why do we get jet lag when we are stressed?

The Deep Dive

Jet lag, or desynchronosis, occurs when our internal biological clock, primarily governed by the suprachiasmatic nucleus (SCN) in the hypothalamus, is out of sync with the external light-dark cycle of a new time zone. The SCN is highly sensitive to light cues, which help regulate the release of hormones like melatonin (promoting sleep) and cortisol (promoting wakefulness). When we travel rapidly across multiple time zones, the SCN struggles to adjust instantly, as its rhythmic gene expression and neuronal activity are still aligned with the original time zone. Stress, whether from the travel itself, work pressures, or personal anxieties, triggers the release of stress hormones, particularly cortisol, from the adrenal glands. Elevated cortisol levels can directly impact the SCN and other peripheral clocks throughout the body, further disrupting the precise timing of circadian rhythms. This hormonal interference makes it harder for the body to suppress its old clock signals and adopt new ones, prolonging the period of desynchronization and intensifying jet lag symptoms such as fatigue, insomnia, digestive issues, and cognitive impairment. The body's fight-or-flight response, activated by stress, diverts energy from crucial regulatory processes, including the intricate task of resynchronizing the circadian system.

Why It Matters

Understanding the link between stress and jet lag is crucial for anyone who travels frequently or experiences significant time zone changes. Recognizing how psychological and physiological stress exacerbates symptoms allows individuals to implement strategies to mitigate its impact. By actively managing stress before, during, and after travel, people can potentially reduce the severity and duration of jet lag, leading to more productive business trips, more enjoyable vacations, and better overall health outcomes. This knowledge empowers travelers to prioritize relaxation, hydration, and mindful preparation, transforming what can be a debilitating experience into a more manageable one, thus improving well-being and performance across different time zones.

Common Misconceptions

One common misconception is that jet lag is simply extreme tiredness from lack of sleep. While sleep deprivation often accompanies jet lag, the core issue is a physiological desynchronization of the body's internal clock with the external environment, not just fatigue. You can be well-rested but still experience jet lag symptoms if your circadian rhythm is misaligned. Another myth is that alcohol helps you sleep better on a flight and reduces jet lag. In reality, alcohol disrupts sleep architecture, dehydrates the body, and can further interfere with circadian rhythm adjustment, ultimately worsening jet lag symptoms rather than alleviating them. It might induce drowsiness but it hinders restorative sleep.

Fun Facts

• The human body has peripheral clocks in almost every organ, which are influenced by the master clock in the brain but can also be affected by factors like meal times.
• Eastward travel generally causes worse jet lag than westward travel because it requires shortening the day, which is harder for the body to adjust to than lengthening it.