*This post was written in August.
Writing this after very little sleep due to the current heatwave* and the fact few UK homes have air conditioning, I’m acutely aware of the restorative power of sleep and how challenging the day is when you don’t feel rested.
I’m also guilty, like many others, of relegating sleep to the sidelines in favour of another hour of Netflix, a final scroll of TikTok, or staying up simply because it’s been a good day, and I don’t want it to end. I never fail to suffer the next day. I also never seem to learn.
But there are more serious consequences to a lack of sleep.
The Committee on Sleep Medicine and Research highlights that disasters including the nuclear reactor meltdowns at Three Mile Island and Chernobyl, the Exxon Valdez oil tanker, the Gas Leak In Bhopal, India that killed 15,000 people, and the Challenger disaster (discussed later) have been partially attributed to sleep loss.
Why We Sleep by Matthew Walker
There has been increased interest in the restorative power of sleep in recent years, particularly with the release in 2017 of Professor Matthew Walker’s book Why We Sleep: The New Science of Sleep and Dreams.
Walker, a neuroscientist and sleep expert, delves into the science behind sleep, its various stages, and the profound impact it has on our health and well-being. He stresses that sleep is not an optional luxury but a fundamental necessity for optimal functioning.
“Within the brain, sleep enriches a diversity of functions, including our ability to learn, memorise, and make logical decisions and choices. Benevolently servicing our psychological health, sleep recalibrates our emotional brain circuits, allowing us to navigate next-day social and psychological challenges with cool-headed composure.”
Circadian rhythms
Walker also introduces the topic of circadian rhythms, defined by Kalmbach, et al (2017) as cyclical changes in cellular, molecular, and biological processes which are driven by an internal “master clock” and repeated approximately once every 24 hours.
Kalmbach, et al (2017) explain that “circadian rhythms play a central role in the regulation of many aspects of physiological processes, including sleep–wake cycles”. However, the timing of these rhythms is not the same for everyone.
Owls and Larks
Many will be familiar with the terms lark and owls. These fall at either ends of the circadian rhythmicity continuum.
Larks have ‘early chronotypes.’ They prefer to wake up early and feel most productive during this time, whereas owls have ‘later chronotypes.’ They prefer to wake up much later in the day and typically feel most active and motivated in the late evening.
Employment schedules and school start times
Walker points out that much of modern life, such as employment schedules and school start times, are strongly biased toward early start times. These punish owls and favour larks, which can impact job performance and overall wellbeing.
“Most unfortunately, owls are more chronically sleep-deprived, having to wake up with the larks, but not being able to fall asleep until far later in the evening. Owls are thus often forced to burn the proverbial candle at both ends.”
Physical consequences of sleep deprivation
The effects of sleep deprivation are wide-ranging, affecting nearly every aspect of physical health. Insufficient sleep weakens the immune system, leaving the body more prone to infections and slowing recovery from illness.
Chronic sleep deprivation increases the risk of serious conditions like cardiovascular disease, diabetes, obesity, and Alzheimer’s due to disruptions in immune function, hormone levels, and glucose metabolism.
Hormonal imbalances, particularly in cortisol, leptin, and ghrelin, can heighten stress, cravings, and weight gain.
Sleep deprivation also impairs motor skills, coordination, and strength, negatively impacting physical performance and increasing vulnerability to pain.
Long-term lack of sleep accelerates aging, leading to skin issues such as wrinkles and a dull complexion.
As well as this, sleep-deprived individuals are at higher risk for car accidents and workplace incidents due to reduced concentration and increased likelihood of microsleeps. Addressing sleep disruptions is essential for maintaining overall health and well-being.
Impact on mental health
Sleep deprivation has a significant impact on mental health, contributing to stress, irritability, anxiety, and low mood. Insufficient sleep impairs emotional regulation, making it difficult to process experiences and manage emotions, which can lead to mood swings and strained social interactions.
Chronic sleep loss is linked to a higher risk of psychiatric conditions, including depression, anxiety, and even suicidality.
Sleep is essential for cognitive function, aiding in memory consolidation, learning, and problem-solving. Without adequate rest, mental clarity, focus, and decision-making suffer, impairing our ability to handle complex tasks and reducing productivity.
The relationship between sleep and mental health is bidirectional; poor mental health can disrupt sleep, while lack of sleep can exacerbate mental health issues. Prioritising quality sleep is crucial for maintaining emotional balance, cognitive sharpness, and resilience in daily life.
Performance deficits
According to the Committee on Sleep Medicine and Research, the performance deficits associated with sleep loss include the ability to pay attention, to be vigilant, and to react quickly, as well as and other measures of cognition, including memory and complex decision making.
Tragic consequences: the Challenger Space Shuttle disaster
The official report into the Challenger Space Shuttle disaster found that fatigue on the part of console operators in the launch control centre at Kennedy Space Centre meant error messages were misinterpreted (NASA).
The operators were on eleven hours into their third day of working 12-hour night shifts. Akerstedt (1985) found that night shifts and changing work patterns produce sleep loss and fatigue by disrupting workers’ Circadian rhythms. Operator fatigue is cited as one of the major factors contributing to this incident.
Key managers involved in a teleconference between launch parties, where postponing the mission could have been discussed, had several days of irregular working hours and insufficient sleep in the lead-up to launch day. The decision to postpone should have been based on engineering judgments but sleep loss resulted in judgement errors.
One night of bad sleep
Walker writes that the physical and mental impairments caused by just one night of bad sleep far exceeds those caused by an equivalent absence of food or exercise.
“It is difficult to imagine any other state— natural or medically manipulated—that affords a more powerful redressing of physical and mental health at every level of analysis.”
Research concludes that “sleep is the single most effective thing we can do to reset our brain and body health each day – Mother Nature’s best effort yet at contra-death”.
“The shorter your sleep, the shorter your life span.”
A fundamental pillar of health
Sleep is a fundamental pillar of health that we often overlook. Its restorative power affects every aspect of our lives, from physical health and cognitive function to emotional well-being.
By prioritising sleep, we can unlock the secret to a healthier, more balanced life. Embrace the power of rest, and watch as it transforms your well-being, energy levels, and overall quality of life. Sleep is not a luxury – it’s a necessity. We need to treat it as such.
Sources
Kalmbach, D.A., Schneider, L.D., Cheung, J., Bertrand, S.J., Kariharan, T., Pack, A.I. and Gehrman, P.R., 2017. Genetic basis of chronotype in humans: insights from three landmark GWAS. Sleep, 40(2), zsw048.
NASA: Report of the Presidential Commission on the Space Shuttle Challenger Accident.
Walker, M., 2017. Why we sleep: The new science of sleep and dreams. Penguin UK.
