Hand up if you have never at least once experienced the symptoms of jet lag!
The “Jet Lag Syndrome” includes a set of disorders affecting travellers that go through multiple time zones, as is generally the case during an intercontinental flight. The human body is synchronised on a 24-hour sleep-wake cycle, which is what our personal daily routines are based on.
What we define as our “inner clock” is scientifically termed circadian rhythm. As circadian rhythm is quite rigorous, disorders and discomfort such as those associated with the jet lag may be suffered when it is upset.
Circadian rhythm is a complex mechanism which paces our biological rhythms in harmony with the environment around us.
In 2017, scientists Jeffrey C. Hall, Michael Rosbash and Michael W. Young were awarded the Nobel Prize for Physiology and Medicine for their discovery of the molecular mechanisms that control circadian rhythm. They succeeded in demonstrating that our “inner clock” is a purely genetic matter. They isolated the concerned genes and studied the molecular mechanisms underlying their functioning in order to have an in-depth understanding of the way in which the biological clock in each human being works.
This discovery offered the opportunity to identify three different types of major rhythms, otherwise known as “chronotypes”:
What is jet lag exactly?
Jet lag symptoms occur when our circadian rhythm is upset by a series of events which require adaptation to new sleep and wake times. This causes a set of physiological reactions which include alterations in hormone secretion, changes in the arterial pressure and variations in some blood flow parameters, such as increased levels of cortisol, i.e. the stress hormone.
The intensity of the symptoms is not the same for everybody: it changes according to age, routine hours of sleep and a person’s chronotype.
Curiosity: jet lag tends to be more impactful when travelling East or West, and not North to South and vice versa. Symptoms are also more acute when travelling from West to East. This is due to the fact that our body finds it easier to extend the circadian rhythm rather than to shorten it.
Jet lag symptoms
The main problems connected with the jet lag typically include sleep disorders such as insomnia, sleepiness during the day or the feeling of not having had enough rest when you wake up.
These symptoms are associated to a set of side disorders, including:
The duration of these symptoms varies according to a combination of factors:
Jet lag prevention and treatment
Before you set out for a long journey, you may resort to some useful tricks to help prevent or reduce the jet lag syndrome.
If you are tired once you get to destination … well, travelling is quite tiring.