Older Adults Face Slower Circadian Readjustment, Intensifying Jet Lag

Travelers often find that the disruptive effects of jet lag become more pronounced with age, a phenomenon recently highlighted by Sebastian Siemiatkowski's query, "Why does jet lag get worse with age?" Scientific research indicates that the body's internal clock, known1 as the circadian rhythm, becomes less adaptable over time, making it harder for older individuals to synchronize with new time zones. This reduced flexibility contributes to more severe and prolonged symptoms of jet lag.

Jet lag, formally known as jet lag disorder, is a temporary sleep problem arising from a misalignment between a person's internal circadian clock and the local time of their destination. This disruption primarily occurs when rapidly crossing multiple time zones, throwing off natural sleep-wake cycles, hormone production, and other bodily functions. Symptoms can include daytime fatigue, insomnia, gastrointestinal issues, and impaired cognitive function.

As individuals age, their circadian rhythms undergo natural changes that diminish their ability to quickly adjust to new light-dark cycles. The body's tolerance to circadian phase misalignment decreases, meaning the internal clock struggles more to reset itself. This often translates to older adults requiring more recovery time for each time zone crossed compared to younger travelers.

Experts note that the pineal gland's production of melatonin, a hormone crucial for regulating sleep, can decrease with age, further impacting the body's capacity to adjust its sleep-wake cycle. While light exposure is a potent modifier of the circadian cycle, the timing and effectiveness of this re-synchronization mechanism can also be less efficient in older adults. Consequently, the duration and severity of jet lag symptoms tend to increase with advancing age.

Understanding these physiological changes can help older travelers prepare more effectively for transmeridian flights. Strategies such as gradual pre-adjustment of sleep schedules, strategic light exposure, and careful management of hydration and stimulants can help mitigate the effects, though the inherent biological challenges remain more significant than for younger individuals.