10 jet lag myths debunked

There are many persistent misconceptions about how to cure jet lag. It's time to replace guessing with real science.

Travelers are constantly bombarded with misguided anecdotal advice from non-experts on how to alleviate jet lag, resulting in many persistent misconceptions about jet lag and how to alleviate it. The problem is that few in the travel industry understand the underlying science of jet lag, and as a result, their advice is based on the wrong assumptions. It's time to replace the myths with tested and validated circadian science.

The science of jet lag

Most life on earth is adapted to the daily light/dark cycle caused by the rotation of our planet. We have a 24-hour circadian clock, located in the suprachiasmatic nucleus (SCN) in the brain, that helps us manage the regular rhythm of our day. Jet lag is caused when the sleep/wake and light/dark cycle shift too quickly for our circadian clock to keep up.

Surprising to many, light is the most important time cue for resetting your circadian clock. Managing when to see light and when to avoid light is critical to adapting to new time zones quickly. The right light exposure at the right time can significantly accelerate your adaptation. Seeing light at the wrong time — as often recommended by non-experts — will make your jet lag worse.

In addition to timed light exposure, the right type and dose of melatonin, at the right time, can help you shift faster and sleep better as you are transitioning between time zones. If you take melatonin without timing your light exposure correctly, it will not be as effective and you will not adapt to your new time zone any faster.

Jet lag myths

Any jet lag ‘solution’ that does not have light and light avoidance as the central planks of the advice will not help you adapt to new time zones faster. Some advice may aim at improving sleep or reducing sleepiness, but this is not addressing the underlying cause of jet lag — a little like treating the symptoms of an illness without addressing the underlying disease. This may seem to help in the short-term but is not the most efficient or effective solution. 

Given that appropriately timed light exposure and light avoidance are vital to alleviating jet lag, many of the common ‘tips’ are either ineffective or may even make your jet lag worse. 

Jet lag myth #1 – “Sleep as much as possible on the plane”

Sleep equals dark as far as the circadian clock is concerned so if you sleep at a time when you should be seeing light, you will shift your clock in the wrong direction and make jet lag worse. Advice focused only on sleep, without resetting the circadian clock, assumes that insomnia and sleepiness are the only symptoms of jet lag, which is not the case. Sleep timing should be scheduled as part of the overall light-dark exposure plan designed to reset the circadian clock as quickly as possible.

Jet lag myth #2 – “Use sleep medications”

Sleep meds might knock you out on the flight, or help you fall asleep faster in the hotel, but they don’t shift the circadian clock and could lead you to miss seeing light at the right time, which is the real solution to jet lag. Sleeping medications are not necessary if light-dark exposure is timed properly to reset the clock — once the clock is reset, you should be able to sleep at your normal time.

Jet lag myth #3 – “Use massages or acupuncture”

Neither massage nor acupuncture have been shown to reset the circadian clock and therefore cannot address the underlying cause of jet lag. While they may make you feel relaxed, they will not help you adapt quicker.

Jet lag myth #4 – “Use a special diet or fast”

Many claims have been made about diets or fasting being able to reset the clock. These claims are based on studies of nocturnal (night-active) rodents which cannot easily be translated to (day-active) humans. Food is a weak time cue for resetting the clock in the brain and there is currently no accepted method for using food — or fasting — for resetting circadian rhythms.

While advice on what and when to eat may be helpful in avoiding the metabolic consequences of jet lag, caused by eating at the wrong biological time, it will not alleviate the underlying cause.

In addition to the circadian clock in our brain, we also have clocks in peripheral tissues and organs such as the heart, liver, lungs, pancreas, and kidneys which help us keep local time under the control of the “master” circadian clock — a little like individual players in an orchestra under the supervision of the conductor. Based on animal work, these clocks are likely to be more sensitive to food than the circadian clock in the brain clock, and meal timing can theoretically be used to help reset them more quickly. The problem is that no-one knows how to reset peripheral clocks in humans as the research is still ongoing. Advice that claims to know how to reset peripheral clocks in humans in not based in science.

Jet lag myth #5 – “Go for that 7am run”

Like food, exercise is also a very weak circadian synchronizer so it doesn’t help reset your circadian clock. The time at which you exercise may also lead you to see light at the wrong time and shift your clock in the wrong direction, making your jet lag worse. Exercise needs to be timed as part of the overall light-dark exposure plan.

Jet lag myth #6 – “Trust airplane lighting”

Colorful LED lighting on new airplanes looks great, and some airlines even claim to be giving you light that helps jet lag, but they nearly always deliver the wrong light at the wrong time, or deliver the wrong intensity or spectrum of light. The lighting and meal schedules on most flights are not timed to help you reduce jet lag and in fact are often timed incorrectly and may make your jet lag worse.

Jet lag myth #7 – “Travel in business class”

Many travelers choose to spend money on business class specifically to reduce the symptoms of jet lag. They believe sleeping on the flight will make them ready to work as soon as they land. Yet, the sleep and lighting schedules on flights are not personalized to address the underlying cause of jet lag, and often makes jet lag worse. Business class is great, but only if you know when to sleep to ensure the appropriate light-dark exposure to maximize the circadian resetting.

Jet lag myth #8 – “Stay at 5-star hotels”

As with business class travel, investing in high class hotels with good mattresses, choices of pillows and ‘sleep programs’ can be a great benefit, but they won’t do any good without knowing when to sleep and when to see and avoid light exposure.

Jet lag myth #9 – “Stay hydrated”

Although drinking water and staying properly hydrated is important for your health and will make you feel good, it won't shift the circadian clock and will not alleviate jet lag.

Jet lag myth "#10 – “Battle through sleepiness with a lot of caffeine”

While caffeine does not reset the circadian clock, it can be a useful tool to help manage jet lag and ensure that you stay awake at the right time to see light. The trick with caffeine is ‘little and often’ to help maintain alertness at the right time while minimizing the negative effects of caffeine on sleep. Caffeine stays in your circulation a long time — caffeine taken even early in the morning will affect your sleep that night. Many people think that caffeine does not affect them, but it does — they just don’t realize it!

Jet lag treatment

The challenge is to find the right timing for when to see and avoid light, take melatonin, sleep or nap, and use caffeine effectively. Solving this challenge is deceptively complicated, not intuitive, and can only be determined based on your sleep pattern, chronotype, itinerary, and personal constraints. With the Timeshifter jet lag app, you can create personalized jet lag plans with all of this in mind.

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