Troubles falling asleep. Troubles staying awake. Irritability. Stomach problems. It sounds like a list of side effects from the back of a pill bottle — but, in fact, these are just the most typical symptoms of a very common, but very annoying, phenomenon: jet lag.
Anyone who’s ever traveled across time zones is probably familiar with the misery of adjusting to a new schedule. There are oodles of tips out there for making the process easier: sleep through your journey, force yourself to stay awake during normal hours once you arrive, avoid caffeine, go for walks in the sun as soon as you get up in the morning and so on.
In addition to the usual advice — which mostly amounts to forcibly advancing or delaying your sleep schedule — scientists have been investigating new ways to make the adjustment process faster and easier, using everything from pills to flashing lights. Soon, the soul-smothering effects we see as an unavoidable side-effect of travel may be a thing of the past.
The Root of Jet Lag
To understand how jet lag can be treated, it’s important to first understand why it happens. The human sleep schedule is guided by our circadian rhythm — that natural, roughly 24-hour cycle that guides the body’s daily functions and tells it when to sleep and when to wake up. Jet lag is little more than a disruption in this process. When you cross to a different time zone, your body’s circadian rhythm is still on its old schedule — it still wants to go to sleep and wake up at the old times.
Fortunately, the circadian rhythm is adjustable. This is mostly because its major influence is light.
Exposure to light helps control the release of certain hormones in the body that regulate the sleep cycle, the most well-known and well-studied of which is melatonin. Melatonin is naturally secreted by the pineal gland in the brain and helps tell the body that it’s time to go to sleep. It’s released in the greatest amounts at night, when it’s dark out. Light, on the other hand, causes a chemical effect in the body that reduces the production of melatonin and helps the body wake up and stay alert during the day.
This relationship between light our circadian rhythm is why shift work is so notoriously difficult. Even when you’ve been following the schedule for years, getting up in the middle of the night and going to sleep when it’s light out is hard to get used when it goes against the body’s natural rhythm. It’s also why looking at your phone’s screen late at night can delay the production of melatonin and make it harder to fall asleep.
When it comes to jet lag, light can help play a critical role in adjusting to a new time zone. And at the current impasse, it provides the fastest cure: experts agree that waking up at a decent hour (for the new time zone, that is) and immediately going outside and soaking up some daylight can help reset the body’s clock. Going to bed early — and avoiding looking at cellphones, computers or other unnecessary lights before falling asleep — can also help the body get on schedule. Yes, you do have to tough it out for the first few days but after that, your body should be well-adjusted.
What is Science Doing to Solve Jet Lag?
While prescriptive light seems to be the best solution, some researchers are looking into new and innovative ways of fast-tracking the body’s adjustment to another time zone.
Earlier this year, for instance, researchers at Stanford published a study suggesting that exposing people to flashes of light — while they’re sleeping — could help prevent jet lag in travelers.
For the study, the researchers exposed sleeping participants to either short flashes of light (spaced a few seconds apart) throughout the night, or continuous light. While both treatments helped delay the onset of sleep over time, the short flashes had a significantly greater effect.
The study’s senior author, Stanford psychiatry professor Jamie Zeitzer, explained the two major reasons behind this phenomenon in a statement: The first is that the cells in the retina that transmit the light information to the circadian system continue to fire for several minutes after the stimulus — in this case, flashing light — is no longer there,” he said. “The second is that the gaps of darkness between the light flashes allow the pigments in the eye that respond to the light to regenerate — that is, go from an inactive form that cannot respond to light to an active form that is able to respond to light.
Not all research uses light, though. Some scientists have taken their circadian research straight down to the molecular level.
Just last month, researchers at Nagoya University in Japan were able to synthesize a molecule that can help change the circadian cycle. The molecule interacts with certain proteins that help regulate the body’s rhythm, actually lengthening the circadian cycle. It’s possible that it could be used for managing jet lag or treating sleep disorders in the future.
Other scientists have recognized that individual types of cells can play an important role in regulating the body’s clock. While the body’s daily cycle is generally controlled by a central “clock” in the brain, research suggests that many cells throughout the body also seem to have their own biological clocks and perform functions in cycles throughout the day.
For instance, one group of researchers in Canada published a study last year suggesting that glucocorticoids — which belong to a class of steroids — can help shape the rhythm of white blood cells. For now, they’re not recommending that people start taking steroids to help regulate their sleep cycles; the research, however, could inform jet lag future therapies.
Of course, all of these studies — and research on circadian rhythm in general — can help inform not only jetlag but also for other circadian-related sleep disorders, which can often be much more serious than the comparatively minor annoyance of adjusting to a new time zone.
Until these appear, however, we’re stuck with dealing with debilitating grogginess for the first few days of vacation. The good news is that even without these emerging therapies, jet lag is a relatively easy problem to overcome. Maintain as normal a schedule as possible, time your exposure to daylight, avoid long naps and excessive caffeine and your schedule should be back on track before you know it.