Why Is Sleep Important?
Sleep is a basic psychological need that is necessary for our survival, like drinking water and eating without it we would die. That’s why knowing how poor sleep can negatively affect your health and life is important.
Just as hunger and thirst, sleep reverses sleepiness, with its homeostatic properties. Our physiological processes have a daily rhythm that parallels the 24-hour sleep-wake cycle.
If one cycle or rhythm is disrupted it directly affects the other.
There is big importance in getting a sufficient amount of sleep as the disturbance of it correlates with increased risk of developing adverse health conditions or reactions such as cardiovascular diseases, depression, diabetes, etc.
Disturbance of sleep meaning short/long sleep duration and/or poor sleep quality.
Now, poor sleep does not only come from physiological factors as mentioned earlier. Sleep is strongly affected by various psychosocial factors, stress, and daily routines. Further contributors to poor sleep are socioeconomic status, age, even race.
For this reason, the impact of sleep loss/disturbance reaches beyond the immediate realm of just making an individual sleepy; it can impact the entire biological entity either directly or indirectly.
Mounting evidence supports the hypothesis that chronically restricted and disrupted sleep has significant health consequences. By dysregulating immune and endocrine pathways, sleep may contribute to an increased risk of inflammatory mediated diseases, including cardiovascular disease, diabetes, metabolic syndrome, and depression.
The immune system monitors our internal environment and is our main protector against diseases and illness.
The products of the immune system are greatly controlling our current and future health. That is why direct and long-term protection against diseases as well as health maintenance is jeopardized if there are any imbalances in the production of those products.
There is a sufficient amount of evidence that supports the role of adequate sleep amount and quality for maintaining an effective and functional immune system. Therefore the lack of sleep is correlated with increased levels of “bad” products.
That is why it is important to discuss the negative consequences of poor sleep on our immune system.
When sleep is disrupted it can be considered as a physiological stressor through activating certain immune processes in our body.
It is important to be said that it is not acute yet chronic activations that contribute to diseases. That means only if the sleep is poor during prolonged periods that imbalances in the immune system are noticeable.
Epidemiologic data shows that poor sleep correlates to higher levels of inflammation in the body. Increased inflammation levels are directly associated with a decreased functional capacity to remove invading bacteria and toxins, suggesting an impaired ability to defend against infection.
The endocrine system is our hormone regulator.
There are several important hormones for regulating a well-functioning sleep-wake cycle.
One of those hormones is melatonin which is produced by the pineal gland. Melatonin is circadian-rhythm driven and it can be said that its primary function is to regulate and assist in the shift of wake-sleep cycles. That means that it greatly influences our internal clock.
It is especially helpful in disturbed circadian rhythms, caused by jetlag for example. Supplementation with melatonin is a popular and in most cases effective way to battle the trouble of falling asleep. That being said, melatonin may not always be helpful.
Different lifestyles and dietary habits greatly affect the quality of sleep.
Humans have a so-called fight or flight system which is called the sympathetic nervous system, SNS, that directly interacts with the endocrine system.
The SNS is a part of our autonomic nervous system, ANS, that regulates autonomic functions such as breathing.
Now SNS regulates certain substances such as adrenaline. Those substances are of a big importance in regulation of energy and different cardiovascular functions.
Sleep deprivation leads to increased activation of the SNS and elevation of the substances it regulates. Those substances, such as adrenaline, are keeping us on the edge and create unfavorable changes in our ANS when increased over prolonged periods. Those changes can have negative effects on our cardiac health and metabolism.
That is why understanding the consequences of sleep deprivation is important.
Stress Causes Poor Sleep
When under stress a certain hormone called cortisol is released in increased amounts.
Usually, that increase is only under a short period, enabling our body to respond adequately to stress. In normal amounts, cortisol is beneficial for us.
It plays a big role in our metabolism as it controls blood sugar levels. Cortisol has anti-inflammatory effects, controls the body’s water balance, and influences blood pressure.
Sleep deprivation is directly correlated with increased production of cortisol and vice versa.An excess amount of cortisol increases the amount of NREM, bad, sleep and decreases REM, good, sleep.
When sleep is poor and cortisol levels are high under prolonged periods the cortisol receptors get desensitized. That can lead to the state of chronic stress as well as a disturbance in earlier mentioned functions. Those functions being inflammation, blood pressure, etc.
Cognitive health is negatively affected by poor sleep. Sleep deprivation has been associated with being a risk factor in developing severe somatic and mental disorders.
The affected functions being attention, verbal learning, memory, and different executive functions. Those findings have been identified in both experimental and studied environments. Furthermore, evidence suggests that even prolonged duration of sleep is linked to worse cognitive performance.
Association between sleep quantity and cognitive performance takes an inverse U-shape. Meaning, there is a certain amount of sleep needed for optimizing peak cognitive performance. Too little and too much sleep are detrimental.
Decline in cognitive performance in domains such as reasoning, spatial visualization and memory is a normal occurrence.
Although, even if the level of decline is individualized, certain sleeping durations have worse effects in mentioned domains. For example, short 3-4h and long >10h sleep has been associated with impaired memory in older adults.
Accidents & Poor Sleep
Lack of sleep causes lowered alertness, inattention, and delayed reaction. The scientific evidence to prove that accidents are the cause of sleepiness is low. That is because those events are hard to directly study.
That being the case, some of the biggest accidents occurred due to inadequate human response. It is even more than coincidental that those errors occurred when individuals were in sleep deprivation.
It has been shown that individuals sleeping less than 7 hours during 24h period have higher chances of being involved in car accidents. The risk gets higher the less you sleep. In the U.S. one in five adults sleeps chronically less than 7 hours even if the recommendation is 7-9h of sleep. That being said, driver drowsiness was involved in 7 percent of all motor vehicles and 16 percent of all fatal crashes.
Let’s Battle Poor Sleep Together
Lack of sleep can be detrimental to our health and life. Getting the appropriate amount of sleep between 7 and 9 hours can not only elevate but also save your life. Make sure to reflect on your sleeping patterns and take the next big step towards improving your health.
We can do this together!