at least some effects of jet lag. I’m convinced that the best thing to do—whenever possible—is simply be kind to yourself. Instead of pushing yourself to stay awake when you’re really groggy. Remember, that’s a signal from the adenosine in your brain that you need sleep and you should just take a nap. A few hours of sleep when your body most needs it can do wonders.
What if you don’t have a few hours? Then it’s time for another brilliant hack: the coffee nap. As strange as it sounds, studies show that drinking a caffeinated beverage then immediately taking a twenty minute nap helps clear your head of adenosine more effectively than either drinking coffee or taking a short nap alone.
Another way to be kind to yourself is simply be smart about when you’re going to be alert in your destination time zone. When flying from the US to Europe, I don’t schedule anything important before noon for the first few days after arrival. Likewise, when traveling from Europe to the US, I embrace my temporary status as a morning person don’t commit to anything after four in the afternoon.
Finally, that advice about paying attention to sunrise and sunset is as sound as ever. Sunlight is an important factor in driving the sleep clock and even if you’re doing your best with hacking your food clock, every little bit helps. Furthermore, if it’s dark and gloomy where you’re going—say, northern Europe in the winter—the use of a light therapy device can be instrumental in feeling beter.
Ok. Let’s summarize:
- Fast on travel days and skip the shitty airline food
- Eat dinner before four in the afternoon in the destination time zone
- Eat high protein breakfasts in the morning
- Don’t deprive yourself of sleep
- Embrace being a morning person after flying west
- Embrace being a night owl when flying east