When night becomes day

What is jet lag?

Jet lag refers to the temporary disruption of the body's natural rhythm caused by crossing multiple time zones. Our body follows a 24-hour rhythm influenced by light and darkness, which controls many bodily functions such as sleep and melatonin production. When we travel quickly between time zones, this rhythm may not adjust in time to the new schedule, resulting in an imbalance.

These symptoms are especially common after long-haul flights to distant countries. The body remains initially set to the original time zone, which causes adaptation difficulties. This affects not only sleep patterns but also food intake and hormone production. Jet lag is not a serious illness but a temporary disturbance that usually improves after a few days of adjustment.

Unlike on an aeroplane, where the body is exposed to a rapid time change, it can acclimatise better in slower modes of transport such as car or train, without typical jet lag symptoms. Short time shifts of up to about 90 minutes are also generally adjusted to without major problems.

How does jet lag present?

Jet lag appears as a variety of physical and emotional symptoms resulting from a disturbance of the body's natural sleep–wake rhythm. Sleep problems are particularly noticeable, either difficulty falling asleep or frequent waking at night. This often leads to persistent fatigue and a constant feeling of exhaustion during the day.

Concentration difficulties and reduced performance can also occur. Affected people find it hard to focus, which can cause problems both at work and in private life. Emotional symptoms such as irritability and mood swings are common. Some people also suffer from gastrointestinal complaints such as loss of appetite, constipation or diarrhoea.

Another common symptom is headache, usually caused by the body's adjustment process. In some cases there may also be dizziness or a general feeling of unwellness. The more time zones crossed, the stronger and longer the symptoms can be.

Generally, complaints disappear after an adjustment period of a few days to two weeks, once the body has adapted to the new rhythm. The severity and duration of symptoms can vary greatly between individuals.

In which direction is jet lag worse?

Flights west to east usually produce a more pronounced jet lag. This is because our circadian rhythm, which controls the natural sleep–wake cycle, finds it harder to adapt to shorter days. Flying east means "losing" time, which requires getting up and going to bed earlier. This adjustment to a shorter day is harder than flying west, where the body has extra hours to acclimatise to the new rhythm.

How does melatonin help with jet lag?

Melatonin can help the body adjust more quickly to a new time zone by supporting the natural sleep–wake rhythm. The hormone is produced in the pineal gland and plays a key role in regulating the circadian rhythm. Taking melatonin can stabilise the body's internal clock, which can be especially helpful after long-haul flights when time differences disrupt sleep patterns.

Studies suggest that melatonin may be useful for jet lag because it promotes sleep and makes it easier to fall asleep. Unlike synthetic sleeping pills, melatonin is not known to cause dependency or tolerance. Effectiveness may vary from person to person, and the exact dosage and optimal timing of intake are not yet definitively established.

How long does jet lag last?

Whether and how quickly a person adapts to a new time zone depends on various individual factors and can vary in duration. As a rule of thumb, about one day is needed for each hour of time difference to acclimatise to the new rhythm. For a six-hour shift, adjusting the biological clock may therefore take up to six days.

Adjustment time varies depending on age, health status and individual responsiveness. Younger and healthy people often adapt more quickly, while older people or those with sleep problems may need more time. The extent of travel strain (e.g. lack of sleep or multiple stopovers) can also prolong the time difference effects.

Can jet lag be avoided?

To avoid jet lag, it is advisable to prepare before the flight. One of the most important measures is the gradual adjustment of the sleep schedule to the destination time zone. If travelling east, try to go to bed and get up earlier in the days before the flight. For westbound flights, it helps to shift the sleep schedule by going to bed later and sleeping a bit longer.

During the flight it is recommended to set your watch to the destination time to prepare your internal clock for the new rhythm. It is important to drink plenty of water and avoid alcohol and caffeinated drinks, as these can negatively affect sleep. To keep the circulation going, get up and move regularly. If possible, adapt to the local sleep pattern at the destination to reduce jet lag.

How to overcome jet lag: useful tips

• Lemon balm tea has a calming effect and helps with falling asleep. Drink a cup of tea before bedtime to reduce restlessness and irritability.
• Choose light, easily digestible foods before bed that do not sit heavy in the stomach. Also avoid heavy, fatty meals as they can cause sleep disturbances.
• Don't eat too late. A light meal 2–3 hours before bedtime helps avoid disturbing sleep.
• If you fly east, favour carbohydrate-rich foods such as rice, pasta or potatoes. These promote sleepiness and can help counter jet lag.
• For westbound flights, protein-rich foods such as fish, chicken or legumes are better, as they do not promote sleep and help you stay awake during the day.
• After arrival, spend as much time as possible outdoors to make use of daylight. This helps adjust the natural sleep–wake rhythm quickly to the new time zone. Daylight can positively influence the sleep hormone and tune the body to the new daily rhythm. It is also important not to sleep immediately at night but to wait until the local bedtime.
• Rosemary oil can help boost concentration and fight fatigue. A few drops on the temples or wrists help stay alert.
• Melatonin can help you adapt faster to a new time zone. It is recommended to take a dose of melatonin about 30 minutes before bedtime.
• If you are tired after arrival, take a short nap of 20 to 30 minutes. Make sure not to sleep longer so as not to disrupt your night sleep.
• Sour cherry juice contains melatonin and may help regulate the sleep–wake rhythm. Drink a glass of juice daily after waking and before bedtime.
• Use a neck pillow for more comfort on the plane. It is also recommended to listen to relaxing music to promote sleep.
• Lavender oil has calming properties and can help you fall asleep more quickly. Apply it to the temples or use it as aromatherapy.
• Jet lag can also affect the gut. Eat probiotic foods such as yoghurt or sauerkraut to support your gut flora and reduce the effects of jet lag.

Jet lag can be unpleasant, but with the right strategies the body can quickly adapt to the new time zone. Patience and proper preparation help minimise the discomfort.