What are the effects of adjusting to a new time zone?

From the Guidelines

To adjust to a new time zone, it is crucial to prioritize strategies that minimize disruptions to the body's internal clock, with the most effective approach being to immediately adopt the local schedule for meals and sleep upon arrival, as supported by the latest evidence from the British Journal of Sports Medicine 1. When traveling across time zones, it is essential to consider the potential impact on the body's circadian rhythm. The severity of jet lag is proportional to the number of time zones crossed and the cumulative sleep loss, as noted in a study published in the British Journal of Sports Medicine 1. To mitigate this, several strategies can be employed:

• Gradually shifting the sleep schedule a few days before travel by going to bed and waking up one hour earlier or later (depending on the destination) each day
• Spending time outdoors in natural daylight, especially in the morning, to help reset the internal clock
• Staying hydrated and avoiding excessive caffeine and alcohol, which can disrupt sleep
• Taking short naps (20-30 minutes) if extremely tired, but avoiding long daytime sleeping
• Considering melatonin supplements (0.5-5mg) taken 30 minutes before the target bedtime at the destination to help reset the body clock, as suggested by a study in the Journal of Travel Medicine 1 It is also important to note that the timing of medication should be adapted to the local time at arrival, especially for patients with cognitive impairment or dementia, as discussed in a study published in the Journal of Travel Medicine 1. By prioritizing these strategies, individuals can minimize the negative consequences of jet lag and adjust to a new time zone more effectively. The key to successful adjustment is to realign the body's internal clock with the new time zone, allowing for the production of hormones like melatonin at appropriate times, as supported by the latest evidence from the British Journal of Sports Medicine 1.

From the Research

Adjusting to Time Zone

• Adjusting to a new time zone can be challenging, especially when traveling across multiple time zones.
• Jet lag is a common issue that affects air travelers, resulting from the body's internal rhythms being out of step with the day-night cycle at the destination 2, 3.
• Several studies have investigated the effectiveness of melatonin in preventing and treating jet lag, with results showing that it can be effective in reducing jet lag symptoms, particularly when taken close to the target bedtime at the destination 2, 3, 4.
• The optimal dosage of melatonin for jet lag prevention and treatment is between 0.5 and 5mg, with higher doses appearing to be no more effective 2, 3.
• In addition to melatonin, other non-pharmacological interventions such as light exposure, physical activity, and diet have been studied, but the evidence for their effectiveness is limited 5.
• A study comparing the effectiveness and tolerability of melatonin and zolpidem for the alleviation of jet lag found that zolpidem was the most effective treatment, particularly in facilitating sleep on night flights, but it was less well tolerated than melatonin alone 4.
• Another study discussed the approaches to the pharmacological management of jet lag, including the use of chronobiotic drugs, which can hasten adaptation of the circadian system, and drugs directly affecting alertness and sleep propensity 6.

Key Findings

• Melatonin is effective in reducing jet lag symptoms, particularly when taken close to the target bedtime at the destination 2, 3.
• The optimal dosage of melatonin for jet lag prevention and treatment is between 0.5 and 5mg 2, 3.
• Non-pharmacological interventions such as light exposure, physical activity, and diet may be helpful in reducing jet lag symptoms, but the evidence is limited 5.
• Zolpidem is an effective treatment for jet lag, particularly in facilitating sleep on night flights, but it may be less well tolerated than melatonin alone 4.

Considerations

• The timing of melatonin dose is important, as taking it at the wrong time can cause sleepiness and delay adaptation to local time 2, 3.
• The incidence of side effects from melatonin is low, but case reports suggest that people with epilepsy and patients taking warfarin may be at risk of harm 2, 3.
• Further research is needed to investigate the effects of melatonin in people with epilepsy and a possible interaction with warfarin 2, 3.