Opting for a hearty breakfast over a late-night snack may enhance sleep quality while traveling. Exploring distant destinations promises a plethora of unique experiences, yet it often comes with the unwelcome companion of jet lag. Adjusting to a different time zone frequently leads to fatigue, sleep disturbances, and a variety of challenges that can overshadow the excitement of a new adventure.
Jet lag arises from a misalignment between the body’s internal circadian system, its internal clock, and the external environment. Scientists began to realize in the early 21st century that the body possesses multiple internal clocks, each calibrated differently, and when these clocks fall out of sync, jet lag-like symptoms can occur. This phenomenon becomes more pronounced with age.
In a study published in Chaos by AIP Publishing, researchers from Northwestern University and the Santa Fe Institute developed a theoretical model to investigate how multiple internal clocks interact with one another, especially in the context of aging and disruptions like jet lag.
Recent research has demonstrated that circadian clocks exist in nearly every cell and tissue in the body. Each clock relies on specific cues for calibration; for example, the brain’s clock depends on sunlight, while peripheral organs synchronize with meal times.
Author Yitong Huang explained, “Conflicting signals, such as warm weather during a short photoperiod or nighttime eating—eating when your brain is about to rest—can confuse internal clocks and cause desynchrony.”
Our understanding of how these various internal clocks influence one another remains limited, partly due to the complexity of dealing with multiple clocks. Many studies typically focus on one particular time cue or a single clock. Huang noted, “Important gaps remain in our understanding of the synchronization of multiple clocks under conflicting time cues.”
Huang and her colleagues adopted a different approach by constructing a mathematical framework that accounts for the intricate interplay between these systems. Their model features two populations of interconnected oscillators that mimic the natural rhythms of circadian cycles. Each oscillator influences the others while adapting to unique external cues.
Using this model, the researchers explored how such a coupled system could be disrupted and identified factors that exacerbate the disruption. They discovered that common age-related symptoms, such as weakened signals between circadian clocks and reduced sensitivity to light, render the system more vulnerable to disruptions and slower to recover.
Moreover, they stumbled upon a novel method to expedite recovery from jet lag and similar disruptions. According to their findings, the key to achieving better sleep lies in the timing of meals. “Having a larger meal in the early morning of the new time zone can help overcome jet lag,” Huang suggested. “Constantly shifting meal schedules or having a meal at night is discouraged, as it can lead to misalignment between internal clocks.”
The authors intend to delve into the other side of the equation and pinpoint the factors that contribute to more resilient internal clocks. Such insights could yield recommendations for preventing jet lag or maintaining a healthy circadian system as individuals age.
Reference: “A minimal model of peripheral clocks reveals differential circadian re-entrainment in aging” by Yitong Huang, Yuanzhao Zhang, and Rosemary Braun, 5 September 2023, Chaos. DOI: 10.1063/5.0157524.