In a couple of weeks I’m flying to Europe, so I’ve been thinking about jet lag recently and how to overcome it.
I’ve been overseas a few times before and had a mixture of reactions. Occasionally jet lag knocks me out for a couple of days, whereas other times I barely feel it.
I hoped that by understanding more about why we get jet-lagged and how it affects us, I might find some strategies for adjusting to new time zones more quickly.
Essentially, jet lag is a series of symptoms that occur when our internal body clock is disrupted. We all have a built-in body clock. It’s a small group of cells made up of unique ‘body clock’ genes, called the suprachiasmatic nucleus, or SCN. These cells turn on and off and tell other parts of the body what time it is and what to do.
The body clock keeps us in tune with the pattern of day and night. It means we sleep at night, but also affects hunger, mood and blood pressure. 1
One of the main signals that help to regulate our body clocks is light, which helps us to reset our internal clocks each day to match the sun.
According to Dr. Smith L. Johnston, chief of the fatigue management team at NASA, it takes about a day for our bodies to shift just one time zone, so you can imagine why it often takes several days for us to adjust when we travel across several time zones at once.
A research team recently found out how jet lag works in mice, which should translate fairly well to humans, since all mammals run a very similar internal body clock process. Jet lag essentially comes from a process of “brakes” inside the brain that stop the body clock responding to light. The researchers found a huge number of genes were activated when the mice’s time zone was moved by six hours but a protein called SIK1 then “went round turning them all off again.” This protein acts like a brake—stopping the effects of light on the body clock.
The study found that reducing the function of SIK1 meant the mice could rapidly adjust to the six hour time shift, instead of battling through jet lag.
I didn’t think this made sense initially, but this BBC piece suggests that the brakes may be in place so that our body clocks aren’t affected by artificial light or moonlight, which could easily lead us to have an erratic body clock. Instead, the SIK1 protein aims to preserve the stability of our internal clock, making it a very slow process for us to adjust to a new time zone.
So we know how jet lag works now, but what about the way it affects us? Is it really such a bad thing to deal with jet lag as we slowly adjust to a new time zone?
Well, if you’re asking that question, you’ve never felt serious jet lag. Common symptoms involve fatigue, confusion and lack of awareness. Imagine those symptoms lasting for days as you grapple with the mental and emotional adjustment to your new surroundings.
As if that’s not bad enough, jet lag has also been shown to seriously disrupt our genes, throwing them off their normal rhythms. It’s also been shown to reduce neuron growth in the brain, decrease learning ability and memory capacity and induce stress.
You probably don’t want to put yourself through the symptoms of jet lag because it’s uncomfortable, if not because it can lead to negative health effects. There’s really only one way to avoid jet lag symptoms: adjust faster to your new time zone. Here are some of the ways to help your body do this (and some people say a mixture of methods is the best strategy):
To get started with this, it’s important to understand which way you’re traveling, as most people have a harder time adjusting when they travel east than west. When you travel east-to-west, your body clock needs to be delayed so you wake up and go to bed later. This is a lot easier for us to adjust to than advancing our body clock when we travel west-to-east.
Some studies have shown that attempting to advance or delay your body clock gradually before you travel can make the adjustment faster and easier on your body, reducing the effects of jet lag.
Helen Burgess, director of the biological rhythms research lab at Rush University Medical Center, tried adjusting her schedule prior to a trip from Chicago to Egypt. For several days before the trip, Burgess went to bed and woke up an hour earlier each day and took a low dose of melatonin in the early afternoons. Each morning she sought out bright light to help her body clock advance, and she said adjusting to the new time zone in Egypt was much easier than it would have been otherwise.
Controlling your light exposure seems to be the most in-depth process to avoid jet lag, but it may also be the most effective, according to some researchers. Dr. Smith L. Johnston, for instance, chief of the fatigue management team at NASA who I mentioned earlier, advocates this process as the best way to adjust faster to a new time zone.
Steven W. Lockley, a neuroscientist and consulting member of NASA’s fatigue management team, says that trying to adjust to your new time zone immediately is “exactly the wrong thing” to do. Adjusting to a change of multiple time zones, Lockley says, will only exhaust you if you attempt it right away:
What you need to do is to ease yourself into the new time zone by consciously manipulating your exposure to light.
To help your body clock reset to the new time zone, it’s important to seek out and avoid light at the right times of day. If you’re traveling east, you’ll want to advance your body clock, so seeking morning light and avoiding late afternoon light will help your body clock adjust to your earlier time zone. If you’re traveling west, you’d want to do the opposite.
If it sounds like too much effort to keep track of your light exposure, there’s actually an app for that. Entrain is an iOS app developed by researchers at the University of Michigan to help you track your light exposure. It uses mathematics to recommend light exposure at different times of the day to help you with the process of entrainment—i.e. adjusting to a new time zone.
I suggest this with a caveat that you should talk to a doctor first. Melatonin is the chemical your brain releases to make you sleepy, and it’s available over the counter, but it’s not regulated by the FDA and isn’t right for everyone.
However, one study found that a dose of 5mg of melatonin in the early evening helped participants to adjust to new time zones faster.
Dr. Lewy, of Oregon Health & Science, recommends taking a small dose at the local bedtime each night until your body clock catches up. If you’re traveling west, he suggests taking melatonin in the second half of the night instead.
If your trip is short and you’re not traveling over more than three time zones, you could be better off not adjusting at all. Jim Waterhouse, a professor of biological rhythms at Liverpool John Moores University often recommends staying on the same schedule you had at home rather than trying to adjust to local time if you’re not there for long. Three days or less, for instance, is barely enough time to adjust, so it may not be worth the effort. Waterhouse suggests keeping your watch set to the time at home and acting accordingly during your trip.
Lucky for me, I’m traveling from Australia, which means I get to go west and save the tricky west-to-east adjustment for when I travel back home. I also tend to go to bed early so moving my bedtime back a little each night shouldn’t be too much of an ask.
I’m looking forward to experimenting with avoiding and experiencing natural light at the right times to see if I can adjust any faster than usual. If I can beat my first ever jet lag experience of sleeping for 17 hours straight, I think I’ll be happy.