By Cassie Jewell, M.Ed., LPC
According to the American Academy of Sleep Medicine, about 10% of Americans struggle with chronic insomnia and up to 35% of Americans experience insomnia at least occasionally. I’m part of the 10%. I’ve spent countless nights tossing and turning, dreading the obnoxious sound of “quantum bells” (my cell phone alarm) as daylight slowly creeps in. Due to this, I’ve done quite a bit of research on the subject. (And as a clinician, it’s important for me to know the relationship between restful sleep and mental health so I can educate my clients.)
Sleep recharges us; it makes it possible for us to remember what we learned throughout the day.
We all know that basic sleep hygiene is essential (i.e. having a regular sleep schedule, refraining from watching TV or reading in bed, avoiding alcohol before bedtime, etc.) And if you struggle with insomnia, you’ve probably heard of sleep medications and supplements like Ambien, trazodone, or melatonin. We also know how vital sleep is to health and wellness. Sleep significantly impacts mood, energy levels, and overall well-being. Sleep recharges us; it makes it possible for us to remember what we learned throughout the day.
Knowing how crucial sleep is for both physical and mental fitness, I set out to explore what happens when we don’t get enough. What exactly does a lack of sleep do to a person? I sifted through the research to learn more about the impact of sleep deprivation. This post explores how sleep deprivation affects physical health, perceptions, memory, and critical thinking.
SLEEP AND YOUR PHYSICAL HEALTH
Sleep deprivation is associated with signs of aging
Sleep deprivation has been linked to aging skin. One study found that poor-quality sleepers had more fine lines, uneven pigmentation, and reduced elasticity.
It makes sense that chronic sleep deprivation is associated with signs of aging; sleep is needed for overall rejuvenation (mind and body), which includes skin cell renewal. For smooth and supple skin, high-quality sleep is essential.
A 2016 study looked at the relationship between sleep characteristics and body size/weight. Snoring was associated with having a higher BMI, a larger waist, and more body fat. (It should be noted that snoring doesn’t cause obesity; the two are simply related.)
Poor sleep quality and shorter durations of sleep were linked to larger body size and more body fat. The relationship between sleep and obesity is further explored in the next few paragraphs.
Sleep deprivation is related to weight loss and appetite
If you’re dieting, you’re more likely to lose body fat when you’re getting adequate sleep. Researchers studied participants who slept for either an average of seven and a half hours or five and a quarter hours per night over a 14-day period. Calorie consumption was the same; participants lost similar amounts of weight. However, when participants slept more, they lost more body fat; in fact, about half of the weight they lost was fat. Sleep-deprived participants lost only a pound of fat; the other five pounds were fat-free body mass. Furthermore, it was found that sleep helps with appetite control; this is due to ghrelin, a hormone that stimulates appetite and promotes fat storage. Sleep-deprived participants had higher levels of ghrelin.
If you’re watching what you eat, incorporate healthy sleep habits to maximize your efforts; adequate sleep is needed for optimal weight loss.
Sleep affects our food choices
Other studies have examined specific the ways sleep deprivation affects food choices and calorie intake. Sleep deprivation is associated with especially poor food choices the day following poor-quality or no sleep. One study found that sleep deprivation led to strong cravings for junk food. The researchers measured increased activity in the part of the brain that responds to rewards, but decreased activity in the “decision-making” part of the brain. Study participants choose unhealthy items (i.e. pizza, donuts) over fruits and vegetables.
Another study looked at total calorie intake; sleep-deprived participants consumed an extra 385 calories per day. They also ate higher-fat foods. Additionally, researchers found that a sleep-deprived person purchased items that were higher in calories when grocery shopping.
A 2016 study looked at the relationship between sleep deprivation and the consumption of high-calorie, sugar-sweetened caffeinated beverages in a sample of 18,000 adults. It was found that adults who averaged less than five hours of sleep per night were more likely to consume sugary drinks like soda or energy drinks than their well-rested counterparts. The researchers weren’t able to determine whether drinking caffeinated beverages caused people to sleep less or whether being sleep-deprived caused people to crave more sugar and caffeine; it’s likely that both are true.
Without high-quality sleep, it’s difficult to lose body fat.
Regarding obesity, sleep deprivation plays a significant role. A lack of sleep causes us to feel hungry. We crave junk foods and consume more calories. At the same time, sleep deprivation promotes fat storage while decreasing our energy levels. Without high-quality sleep, it’s difficult to lose body fat.
If you struggle with chronic insomnia, make an active decision to make healthy eating a habit; you’ll be less likely to submit to your cravings. Visit the grocery store only when you’re well-rested. Know that you may not feel like exercising; practice determination. Be mindful to counter some of the health risks associated with sleep deprivation.
Sleep deprivation is related to heart disease, hypertension, and stroke (especially if you’re a woman)
In addition to obesity, sleep deprivation is associated with heart disease, high blood pressure, diabetes, and stroke. A lack of sleep takes a toll on the heart. In a recent study, researchers looked at 24-hour shift workers. It was found that sleep deprivation led to a significant increase in cardiac contractility, blood pressure, and heart rate. Furthermore, study participants experienced thyroid changes and an increase in cortisol (the stress hormone).
Research also indicates that chronic sleep deprivation and disrupted sleep are linked to an increased risk of developing or dying from coronary heart disease or stroke. Diabetes and hypertension are associated with sleep deprivation as well.
A lack of sleep may impact women more than men. Researchers found that women who got less than eight hours of sleep per night were at a higher risk of heart disease and other heart-related problems when compared to men who got the same amount of sleep.
Chronic sleep deprivation is related to reduced immune function
Have you ever noticed that you heal slowly or get sick more often when you’re sleep deprived? According to research, chronic sleep deprivation is associated with reduced immune function. If you’re not regularly getting at least six to seven hours of sleep, you’re more susceptible to illness. Your immune system won’t be as effective at eliminating viruses and bacterial infections.
Sleep even affects your bones. One study found that chronic sleep deprivation was associated with a loss of bone mass (in rats, at least). The rats underwent sleep restriction measures for three months. A lack of sleep led to significant decreases in bone density, volume, and thickness.
SLEEP AND YOUR BRAIN
Sleep deprivation is associated with increased pain sensitivity
The first part of this post examined sleep’s impact on physical health; the next half will explore how sleep affects the mind, including the way we sense and perceive the world around us. Research indicates that sleep deprivation and/or disruption increase sensitivity to pain. Interestingly, in one study, stimulants like caffeine had the ability to “normalize” the pain sensation (meaning it would feel the way it would with adequate sleep).
Sleep and chronic pain seem to be intricately connected, but the relationship is not fully understood; up to 88% of individuals with chronic pain report sleep issues and nearly 50% of individuals with insomnia have chronic pain..
In addition to the sensation of touch, sleep deprivation affects the perception of sound. A lack of sleep impairs central auditory processing (CAP). CAP is crucial for aspects of hearing such as language comprehension, identifying sounds, and recognizing patterns.
In one study, participants took a longer time identifying sounds after being deprived of sleep for 24 hours. It appeared there was a “transfer delay” (from hearing to identifying and then interpreting). To be effective, CAP requires alertness and concentration.
Sleep deprivation affects the formation of memories
We know that sleep deprivation causes cognitive impairment; the brain can only store so much information before it must recalibrate. During sleep, memories are encoded; the brain “consolidates” memories by strengthening them and transforming them from short-term into long-term memories. Without sleep, long-term memories can’t form. Short-term memories are lost and/or altered. Even procedural memories are impacted by sleep deprivation. A lack of sleep leads to forgetfulness and an inability to retain new information.
Sleep affects the way we interpret emotions
Sleep deprivation impairs your ability to interpret facial expressions. A recent study found that a lack of sleep made it difficult for participants to recognize the facial expressions of happiness or sadness. Interestingly, the ability to detect anger, fear, surprise and disgust was not affected. This suggests we’re biologically wired to recognize the emotions related to survival. The researchers hypothesized that the brain preserves functions that perceive life-threatening stimuli while sacrificing functions associated with empathy, bonding, and friendship.
“Real life” implications: If you’re majorly sleep-deprived, you could misinterpret the intentions of others, negatively impacting relationships with co-workers, family, friends, and others. Furthermore, you could read people wrong or miss important social cues; you might not respond appropriately or you could seem lacking in empathy.
When someone is sleep deprived, they’re slower to adopt another’s perspective
In addition to perception and memory formation, sleep deprivation impacts decision-making skills and thoughts, including the ability to accurately assess a situation.
If you have chronic insomnia, you might experience interpersonal problems.
In 2015, researchers hypothesized that sleep deprivation would impair the capacity to recognize sarcasm. Study results didn’t support the hypothesis, but the research generated an unexpected outcome. It was found that someone who was sleep-deprived was slower to adopt another person’s perspective. Implications? If you have chronic insomnia, you might experience interpersonal problems.
Sleep deprivation affects our moral judgment
Sleep deprivation affects moral judgment. In one study, participants were sleep deprived (awake for 53 continuous hours) and then faced with moral dilemmas. They had difficulty solving the dilemmas and making appropriate judgments. Other studies support this as well; a lack of sleep is related to decreased moral awareness. When you’re faced with a tough decision, especially one that involves ethics or morals, be sure to get adequate sleep. You can’t always trust your moral compass.
Sleep deprivation is linked to impaired decision making
Moral decisions are taxing if you’re sleep deprived… the opposite is true with risky ones. Sleep deprivation alters areas in the brain that assess positive and negative outcomes; sensitivity to rewards is enhanced while attention to negative consequences is diminished.
If you haven’t slept, tough decisions can wait.
Researchers found that when gambling, sleep-deprived individuals were more optimistic about their odds of winning. Another study found that sleep deprivation made it difficult for study participants to come to a quick decision when pressured. Sleep-deprived participants also made more mistakes. If you haven’t slept, tough decisions can wait.
A lack of sleep affects optimism
If you’re not getting enough sleep, you could lose your ability to remain positive-minded. Research indicates that individuals with insomnia have lower rates of self-esteem and optimism. In 2017, researchers found that sleep-deprived study participants were less likely to focus on positive stimuli. An inability to think positively is also a symptom of depression.
A lack of sleep can lead to schizophrenia-like symptoms
Sleep deprivation can lead to perceptual distortions, cognitive disorganization, and anhedonia (an inability to feel pleasure).In a 2014 study, participants experienced psychosis after staying awake for 24 hours. The sleep-deprived individuals reported attention deficits and being more sensitive to light, color, and brightness. They exhibited disorganized speech, which is a common symptom of schizophrenia. Participants also reported an altered sense of time and smell. Some of them actually believed they were able to read thoughts; others noticed an altered body perception. Implications? If you miss a night (or two) of sleep, don’t be surprised when you hear voices or when your reality is somewhat altered.
In conclusion, sleep deprivation, especially when it’s chronic, is detrimental to your health. Based on my review of the research, poor-quality sleep can adversely impact your skin, your weight, your cardiovascular system, your immune system, and your bones. (It should be noted that I barely skimmed the surface of an immense body of scientific data on sleep.)
Sleep is also related to brain health. Sleep deprivation impairs sensory perceptions, memory formation, the ability to assess your environment, moral awareness, critical thinking skills, and mood. Sleep deprivation can even induce psychosis.
If you’re like me (the one out of 10 Americans with chronic insomnia), in addition to practicing good sleep hygiene, go ahead and Google “CBT for sleep.” Research suggests that for some, CBT is more effective and longer-lasting than sleep medication. Do a little bit of research. CBT is not a quick fix for insomnia, but it’s worth a try; and your health and wellness are definitely worth it!
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