Apr 7, 2017

Definition of Sleep

What exactly is sleep? Why does sleep deprivation has adverse effects on your health? Why is sleep important? This are some of the questions that we seek to answer as we discuss about sleep and its effect on your health. Sleep can be defined as a condition of the body and mind during which the eyes are closed, the nervous system is relatively inactive, conscience is suspended and postural muscles are relaxed.

There are several definitions of sleep but most of them describe the state of the body during sleep. This can be attributed to the fact that sleep is a process. In order to make the most out of your sleep, sleep quality, length as well as time should be optimum.

The Role Played by Sleep in Staying Healthy?

Have you ever tried to stay awake for hours on end? You will start feeling drowsy, your hand-eye coordination becomes poor and you feel extremely fatigued. These are typical examples of sleep deprivation symptoms. Sleep plays a crucial role in your health as it helps your body as well as the brain to relax and rejuvenate. Did you know that sleep deprivation related road accidents claims an estimated 1500 deaths in the United States each year?

The process of sleep can be categorized into two categories; rapid eye movement and non-rapid eye movement states (REM and non-REM). During the non-REM state, body temperatures drops, heart rate slows down and sleep is light. During this stage, the body is preparing to enter into deep sleep and it can easily be interrupted by external stimuli.

As you fall into deep sleep, some regions of the brain show reduced activity. In this stage, the body is rejuvenating and trying to mend wear and tear in cells and tissues. This anabolic state also allows the body to strengthen the immune system. This state is referred to as the REM state and it is during this state that dreaming takes place.

How Many Hours of Sleep Do You Need?

If you are in the age bracket of 18-64 years, then you need 7 to 9 hours of sleep in one day. If you are older than 64 years, you should ideally sleep for 7-8 hours a day according to the National Sleep Foundation. As for children and teenagers, they should sleep for 12 to 10 hours a day.

importance of sleep

There are two body systems that regulate your sleep cycle; they include the circadian biological clock and the sleep/wake homeostasis. These two systems help us maintain a balance between the hours we are asleep and awake. It is therefore important to maintain a uniform sleep cycle.

The circadian and biological clocks are closely connected and they play an important role in determining sleep patterns in an individual. According to the National General Medical Sciences (NIH); the biological clock co-ordinates with suprachiasmatic nucleus (a group of nerve cells located in the hypothalamus) to control as well as monitor sleep/wake cycles.

Melatonin is the name of the sleep hormone that is released by the brain. The release of melatonin is influenced by the circadian rhythms that regulate the internal clock of an individual. Oversleeping or sleep deprivation has adverse effects on the health of an individual and is a decisive factor in determining the longevity of life. This is because sleep quality determines nervous system performance, memory and overall performance.

The Relationship Between Sleep, Stress and Blood Pressure

Insufficient sleep adversely affects the cardiovascular function as it alters the circadian rhythm according to American Heart Association. Additionally, sleep restriction reduces heart rate vagal activity and variability which interferes with normal functioning of the heart. Lack of enough sleep increases the levels of hormone norepinephrine which is a stress hormone.

Sleep and Your Heart Health

According to a study published by researchers at the University of Chicago, low sleep quality may lead to calcification of the coronary artery. Another study showed that men who went to bed before midnight had healthier arteries as compared to those who slept late.

Sleep and Inflammation

Lack of enough sleep triggers inflammatory process which leads to increased levels of C-reactive protein in the blood. In a study published in the American Journal of Epidemiology, reduced sleep caused the levels of C-reactive proteins and interleuin-6 to double within a period of 5 years. This condition makes the body to become prone to diseases especially cardiovascular ailments and depression.

How Does Sleep Affect Memory and Performance

Lack of enough sleep has extremely adverse effects on one’s mental performance. As mentioned earlier, the brain rejuvenates and relaxes during sleep. It follows that lack of enough sleep hampers cognitive functions and leads to impaired memory. Additionally, sleep deprivation causes attention lapses and decreased cognitive performance. Due to sleep deprivation, response to stimuli is delayed and wake-state instability is common.

Sleep and DNA Methylation, Diabetes and Cancer Risk

According to various studies, biological clock genes play an important role in sleep cycle monitoring and regulation. It follows that, mutation in biological clock genes can lead to a cascade of disruptive neurobehavioral consequences. Lack of enough sleep is associated with epigenetic changes which includes genes methylation, DNA damage in neural cell. Additionally, epigenetic changes lead to increased likelihood of suffering from cancer and diabetes.

According to statistics from the National Sleep Foundation, a disrupted biological clock in night shift workers significantly increased the risk of cancer. Another study was conducted and published in the European Journal of cancer and according to it; women who worked irregular work hours were 30% more likely to get breast cancer.

In another study published by the Journal of American Medical Association, there is a relationship between sleep deprivation and increased chances of developing diabetes type 2. Reduced amounts of sleep are directly related to glucose metabolism disruption and increased insulin resistance. This leads to increased chances of developing diabetes and obesity

Sleep and a Healthy Lifestyle

The benefits of proper sleep are vast. You should never compromise on sleep. It is advisable to avoid caffeine and electronic gadgets before going to sleep. If you get enough sleep, have a daily exercise routine, you can be assured that you will lead a healthy lifestyle.