Social jet lag could be the reason you're tired all the time
Do you set an alarm during the week and then snooze it on weekends to catch up on sleep? If so, chances are you suffer from social jet lag— a condition the affects 87% of office workers according to a study published in 2016.
What is social jet lag?
Social jet lag is the difference between the time you have to wake up and when you would wake up naturally. Like regular jet lag, it occurs when we shift our sleep-wake pattern between two different time zones: (1) one dictated by our work and social obligations and (2) the other by our internal circadian rhythm.
It's estimated that two-thirds of us experience one hour or more of social jet lag, and a third of us experience more than two hours1. That’s the equivalent to your work schedule running on Auckland time while your body clock is ticking on Sydney time, two hours behind.
How much social jet lag you experience depends on the gap between your social and internal clock. You can use our calculator to estimate how much social jet lag is affecting you.
Side effects of social jet lag
If you have ever suffered from normal jet lag, you know one of the most apparent symptoms is your chaotic sleeping pattern. It's common to feel tired all day and unable to sleep at night. The same is true for social jet lag, according to Till Roenneberg, professor of chronobiology at Ludwig-Maximilian University in Munich.
Unlike regular jet lag, which usually subsides in a few days as one acclimates to the new time zone, social jet lag can continue indefinitely if left unaddressed.
"Social jet lag promotes practically everything that's bad in our bodies," says Roenneberg.
Our internal clock influences more than just our sleep-wake cycle. It regulates over 60% of bodily functions. Constantly shifting your sleep time prevents this entire system from functioning optimally, which can result in:
A weakened immune system3–5
Reduced cognitive performance6,7
Greater chance of obesity8
Increased risk of cardiovascular disease9
Increased risk of metabolic disease10
What causes social jet lag?
Every cell in your body has its own clock, which is kept in synchrony with your master clock—the Suprachiasmatic Nucleolus (or SCN for short). Think of the SCN as the conductor of an orchestra. It makes sure your body's different systems—your immune system, metabolism, and sleep-wake cycle—work together harmoniously.
The timing of the circadian rhythm depends on daylight. When exposed to the specific wavelengths of blue light in sunlight, special receptors in our eyes send a ‘daytime’ signal to our body's master clock. But now we spend most of the day indoors with little natural light. Our master clock doesn’t receive a strong daytime cue.
The lighting in our homes and emitted by our devices also contain blue light. Although this light is insufficient during the day, during the evening it’s enough to signal to our circadian rhythm that the sun hasn’t set. As a result, our circadian rhythm can slowly de-synchronise from the solar day—resulting in social jet lag.
Mitigating social jet lag
Increasing your exposure to natural light during the day and limiting blue light at night can help your body clock naturally align with the day. Studies have shown that when people are sent camping – removing the influence of artificial light and exposing them to more daylight – they fall asleep about two hours earlier.
There's a movement of people rediscovering the benefit of living in alignment with the solar day. Some are making a conscious effort to spend more time outdoors during the day or reducing their exposure to blue light at night. Others are removing their curtains and waking up with the sunrise. Many report having more energy or that it ‘just feels right.11
But if you work indoors and you're not blessed with a window desk, getting back in sync is a whole lot easier said than done.
OSIN is a Kiwi start-up pioneering a new kind of light that brings the benefits of natural light into the built environment. Because at the end of the day, everyone deserves access to the light that supports their circadian rhythm.
- Roenneberg, T. & Merrow, M. The Circadian Clock and Human Health. Curr. Biol. 26, R432–R443 (2016).
- Social jetlag – are late nights and chaotic sleep patterns making you ill? the Guardian http://www.theguardian.com/lifeandstyle/2019/jan/21/social-jetlag-are-late-nights-and-chaotic-sleep-patterns-making-you-ill (2019).
- Scheiermann, C., Gibbs, J., Ince, L. & Loudon, A. Clocking in to immunity. Nat. Rev. Immunol. 18, 423–437 (2018).
- Spiegel, K. Effect of Sleep Deprivation on Response to Immunizaton. JAMA 288, 1471 (2002).
- Haspel, J. A. et al. Perfect timing: circadian rhythms, sleep, and immunity — an NIH workshop summary. JCI Insight 5, e131487 (2020).
- Smarr, B. L., Jennings, K. J., Driscoll, J. R. & Kriegsfeld, L. J. A time to remember: The role of circadian clocks in learning and memory. Behav. Neurosci. 128, 283–303 (2014).
- Okano, K., Kaczmarzyk, J. R., Dave, N., Gabrieli, J. D. E. & Grossman, J. C. Sleep quality, duration, and consistency are associated with better academic performance in college students. Npj Sci. Learn. 4, 16 (2019).
- Roenneberg, T., Allebrandt, K. V., Merrow, M. & Vetter, C. Social Jetlag and Obesity. Curr. Biol. 22, 939–943 (2012).
- Wong, P. M., Hasler, B. P., Kamarck, T. W., Muldoon, M. F. & Manuck, S. B. Social Jetlag, Chronotype, and Cardiometabolic Risk. J. Clin. Endocrinol. Metab. 100, 4612–4620 (2015).
- Scheer, F. A. J. L., Hilton, M. F., Mantzoros, C. S. & Shea, S. A. Adverse metabolic and cardiovascular consequences of circadian misalignment. Proc. Natl. Acad. Sci. 106, 4453–4458 (2009).
- Modern life of bright lights and devices confuse our brains, expert calls for smarter lighting. https://www.abc.net.au/news/2021-06-12/health-expert-wants-smarter-lighting-revolution-circadian-rhythm/100206566 (2021).