Benefits of Good Sleep
“If you want to build a ship, don’t drum up the men to gather wood, divide the work and give orders. Teach them to yearn for the vast and endless sea.”
In this section we aim to build a yearning for the life you could have by making the effort to improve your sleep habits. Sleep is especially helpful in three areas of your health: interpersonal, physical, and mental.
Interpersonal Health
Enhanced Interpersonal Relationships. The rested version of you keeps you at your best self in your relationships. Sleep loss causes social withdrawal and loneliness (Simon, 2018), whereas better sleep helps a person regulate the ups and downs of emotions more effectively and reduces irritability (Whiting et al, 2023). This results in the version of you that your friends want to be around.
Improved Emotional Function: A good case study for the importance of sleep for interpersonal wellbeing is REM sleep. Incredibly, time spent during this stage of sleep is the only time that norepinephrine, one of your body’s main stress hormones, is not found in the brain. Many have even theorized that dreams exist to give our brains a low-risk avenue for processing, practicing, and preparing for stressful situations, including social ones. We can wake in the morning prepared to solve problems with a renewed sense of emotional clarity and peace about people and things that may normally trouble us. This may be the reason why the phrase “you’d better sleep on it” can be found across almost all languages and cultures. When we don’t get enough sleep, it’s easy to feel the opposite effect: we wake up distressed and our problems seem just as big as the day before. REM sleep truly is the most affordable and accessible source of therapy!
Physical Health
“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.”
Overall Health. Research consistently finds optimal sleep is associated with physical health. Chronically sleeping less than 5-6 hours or more than 10 hours is associated with cardiovascular disease, diabetes, high blood pressure and obesity (Grandner et al., 2014) as well as stroke and frequent mental distress (Liu et al., 2013). In a meta analysis looking at 70,000 elderly individuals, those who slept both too short and too long were more likely to die (Gallicchio & Kalesan, 2009). Even small amounts of sleep loss can have major consequences to physical health. Take daylight savings time for example. When an hour of sleep is lost in March, there is more than a 20% increase in the rate of heart attacks among the general public. When an hour of sleep is gained in November, there is a 21% decrease in the rate of heart attacks. A similar profile is seen in car accidents, deaths by drug overdose, and even suicide attempts (Osborne-Christensen, 2022). Evidently, small losses of sleep can be consequential to physical health.
Weight Control. Sleep plays a crucial role in regulating body weight, with poor sleep leading to significant hormonal changes that increase appetite and promote fat storage. Leptin, which suppresses hunger, decreases by 18%, while ghrelin, which stimulates hunger, rises by 28% after just two days of sleep loss (Spiegel et al., 2004). Additionally, endocannabinoid levels skyrocket with inadequate sleep, further increasing appetite. Poor sleep also disrupts insulin function, encouraging fat storage and making weight gain more likely.
As stated by Dr. Matt Walker in his podcast, sleep deprivation also increases cravings for unhealthy foods, raising the desire for sugary, high-carb, and salty foods by 33%, 30%, and 45%, respectively. Impaired decision-making due to poor sleep further leads to impulsive eating and reduced motivation for physical activity ((Greer et al., 2013). Additionally, sleep loss hinders weight loss efforts, as individuals who sleep less while dieting lose 55% less fat and experience a 60% greater loss of muscle mass (Nedeltcheva et al., 2010). These effects create a cycle where poor sleep leads to weight gain, making it harder to lose weight later.
Overall, people with insufficient sleep often gain weight even when eating what feels like a normal amount of food. While diet and exercise are key to managing weight, proper sleep is an essential yet often overlooked factor.
Improved Immune Function. With insufficient sleep over just a week, gene expression in over 700 genes throughout the body is negatively changed. The genes that showed decreased activity were those involved in immune function, weakening the body's defense mechanisms. Meanwhile, the genes that became more active were linked to tumor growth, increased inflammation, and elevated stress levels—factors that are also connected to a higher risk of cardiovascular disease. Furthermore, just one night of sleep being cut from a solid 8 hours down to a meager 4 hours is enough to decrease activity of natural killer cells in your body by 70%, which work to recognize cells that are either foreign to your body, such as pathogens, or cells that have mutated, such as cancer cells. Lastly, your body’s production of cytokines--important proteins for preventing and fighting sickness--goes way down when you don’t get enough sleep. The same goes for infection-fighting antibodies. Altogether, those who sleep less then 7 hours a night are three times more likely to get the common cold. If you’re in the business of not getting sick, you may want to consider a full night of rest!
Mental Health
Improved Decision-Making and Impulse Control. Lack of sleep impairs judgment and self-control, making it harder to resist temptations and properly assess risks. Just think of the thousands of car accidents caused by sleepy drivers each year. A tired brain causes more traffic collisions, workplace accidents, surgical and medical mistakes, and a loss of work productivity that has an unmeasurable effect on the wider community (Institute of Medicine, 2006). Anderson and Platten (2011) found that sleep deprived people were more likely to overuse substances or to overeat due to reduced inhibitory control. Good sleep allows the proper functioning of the prefrontal cortex responsible for decision making, self control and even ethical behavior (Barnes et al., 2011).
Improved Attention and Focus. Adequate sleep enhances the brain's ability to maintain concentration and avoid distractions. A well rested person performs faster and more accurately in tasks where sustained attention is required (Lim & Dinges, 2010). It also enhances problem-solving, creativity, and decision-making skills.
Increased Neuroplasticity and Memory. Sleep fosters the brain's ability to form and reorganize synaptic connections, essential for learning and adaptation. One particularly potent neurotransmitter, brain derived neurotrophic factor (BDNF) is boosted during sleep (Raven et al., 2019). This neurotransmitter was nicknamed “miracle grow” for brain cells by author John Ratey. BDNF is crucial for synaptic plasticity and for growing new brain cells. The brain also consolidates memories and strengthens synaptic connections while you sleep, particularly in slow-wave and REM stages, making your brain a more efficient tool for learning (Tononi & Cirelli, 2014). On the other hand, chronic sleep restriction has been shown to actually change our brain structure, shrinking the hippocampus, which is the brain’s central memory hub (Kreutzmann et. al 2015). If you’d like to learn more about the relationship between sleep and memory, check out the video here (optional).
Lower Risk of Depression - Sufficient sleep reduces the risk of developing an array of mental health issues such as anxiety and depression because key brain chemicals are regulated during sleep, including cortisol, the stress hormone, and serotonin, which is also known as the “happy hormone.” As such, insufficient sleep increases the risk of mental health disorders such as depression and suicidality. Sufficient sleep, on the other hand, makes you happier. Not only is sleep disturbance associated with depression, but usually precedes it; people with insomnia are twice as likely to develop depression than those without (Li et al., 2016). It’s worth repeating: You are twice as likely to develop depression with insufficient sleep.
Less Anxiety - Anxiety disorders and poor sleep are strongly correlated (Goldstein et al, 2013). One study used brain imaging to measure the activity in the amygdala and insula in sleep deprived subjects. These are the areas of the brain responsible for anticipating and responding to threats. They found hyper-reactivity in these areas in those that were sleep deprived. Furthermore, those subjects who were already prone to anxiety were more negatively affected than those who weren’t (Goldstein et al., 2013). So, if you tend to be on the anxious side, sufficient sleep will be essential to keep the brain feeling safe.
Other Mental Health Issues. There is a bidirectional relationship with mental health and sleep, which means that sleep disturbances can exacerbate the symptoms of mental disorders, and poor mental health adversely affects sleep (Baglioni et al., 2016). This effect is observed in an array of mental conditions. Up to 90% of those with PTSD have sleep disturbances (Gehrman, 2020). Bipolar disorder and post-traumatic stress disorder (PTSD) include symptoms of disruptions in circadian rhythms and poor sleep quality (van Someren, 2020). About 50–80% of those with psychiatric disorders also experience chronic sleep problems. Compare those numbers to only 10–18% in the general population (Harvey et al., 2011).
Comparable to Traditional Therapy. Research by Harvey et al. (2017) found that addressing sleep issues in clients who had mental health disorders produced similar therapeutic results compared to conventional psychotherapy. These sleep interventions have been found to significantly reduce psychological issues such as anxiety and depression and overall well being (van Straten et al., 2018). These and other studies indicate that a). Insufficient sleep may be a driving force behind many mental illnesses and b). Intervening on sleep issues may be a vital component of mental health services.
“The best bridge between despair and hope is a good night’s sleep.
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After learning about the benefits of good sleep, can you begin to see why we think sleeping well can quite literally change your life? As Dr. Matt Walker said “there is simply no aspect of your wellness that can retreat at the sign of sleep deprivation and get away unscathed.” Take a moment to think about some of the benefits that good sleep has on your physical and mental wellbeing. What parts of your life are hard right now? Can getting better sleep help improve any of those areas? How else can better sleep improve your wellbeing? How willing are you to make changes in order to enjoy these benefits?