The science behind the toxic effects of chronic sleep deprivation

Our modern world is laced with slow poisons — things like tobacco, empty-calorie foods, and binge-watching platforms — that patiently shorten and dilute our lives over years of habitual indulgence.

History shows that society’s interaction with these poisons follows a predictable 5-stage process: uninhibited indulgence, risk recognition, risk communication, public concern, and policy action. As the example of smoking shows, this process can take decades to play out despite overwhelming evidence that billions of healthy life years are being lost.

Chronic sleep deprivation is one of the most potent poisons ever to enter this frustratingly slow process. Currently, it’s transitioning between the risk recognition and risk communication stages. We need to speed things up.

Today’s article aims to do just that by summarizing the scary details about the effects of sleep deprivation contained in Matthew Walker’s landmark book pictured below.

This daunting collection of science-backed findings certainly scared me to sleep. I hope it does the same for you.

Denial and Diagnosis

Sleep deprivation has two particularly pernicious qualities that help it proliferate through society:

1. Sleeping less for the sake of cramming more into each day is still seen as a sign of productivity and ambition that is viewed in a positive light.
2. Chronically sleep-deprived individuals believe they are performing optimally, even though objective tests definitively prove otherwise.

Here is a simple test to help you determine whether you’re chronically sleep-deprived and at risk of all the scary things outlined in the remainder of this article. To be safe, you must be:

1. Able to function optimally without the need for stimulants (e.g., coffee)
2. Unable to fall asleep before lunch (even if you tried)

If you are dependent on stimulants to get you through the day or if you regularly feel drowsy before lunch, you’re likely severely handicapping yourself by willfully taking the slow poison of chronic sleep deprivation.

Also, know that binge-sleeping over the weekend after a sleep-deprived week is of little use. Most of the adverse effects of sleep-deprivation are locked in after one or two bad nights and cannot be reversed by catch-up sleep.

If any of this applies to you, I sincerely hope the serious issues discussed below will motivate you to give sleep the priority it deserves.

Degenerative Disease

Chronic sleep deprivation could be the most underrated driver behind the global non-communicable disease burden, with strong causal links to heart disease, cancer, diabetes, and dementia.

Heart Disease

Sleep deprivation traps our sympathetic nervous system in a constant fight-or-flight mode. More stress hormones are released, increasing blood pressure, and weakening our arteries over time. Simultaneously, growth hormone concentrations decrease, inhibiting the body’s ability to heal the damaged arteries.

These effects of sleep deprivation increase the risk of heart disease by 45%, jumping to 200% for middle-aged individuals. Given that heart disease is by far the biggest killer on the planet, these are truly terrifying numbers.

Immunity and Cancer

Lack of sleep also compromises the immune system, increasing our chances of catching a virus and lowering our chances of fighting off malignant tumors. In these Corona times, you should know that sleep deprivation increases rhinovirus (common cold) infection rates from 18% to 50%.

More worryingly, cancer rates increase by 40% in individuals sleeping 6 hours or less, mainly due to a large decline in the natural killer cells responsible for destroying malignant elements in the body. In fact, tumor growth is enhanced by sleep deprivation, strongly increasing cancer risk.

Obesity and Diabetes

Sleep deprivation disrupts the hormonal balance responsible for appetite control, leading to significant weight gain. Furthermore, these unnatural food cravings are strongly biased towards all the wrong kinds of foods, caused by suppression of the higher centers of the brain responsible for moderating primitive cravings. To make matters worse, if a sleep-deprived individual is put on a strict diet, weight loss occurs mainly from lean muscle mass.

In addition, sleep deprivation makes our cells unresponsive to the message of insulin to absorb dangerous levels of glucose, putting healthy individuals in a pre-diabetic state. All these effects increase the risk of diabetes and other serious illnesses associated with obesity.

Alzheimer’s Disease

The connection between sleep deprivation and dementia is particularly troubling. Alzheimer’s disease is caused by plaque build-up in the brain. Deep sleep can counteract this development, but the plaque inhibits our brain’s ability to generate deep sleep. This causes a vicious cycle where inadequate sleep causes plaque build-up, which again causes inadequate sleep.

Once this cycle is underway, complete mental invalidity is inevitable. On the flipside, preliminary results have shown that effective treatment of sleep disorders can delay the onset of Alzheimer’s disease in high-risk patients by 5–10 years.

Genes and DNA

Sleep deprivation even distorts our genes. Researchers have identified 711 genes that are either abnormally revved up or suppressed by sleep deprivation. These effects are not yet well understood, but it is clear that chronic sleep deprivation is a potentially dangerous genetic engineering experiment being conducted on a global scale.

Furthermore, sleep deprivation causes telomere damage, resulting in faster aging and visibly older physical appearance.

Mental Health

As with physical health, the world’s major mental health problems are also closely linked with our chronic sleep deprivation epidemic.

Emotional Instability

In simple terms, a lack of sleep renders you bipolar. An underslept brain becomes emotionally unstable, swinging wildly between depression and euphoria. This effect is caused by a 60% amplification in the primitive fight-or-flight centers of the brain (amygdalae) combined with a suppression of the more evolved rational center (prefrontal cortex).

This causes all manner of problems, including violence, suicide, excessive risk-taking, and addiction. These emotionally unstable behaviors plague many sleep-deprived people in highly influential positions such as doctors, fund managers, politicians, and military personnel.

Sleep also enhances our ability to pick up on subtle emotional cues in waking life. Without it, we become unable to properly discern the emotional reactions of others, leading to serious miscommunication and conflict.

Stress and Anxiety

One of sleep’s most important functions in our highly-strung modern world is a soothing balm of free and effective overnight therapy. Specifically, sleep strips away the emotional edge from traumatic events, saving us tremendous amounts of unnecessary stress and anxiety.

This therapeutic effect originates from dreaming (REM) sleep where we process emotionally charged experiences in an environment devoid of noradrenaline (the brain’s version of adrenaline).

In fact, the potentially debilitating condition of PTSD is characterized by noradrenaline levels not receding during dream sleep, illustrating the terrible effects of forgoing this vital therapeutic benefit of sleep.

Cognitive Function

Scientific studies have proven that a lack of sleep degrades creativity, intelligence, motivation, effort, efficiency, effectiveness when working in groups, emotional stability, sociability, and honesty. It makes you wonder how many of society’s grave problems can be solved simply by all of us returning to natural sleeping patterns.

Memory

Sleep is essential for memory creation and retention. To use a computing analogy, it frees up the brain’s RAM by shifting memories to permanent storage so that there is space for new memories the next day. Thus, for effective memory function, we need good sleep the night before (to free up RAM) and after (to permanently store memories).

Sleep deprivation disrupts this memory processing, hampering our ability to recall distant memories and form new ones by 20–40%. After one night of insufficient sleep, the damage is done and that day’s memories are forever degraded. Students pulling all-nighters present a prominent example: Information is crammed into the brain’s RAM to pass the test, but the lack of sleep results in minimal longer-term retention, making the exam pointless.

Sleep also intelligently decides which memories to remember and which to forget. This avoids the buildup of useless memories that can interfere with the recall of useful memories. It also serves to soften painful memories.

Motor Memory

Memories related to physical coordination (e.g., playing a sport or musical instrument) are affected in a similar way. For example, musicians routinely report being able to play a piece much better after a good night of sleep.

Sports performance is also strongly improved by plentiful sleep. Most strikingly, the risk of sports injury declines from 73% to 18% when sleep is increased from 6 to 9 hours.

Creativity and Problem Solving

Sleep also plays an important role in the transition between learning and comprehension. It helps not only to store new information but also to connect it in novel ways (creativity). Dream sleep stimulates a kind of fuzzy-logic knowledge processing, leading to insights we could never achieve with wakeful rational thinking.

Experiments have shown a 15–35% increase in puzzle-solving ability after awakening from dream sleep. In addition, a set of strenuous tests with a hidden cheat code revealed that well-slept individuals found the cheat code 60% of the time versus only 20% of underslept individuals.

Creativity and problem solving are incredibly valuable in today’s world, making chronic sleep deprivation a severe handicap in the competitive job market. On a societal level, a universal lack of sleep significantly degrades our ability to solve our long list of global challenges.

Attractiveness and Reproduction

If you have dreams of attracting your soulmate and starting a family, you better make sure you get your beauty sleep.

Both sexes are clearly perceived as less attractive when in a sleep-deprived state. As mentioned earlier, a lack of sleep also promotes unhealthy eating habits that further detract from physical attractiveness. Furthermore, sleep deprivation dumbs you down and makes you emotionally volatile, clouding your personality. All these factors reduce your attractiveness as a mate.

For those planning to start a family, note that both men and women suffer lower fertility with sleep deprivation. If both partners are sleep-deprived, problems to conceive compound.

Accidents

Here’s something to think about: Driving your car after a night with only 4 hours of sleep is equally dangerous to driving when legally drunk, increasing your chances of causing an accident by 1150%.

Drowsy driving is therefore just as irresponsible as drunk driving. And the worst is that drowsy drivers believe they’re just fine.

There are two reasons why sleep deprivation makes us much more accident-prone: degraded cognitive performance and the occasional brief loss of consciousness, also known as a microsleep. It’s easy to imagine scenarios other than driving where reduced alertness or a brief bout of unconsciousness can endanger many lives.

Sleep Disorders

Even though the vast majority of sleep deprivation is the result of people simply giving themselves too little sleep opportunity, there can also be medical causes.

Insomnia is the most common of these. Often, people who think they have insomnia are just practicing poor sleep hygiene. However, if you are diligently following all the best sleep hygiene and sleep duration practices and still struggle to get enough sleep, insomnia may be the cause.

In these cases, it’s now well understood that sleeping pills should be the very last resort. They have a wide range of negative side effects and produce very poor quality sleep that fulfills little of sleep’s vital functionality. Cognitive-behavioral therapy for insomnia is a much better method.

Other sleep disorders include sleepwalking, narcolepsy, and fatal insomnia. Sleepwalking is mostly harmless, narcolepsy is a serious condition that requires dedicated management, and fatal insomnia is incurable, resulting in certain death. Fortunately, such serious sleep disorders are very rare.

Sweet Dreams!

There you have it. Sleep deprivation is bad for you in almost every way imaginable. Continuing to take this slow poison day after day will both shorten and dilute your life.

As stated earlier, the vast majority of sleep deprivation in our modern world is caused by people simply giving themselves insufficient sleep opportunity or practicing poor sleep hygiene. And the good news is that both these problems need little more than the right motivation to cure.

So please, buy Prof. Walker’s book. Read it with care. Then proceed to make the world a better place by spreading this vital sleep motivation far and wide!

The images in this article were custom-made by Janet Cloete.