After taking a few long-haul flights from Europe to Australia during the last 7 years I often wondered whether jet-lag was a real thing or whether we just made ourselves believe that we would feel pretty rough after being stuck that long in a small flying box breathing the same recycled air for up to 15 hours.
When I was young did I get jet leg? I can’t remember. The first time I flew from Australia to Europe I was 13 and I can’t say I noticed feeling tired, but I was most likely fairly excited and preoccupied by other more interesting things!
So is Jet-lag just in our heads? Or is it a physical thing the body experiences? And can we prevent it?
For years, jet lag was considered merely a state of mind but studies have since shown that it does actually result from an imbalance in our body’s natural “biological clock” caused by traveling to different time zones.
Our bodies work on a 24-hour cycle called “Circadian Rhythms”…This is why I start yawning at 10 minutes to 10pm and I wake up promptly at 7am without an alarm (note that some peoples clock is more persistent that others), and while my body clock is fairly set in its way I know some people who can push the snooze on their body clock and it doesn’t seem to notice.
This circadian rhythm flexibility (or lack there of) does have an impact on jet lag!
If you are a “morning person” who wakes up promptly it is most likely that you find it difficult to sleep in past 9am, and for those “morning people” jet-lag is probably going to hit you a lot worse!
The “circadian rhythms” in our body are measured by the distinct rise and fall of body temperature, plasma levels of certain hormones and other biological conditions. All of these are influenced by our exposure to sunlight and help determine when we sleep and when we wake.
When traveling to a new time zone, our circadian rhythms are slow to adjust and remain on their original biological schedule for several days. This results in our bodies telling us it is time to sleep, when it’s actually the middle of the afternoon, or it makes us want to stay awake when it is late at night. This experience is known as jet lag.
Cristina Ruscitto (PhD) has done extensive research on this topic after completing her PhD in Health Psychology, at the University of Surrey in England.
Last year Cristina led two major studies into how to reduce jet lag: 1) Ruscitto, C., & Ogden, J. (2017). The impact of an implementation intention to improve mealtimes and reduce jet lag in long-haul cabin crew, Psychology and Health, 32(1), 61-77, and 2) Ruscitto, C., & Ogden, J. (2017). Predicting jet lag in long-haul cabin crew: The role of illness cognitions and behaviour. Psychology and Health, 32(9), 1055-1081.
Cristina says she chose this topic for her research because of her previous work as a member of a long-haul cabin crew (experienced jet lag and sleep disruption) together with her interest in Health Psychology.
“The study particularly showed the importance of mealtimes for alleviating jet lag in long-haul crew. There is plenty of evidence in animal research that feeding times affect the body clock but this evidence in humans is limited: e.g. a study found that late eaters lost less weight than early eaters. In my study, the group of crew who made a meal plan (to eat regularly, breakfast lunch and dinner) before a long-haul trip, had reduced jet lag symptoms after a long-haul trip when compared to a control group (no meal plan). The results showed that planning ahead your meal times by eating in line with the local time help adjust more quickly and reduce jet lag levels.”
So basically, if you are flying to the Uk from America you should put your self onto the UK meal and sleep time as soon as possible.
“These findings are new because traditional countermeasures look at improving sleep or taking medication to deal with jet lag but this study shows that ‘when’ you eat can also help reduce jet lag levels.
This is particularly useful if the person in question is unable to take sleep aids as in the case of a crew member, who must be working during the flight.”
However, as I mentioned above not everyone suffers from jet-lag, at least not to the same degree.
“Not everyone suffers from jet lag,” says Cristina. “This depends on different factors, but one of the most important is a person’s chronotype, whether one is an ‘evening’ or ‘morning’ person.
Evening people, or people who can easily sleep in past noon, cope much better with jet-lag because they find it easy to prolong sleep.
“Their sleep is more flexible (e.g. they can extend their sleep) and therefore can adapt more easily than morning people following time zone transitions.” adds Cristina.
So how then can meal times help us adjust more quickly?
Well of course when we eat our blood sugar levels spike, and our blood sugars plays a role in regulating our body clock.
So if you are planning a long journey, and you are a morning person like me, the best you can do is get onto the new sleeping schedule as soon as possible by adjusting your mealtimes accordingly!