VERIFY | Yes, jet lag is worse if you travel east rather than west

WASHINGTON — Summer travelers and anyone heading across the country or overseas have a decision to make as soon as they depart: how to manage their sleep schedule to minimize jet lag.

Sleep on the plane? Stay up as long as possible? And does the right answer depend on the direction of travel?

We took the options straight to the experts to verify. 

QUESTION

Is it harder to recover from jet lag when traveling east compared to west?

SOURCES

ANSWER

Yes, scientists agree that traveling east is harder on the body than traveling west.

WHAT WE FOUND

Since the commercialization of air travel, passengers have tried to limit the effects of jet lag.

According to the CDC, jet lag is a temporary sleep disorder that “can affect your mood, your ability to concentrate, and your physical and mental performance.” Traveling across multiple time zones can affect the body’s circadian rhythm, the patterns the body follows over the course of a typical day. The Cleveland Clinic says altering a person’s circadian rhythm can negatively impact their hormones, digestive system, and body temperature, in addition to their sleep.

Researchers from the University of Maryland published a study in the journal "Chaos" in which they attempted to quantify whether traveling east or west created a greater impact on the body. They found that the brains of people traveling nine time zones east need nearly two weeks to recover from the initial jet lag, but people traveling the same distance west needed less than eight days. Likewise, someone flying across six time zones east would need more than eight days to recover, while someone flying across six time zones west would need fewer than six days. 

A 2010 article written by two scientists from Rush University adds that the human body’s natural circadian clock is often longer than 24 hours, so people have a natural tendency to want to stay up later each day and sleep later in the morning. That makes it easier for westbound travelers to adapt to the added hours given to them by flying across time zones.

The Cleveland Clinic says there is no guaranteed way to prevent jet lag. It recommends travelers adjust their eating and sleeping schedules ahead of time to minimize the impact, and move around while onboard the plane. After reaching their destination, travelers should drink lots of water and try to spend time in the sun, because those both encourage the body to be awake and alert. Avoiding new or unusual foods may help ease any digestive symptoms, as well. But the Cleveland Clinic says research is inconclusive about whether melatonin reduces the drowsiness associated with jet lag.