Written by Evien Cheng | Edited by Danica Kwan
Photo by Tim Gouw
A perfect vacation and horrible sleepless nights do not go hand in hand with each other, but it is a reality, especially for those long distance vacations. The term referring to poor sleeping times is jet lag, or circadian desynchrony. The human body has an inner clock called the circadian rhythm that runs for slightly over 24 hours [1], and traveling large distances can mess up this clock. As most would have experienced, the human body can naturally adjust to the time zone changes, but the process takes time and effects vary from person to person [2]. During this adjustment time, the inability to sleep, along with other uncomfortable symptoms, is what makes up the condition of jet lag. Jet lag is a common phenomenon travelers experience, and research has been done on the disorder to better understand and treat it.
Jet lag symptoms usually are recognized to be tiredness in the day, stomach discomfort, lack of focus, etc. [3]. The severity of these symptoms vary depending on a person’s age and how often they travel. Each person has an inherent tolerance against desynchronization of their circadian rhythm, but it decreases with age. Furthermore, studies have found that a person’s circadian clock resets around 57 minutes earlier when traveling eastward and 92 minutes later when westward [1]. Because the body can adjust faster to a longer day than a shorter one, symptoms tend to worsen when flying eastward than westward. Thus, the direction a person is traveling in also makes a difference.
Research has found that repeated jet lag could cause long-term consequences such as a higher risk of cancer, infertility, heart disease, etc. [4]. In fact, it was found that lighting cycles that affect the synchronization of internal circadian rhythm will shorten life expectancy in hamsters with heart disease by 11.3% [6]. Additionally, it is speculated that, when the body has to make readjustments to its circadian rhythm after experiencing jet lag, this shift has serious effects on one’s health. Due to this, some are seeking solutions to the health consequences of workers who experience jet lag on a regular basis.
One possible answer to the hidden dangers of jet lag is melatonin therapy. Melatonin is a hormone that causes sleep in the human body; it increases when the night is falling and decreases when it is morning. Research has found that people who took 5 mg/day of melatonin before an eight-hour flight and again four days after experienced significantly fewer jet lag symptoms [4]. Taking melatonin pills in the afternoon or the evening can promote sleep, while taking them in the early morning will delay sleep. Properly managing sleep cycles with the drug can quickly alleviate jet lag.
Research on jet lag has been progressive, but a larger, more comprehensive scope of research about the disorder has been limited. Most pharmaceutical companies see melatonin as a natural supplement instead of a potential pharmaceutical product. However, there are many people and organizations, such as military and government workers, who could benefit from an improved treatment of the disorder. [5]. It is crucial that more attention is paid to jet lag in order to promote healthy lifestyles and spreading awareness of jet lag as a whole.
References:
- Ambesh, P., Shetty, V., Ambesh, S., Gupta, S. S., Kamholz, S., & Wolf, L. (2018). Jet lag: Heuristics and therapeutics. Journal of family medicine and primary care, 7(3), 507–510. https://doi.org/10.4103/jfmpc.jfmpc_220_17
- Professional, C. C. medical. (n.d.). Jet lag: What is it, symptoms, how long does it last & treatment. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/12781-jet-lag
- Mayo Foundation for Medical Education and Research. (2022, November 19). Jet lag disorder. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/jet-lag/symptoms-causes/syc-20374027
- Choy, M., & Salbu, R. L. (2011). Jet lag: current and potential therapies. P & T : a peer-reviewed journal for formulary management, 36(4), 221–231.
- Herxheimer, A., & Waterhouse, J. (2003). The prevention and treatment of jet lag. BMJ (Clinical research ed.), 326(7384), 296–297. https://doi.org/10.1136/bmj.326.7384.296
- Davidson, A. J., Sellix, M. T., Daniel, J., Yamazaki, S., Menaker, M., & Block, G. D. (2006). Chronic jet-lag increases mortality in aged mice. Current biology : CB, 16(21), R914–R916. https://doi.org/10.1016/j.cub.2006.09.058