This is the second post on a feature I am including in my blog titled “Psych Facts”, which I am going to try and post on once a month. Last month’s topic was about the psychological impact of reading fiction, and this month I chose the circadian rhythm because it’s become relevant in my quarantine life.
I recently got a job at a grocery store, and since the coronavirus is going around I figured working overnights was my best chance at not getting the virus. It also so happens that at the time I was deciding to start working the graveyard shift I was also learning about the body’s circadian rhythm. Turns out, it’s pretty important.
So what is the circadian rhythm?
The circadian rhythm is your body’s internal clock that determines when hormones are released and how much. It controls functions such as temperature, mood, coordination, and attention [4]. What’s most interesting is that there are certain times of day that are best for learning and movement, which I didn’t expect to be controlled by the circadian rhythm. For example, the afternoon is when your body reaches its peak coordination level and fastest reaction time.
Each individual’s circadian rhythm is controlled by a combination of internal and external factors. Not every circadian rhythm will match the figure above, but most will look similar because of light from the sun. Light is one of the most important external signals for the circadian rhythm, which means that day duration and seasonal factors can disrupt the circadian rhythm. Lifestyle choices like when you go fall asleep, when you wake up, caffeine and screen time can also affect the body’s natural clock as well as hereditary factors [3].
Changing your rhythm
The circadian rhythm is hard to change, and continuous disruptions can lead to chronic health issues such as metabolic obesity, cardiovascular diseases, and cancer. Not to mention, sleep deprivation leading to decreased immune functions. And yes… there’s more. A healthy rhythm is important for emotional regulation and memory. Not getting enough sleep or getting sleep at irregular times has been associated with depression and decreased executive functioning of the brain [1][2][3][4].
There is evidence showing that people who work shifts after 10 pm or before 6 am have decreased cognitive function. Memory and intelligence tests taken by people who are working the night shift or who worked the night shift in the past have lower results than people who have shifts during the day [1][3]. Before I get too far, there are some studies that show no correlation between working night shifts and decreased cognitive function. Factors like age, alcohol, smoking, and stress also impact the brain and should be considered [4]. (I should also probably mention here that correlation does not always mean causation).
In reality, not everyone is affected the same by changes to their schedule [3]. Pulling one all-nighter or deciding to work night shifts is not the end of personal health. All of the studies I read that showed a negative correlation between the night shift and cognitive ability were done with middle-aged to elderly populations when people are already at a higher risk for neurodegeneration and cardiovascular diseases. I still decided to work during the night, so I will share some tricks that have made it easier on my body.
My Experience
My goal while transitioning to the graveyard shift was to shift my circadian rhythm instead of disrupting it.
The first thing I did before starting my new job was to start going to bed as late as possible. My work schedule was 10 pm to 6 am, so I knew that on a workday I probably wouldn’t get to bed until 6:30 am or 7 am. To reduce the negative impacts of disruption of the circadian rhythm, a complete sleep schedule change isn’t actually necessary [4]. On nights off I decided to stay away until 3 am, so there were only a few hours difference between work nights and nights off.
Besides changing the times I slept, I also decided to change a few bad habits. I put down all screens during the last hour before bed. Light from phone or TV screens signals the mind that it is still daytime and can reduce the brain’s secretion of melatonin, which is super important for sleep regulation [3]. I always sleep better if I am not looking at a screen before bed, so I know this works. Lastly, I put a sheet over my window so my room stayed dark and stopped drinking coffee. Yup, I did it. Caffein does help with staying awake, but it can also cause problems with sleep [5]. I was already putting my body through hell, so I figured I should at least give it a caffeine break.
My plan ended up working pretty well, but the first couple of weeks were hard. I sometimes slept up to 12 hours a day and had trouble falling asleep and staying focused on school work. My energy level all around was lower than normal, and, honestly, since I’m stuck at home all day there wasn’t much motivation to get out of bed…. Those were dark days. It has gotten much better recently, and setting alarms definitely helps. The difficult part is just getting out of bed after the alarm goes off. Also remembering which days I have work. Do days of the week still exist?
Because the circadian rhythm is so fundamental in our daily lives and long term health, I think everyone should be aware of it. Sometimes the problem isn’t just getting enough sleep; it’s getting enough sleep on a consistent schedule.
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Copyright (c) Yassine Mrabet.
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Works Cited
[1] Benedict, Christian, Eva Lindberg, Helgi B. Schioth, Lars Lind, Olga E. Titova, and Solve Elmstahl. “Association Between Shift Work History and Performance On the Trail Making Test In Middle-Aged and Elderly Humans: the EpiHealth Study”. Neurobiology of Aging vol. 45, September 2016. Pg 23-29.
[2] Born, Jan, Horst-Lorenz Fehm, Kirsten Hansen, Matthias Molle, and Tanja Lange, “Effects of Sleep and Circadian Rhythm on Human Circulating Immune Cells.” The Journal of Immunology. June 1997. March 06, 2020.
[3] Farhud, Dariush, and Zahra Aryan. “Circadian Rhythm, Lifestyle and Health: A Narrative Review.” Iranian Journal of Public Health. August 2018. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6123576/.
[4] Price, Michael. “The Risks of Night Work.” Monitor on Psychology, American Psychological Association, Jan. 2011, www.apa.org/monitor/2011/01/night-work
[5] Sleep Advisor Last Updated On March 6. “How Shift Work Affects the Circadian Rhythm (Graveyard Shift) – 7 Issues.” The Sleep Advisor. March 06, 2020. https://www.sleepadvisor.org/how-shift-work-affects-circadian-rhythm/.
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