It takes more time for people to overcome jet lag when traveling east, and a group of scientists found out why. Sadly, there’s nothing much you can do about it.

People around the world usually report feeling kind of bad after traveling long distances by plane. Travelers often report having problems to sleep, headaches, irritability and fatigue among others. Worldwide, doctors receive patients presenting these symptoms all the time, and according to a group of scientists from the University of Maryland, there is not much they can do to help them.

Jet Lag
Scientists have found that jet lag is worse when traveling east. Credit:

The “disease” is commonly known as jet lag, and it occurs when a person travels through a lot of time zones in a short period of time. Before commercial flights were made available, fast-traveling was very difficult, and when people started using jet passenger aircraft, the problem surged. Hence, the name.

It might be a real problem for pilots, and airline crews, but for the regular Joe, it is just one of the downsides of taking a plane. Jet lag does not affect everybody in the same way, but as a rule of thumb, people usually advise to rest a day per each time zone crossed.

In the past, a couple of studies revealed that it took more time for people to recover from jet lag when they traveled eastward, but since the problem is not really that big, it was left like one of those things that bug the scientific community.

There is a biological clock inside every living thing

A group of specialists from the University of Maryland, led by Zhixin Lu, would not have it. They wanted to know the reason behind this difference, and they used mathematics to explain it successfully.

First, they started by identifying the problem within the human bodies, the internal clock that rules people’s physiology. After some research, they focused on the cells inside the suprachiasmatic nucleus which is located in the hypothalamus. Also known as SCN, this nucleus is tasked with regulating our circadian rhythms. It does so with the help of “slave oscillators” that synchronize many of the systems within the body.

Besides genetic and other individual factors, science has known that other external factors influence how SCN works. Sunlight, sleep patterns, alarms and many other things play a huge role the process. Things like physical alertness, hormone levels, and the immune function are affected by the circadian rhythm which is why people feel so affected when traveling.

Every living being on earth, from fungi to elephants, show signs of having an internal process based on a 24-hour basis.

Human’s internal clock does not work on a 24-hour basis

According to the researchers from the University of Maryland, human’s physiology is very affected by sunlight. In its absence, people’s internal clock will have an average 30 minutes natural delay. This varies from person to person, and it could have a delay up to an hour.

When someone travels westward, noon will arrive later than usual, and since our system has a natural delay, people will recover from jet lag in a more natural way. However, when travelling eastward, noon will come sooner which directly opposes our physiology. To put it in perspective, getting used to overeating is much simpler than getting used to fasting, for example, because it is natural for the body to satisfy hunger and urges.

The researchers hope their paper will encourage other specialists to investigate the field further, to try and find a possible solution for jet lag. Airlines have a lot of protocols to help their staff to cope with it, but science has not provided any permanent solution.

The team managed to create a mathematical model that tells how the circadian rhythm works, and it was included in the study. The paper was published on Chaos, an interdisciplinary journal of nonlinear science by the American Institute of Physics.

Source: AIP Scitation