Development and Function
Healthy and sufficient sleep is essential to our well-being, important for recovery and performance. Sadly, restful sleep does not always occur naturally. Many people around the world suffer from sleep disorders that not only massively inhibit quality of life, but can also create health problems.
Sleep is a central and vital basic need during which important processes are completed. While we are sleeping our body regenerates. This also stabilizes our immune system, repairs cells and processes the impressions of the day. Additionally, new information is processed into long-term memories while we are sleeping.
The science behind chronobiology has long recognized that melatonin, a neural hormone which is distributed at night and plays a significant role in the regulation of our circadian rhythm, is necessary in order to find good and healthy sleep. Melatonin is produced in the pineal gland of the brain and controls our inner clock, stimulates the activity of numerous cell groups and regulates our sleep. Additionally, this hormone possesses an antioxidant effect. If melatonin production is disturbed, or if not enough of the hormone is being produced or distributed at the correct time, then our sleep is impaired, which can lead to a number of different illnesses.
At night our body undergoes a number of sleep phases:
- Falling Asleep Phase (transitional period between being awake and sleeping, the body comes to rest, pulse becomes slower, breathing becomes regular)
- Light Sleep (usually just a few minutes, relaxation of muscles)
- Deep Sleep (here actual regeneration takes place, waking up is difficult)
- REM Sleep Phase (rapid eye movement, brain is unusually active, dream phase)
These sleep phases are passed through multiple times in one night. After REM sleep, the body falls back into light sleep and the sleep stages begin again. Each cycle lasts approximately 90 minutes.
Sleep Disorders and Their Frequency
While children and babies require large amounts of sleep (infants require 16 or more hours), the average length of sleep for adults is between 6 and 8 hours each night. Sleep behavior varies from person to person and is dependent on chronotype (owl = night person, lark = morning person). A sleep disorder is present if a person receives less than 6-7 hours of sleep every night for a time period of at least 6 months.
20 to 30 percent of humans suffer from sleep disturbances, with men and women suffering equally. In those over the age of 65, the number grows to 70 to 80 percent. Only a third of these (30-35 percent) visit a doctor because of this. Around 70 percent of those suffering from sleep problems are prescribed a sleep aid such as benzodiazepine, while 30 percent are self-medicated (f.e. through the help of antihistamines).
“Too little sleep makes one dumb, fat and sick.” A bold statement which sadly is grounded in truth. Insufficient sleep causes a number of mental and physical illnesses.
Effect on Memory
What we learn during the day is solidified while we sleep (sleep associated memory consolidation). Those who suffer permanently from lack of sleep will have to count on decreased memory capability. Numerous studies have found this to be true. Sleep disorders contribute to the limitation of memory formation, leading to forgetfulness, difficulty concentrating and overall performance reduction.
Effect on Weight
Those who sleep too little also show an increased risk for obesity. Lack of sleep means that we are awake longer, which can lead to poor habits such as watching TV and playing on the computer that require less movement and cause us to run to the refrigerator late at night for an unhealthy snack. Late at night we are especially prone to enjoy calorie rich foods. Studies have shown that people who sleep less eat more than those who sleep enough. Lack of sleep can lead to increased appetite, which finally leads to weight increase. Hormone changes that are triggered through missing sleep are responsible for this. Even if we do not eat too much, but eat more at night, then the ingested calories are more likely to be saved as fat.
Effect on Mental Health
It is not uncommon for mental illnesses to be fostered through permanent lack of sleep. In not-so-serious cases this is expressed through constant tiredness, irritability, lack of motivation and mood swings. In the worst cases it can result in hallucinations or depression. These disturbances can appear when the brain is overburdened due to a sleep deficit, especially if a predisposition of mental illness is present.
Effect on Physical Health
Too little sleep has negative consequences for our immune system. This encourages the development of illnesses that can take the form of harmless colds or flu symptoms. However, long-term sleep disturbances can lead to serious health problems. Chronic sleep disturbances in an average of three out of seven nights can increase the chances for gastrointestinal ailments, heart attack stroke, diabetes, vascular diseases and even cancer.
A study conducted by the European Heart Journal found that the risk for heart disease increases by 48 percent if we consistently sleep less than six hours. Other studies have proven that sleep deprivation can lead to high blood pressure, clogging of the arteries and heart failure.
One study from Japan also showed a connection between sleep disorders and diabetes. It was able to determine that a heightened long-term blood sugar value (HbA1c-Wert) showed a clear correlation with problems sleeping through the night and waking up too soon in the morning. It is suspected that poor sleep causes the release of stress hormones (i.e. cortisol) which favor the development of diabetes.
Last but not least, insufficient sleep can also trigger cancer. People who can ascribe their sleep disorders to shift work show an especially high risk. In 2007 the International Cancer Research Center of the WHO classified nightly shift work as “probably carcinogenic.” A heightened risk for cancer was especially found in hospital personal and flight attendants, since the permanent displacement of the biological sleep-wake order and the use of artificial light encourages the development of tumors.
- Long wake time phases, falling asleep is difficult
- Waking multiple times while sleeping
- Sleep is uneasy and not restful
- Slow start in the morning
- Tendency to fall asleep during the day
- The body is overstimulated and tense
Sleep can be influenced negatively through external (exogenous) or internal (endogenous) factors.
Exogenous Sleep Disorders
Jetlag is the case when multiple time zones are traversed in a short amount of time, so that the inner clock is no longer in agreement with the actual time. This causes hormones to become confused that are normally subject to a daily rhythm. Jetlag becomes worse the more time zones are crossed, as the adjustment of inner rhythms can only occur slowly. The direction of flight also has an impact on the development of jetlag. The body can handle flights going west better than those going east. The reason for this is that our inner clock does not adhere to a strict 24 hour schedule, but rather somewhat lengthier clock phases. Since flights towards the west lengthen the day, they are of greater advantage to our inner clock.
Shift work is comparable to a trip through multiple time zones, which is why it is sometimes called social jetlag. Permanently changing work hours and night work confuse the body’s natural circadian rhythms. Shift workers have to constantly adjust their inner clock due to changing work hours. These workers suffer from permanent lack of sleep. On average, their time of sleep is two to four hours shorter than that of people who hold normal working hours, since quality of sleep during the day is poorer than that at night due to disturbances.
- Once on your plane, change your clock to that of the destination country in order to counteract jetlag
- Follow the daily rhythm once in the destination
- Spend a lot of time outside during the day
- When traveling east, take a few days to go to bed an hour or two earlier. When traveling west, go to sleep a few hours later than usual
- Supplementation through melatonin
- Try to rotate forwards
- Very bright light at the workplace (over 300 lux in order to counteract nightly low points)
- Short naps (power napping) during a night shift increase concentration. These little naps should last between 5 and 10 minutes
- After work, wear sunglasses so the body does not program itself to being day when it is already light outside
- Eat light meals, otherwise the body becomes tired and sluggish
- A lot of movement
- Adhere to set meals, breaks and sleep times
- Supplementation through melatonin
Pharmacologically Induced Sleep Disorders
Certain medications such as beta blockers, stimulants such as alcohol and caffeine, as well as nicotine and overeating at night can trigger sleep disturbances. Alcohol can help you fall asleep, but it can cause you to wake up early in the second half of the night and have problems falling asleep again. The portion of REM sleep is impaired and amphetamines eliminate the need for sleep.
The human psyche is very complex. Problematic emotional states such as stress, anger and fear can be just as responsible for sleep disturbances as serious mental illnesses such as depression and burnout. This is why it is important to figure out the cause of these problems in order to find suitable countermeasures.
Endogenous Sleep Disorders
In order to produce melatonin our body requires sufficient serotonin. Our modern way of life that is marked by daily stress, unhealthy nutrition, sensory overload and lack of exercise can be responsible for lack of serotonin along with physical illnesses. However, age also plays a significant role. The older we get, the less melatonin is produced in the pineal gland as it becomes more and more calcified. Another cause is light, specifically light during the night phase impairing endogenous melatonin production. If, for whatever reason, the body is not producing enough melatonin, then sleep disorders will manifest themselves. In this case, a supplementation of the sleep-encouraging hormone is sensible.
Delayed Sleep On-Set Syndrome
A delayed sleep on-set syndrome is characterized by problems falling asleep. This is generally present among youth and young adults that fall under the chronotype “night owl.” These people make the night into the day, stay awake into the wee hours of the morning, and then sleep into the afternoon. Those affected report chronic sleeplessness. The delayed sleep on-set syndrome of night owls is best treated in the morning with the help of light therapy. It is advisable to perform light therapy early in the morning in order to move the sleep-wake rhythm forward. Similar effects can be reached by taking melatonin in the early evening.
Sleep-Weak-Disturbances in Blind People (Non-24 Syndrome)
“Non-24 syndrome,“ or simply “non-24“ or “free running syndrome“ was described for the first time in 1948 by Dr. Remler from Germany. He described in his scientific publication that some blind people had inverted their circadian rhythms for temperature, heart frequency, blood pressure and excretion.
Non-24 is a serious, severe and chronic disturbance of the day-night rhythm that is especially common among blind people. People with non-24 syndrome are not able to set or synchronize their inner clocks according to the 24 hour rhythm of a day. These people live in their own rhythm that lasts between 24 and 25 hours. This leads to falling asleep or getting up 30 minutes later every day. All other rhythms of the body such as body temperature, hormone distribution, or the high point in activity also shift accordingly.
The goal of a chronobiologically correct therapy is to synchronize the inner clock of a person with the 24-hour rhythm of a day. This can include a morning light therapy as well as the use of substances that suppress tiredness during the day. Nightly administration of melatonin or similar substances serves not only to encourage sleep at night, but also as a timer to set the inner clock.
Obstructive Sleep Apnea Syndrome
This syndrome has become relatively well known since it was first defined in 1972 by Christian Guilleminault. The term “apnea” comes from the Greek “apnoe,” meaning non-breathing. This syndrome is characterized by short periods of respiratory arrest during the entire night that repeat themselves. The upper airways of affected people are contracted during sleep, which often leads to snoring. Breathing is not possible, or only possible with great effort. Characteristics of an obstructive sleep apnea syndrome are at least five apneas or hypopneas every hour that last at least 10 seconds each. Many subsequent illnesses are linked to this syndrome such as cardio-vascular illnesses, high blood pressure, anxiety disorders, diabetes and depression. Those affected are primarily men between the ages of 30 and 60, but women are also affected. Obstructive sleep apnea syndrome is often discovered fairly late and occurs often. Possible treatment options include surgical intervention, intraoral protrusion splints or CPAP therapy.
Restless Leg Syndrome
This is a very common neurological disorder. This syndrome is characterized by a disturbance in the central nervous system. At the forefront of this problem are faulty feelings of pain in the legs, which is present in most affected people at bedtime. The pain is experienced differently from person to person (i.e. tingling, stabbing, pulling or tearing). Only movement brings relief from the pain. Women are affected twice as often as men and the syndrome is especially common among pregnant women in the last few weeks before birth. The cause is not yet fully explainable, but a genetic predisposition is assumed. Therapy utilizes dopamine-like substances, i.e. L-Dopa, or so-called dopamine agonists. If a disturbance in melatonin release is also partly to blame, that is still being intensively researched.
Hypersomnia – Narcolepsy
A special form of sleep disturbance is the need for more than seven hours of sleep. Due to factors that have not yet been completely explained, affected people must have more than seven hours of sleep in order to feel rested and rejuvenated. In the case of narcolepsy, patients are suddenly overcome by an intense need for sleep so strong that they immediately fall asleep. The causes for these sleep disturbances have not been fully researched to this day, but genetic factors and changes in certain messenger substances have been documented. A causal therapy is not yet available.
In order to prevent sleep disorders or control current difficulties, you should try to maintain good sleep hygiene.
This contains the following measures:
- Reduce the amount of mental and physical exertion in the evenings.
- Do not eat a large meal less than two hours prior to bedtime, but choose light food and small portions.
- Make it a habit to keep a strict bedtime and wake time.
- Caffeine, nicotine and alcohol encourage sleep disturbances.
Avoid alcohol completely or reduce it to a minimum and the other stimulants should never be enjoyed past the afternoon.
- Exercise is important for the body, but try to avoid extreme exertion for three hours before bedtime.
- Before going to sleep the use of electronics of all kinds—including TV—should be avoided, as the blue light emitted by them can impair melatonin distribution.
- Make sure that your bedroom is quiet, dark, and has a correct temperature (60-65 degrees Fahrenheit is ideal).
- The bed should only be used for sleeping and sexual activity.
- To calm down you can use herbal teas or warm milk with honey, as these encourage sleep.
- If you have trouble relaxing, certain relaxation techniques can help you find rest.
- Keep a regular sleep rhythm, even on the weekends, in order not to throw your circadian rhythms off sync.
In circadian rhythm disruptions such as jetlag, shift work, or delayed sleep on-set syndrome, enough melatonin is being produced, but at the wrong time. Using melatonin at the correct times makes it possible to help set your natural circadian rhythm according to the night rhythm that you need. This type of therapy is also called chronotherapy, as it does not replace melatonin, but rather regulates its endogenous distribution.
If a slight or severe melatonin deficiency is the cause for sleep disturbances, then melatonin must be replaced, i.e. with the help of hormone replacement therapy. A chronobiologically optimized galenic formula is used which releases melatonin for six hours.
Light therapy is an uncomplicated and effective method in the treatment of sleep disorders without side effects. It uses light intensities from 2,500 to 10,000 lux. As a natural timer, high light intensities influence the hormonal balance of the body and with it, its circadian rhythm. The goal is to move this rhythm forward, or push it back. In the case of going to bed early and getting up early, the circadian rhythm is pushed back. When going to bed late and getting up late, it is moved forward. This method already shows improvement in sleep quality and overall wellbeing within one week. However, this therapy only works for people who still produce sufficient melatonin.
Certain methods that contribute to relaxation can help you sleep more efficiently.
- Biofeedback: This process helps to steer apparently autonomous physical functions. Patients should learn how to use the power of thought in order to find rest when experiencing sleep disturbances. The biofeedback method enables affected people to produce a state of relaxation mentally that they need in order to fall asleep. The training occurs with the use of electromyography that helps to detect and loosen muscles for a relaxed state. This method is suitable for anyone and is easy to learn. Approximately eight to 20 hours are necessary in order to heal sleep disorders.
- Autogenic Training: This is a complex relaxation method that primarily deals with self-suggestion. Using this method, you concentrate on the relaxed state of individual body parts and attempt to influence them with the help of self-suggestion (f.e. my right leg is light as a feather). This evokes physical changes.
- Meditation: This technique focuses on intensive concentration on individual objects (f.e. specific pictures, one point in the room, etc.). The goal is to reach a state of “thinking about nothing,“ which can provide as much relaxation and energy as an hour of sleep in just a short period of time. Numerous scientific studies support the efficacy of this method, since meditation calms bodily functions.
- Progressive muscle relaxation according to Jacobson: This method is the most common relaxation technique currently in use. This process is supposed to allow you to successfully relax strained muscles through tension. Individual muscle groups are tensed in small units for a few seconds and then relaxed. The tension should last between five and 10 seconds, and the relaxation should last between 30 and 45 seconds. The goal is to reach a deeper state of relaxation in all muscles.
There are two approaches to synchronize the endogenous rhythm of blind people with the normal day-night rhythm. On one hand, melatonin can be used as a timer hormone in the evening. Ingestion of melatonin signals the body that it is night time. Currently there are also other substances available similar to melatonin, i.e. tasimelteon (Hetlioz®), which should also be taken in the evenings and uses the melatonin receptors in the brain in order to adjust the inner clock to fit the normal day-night rhythm.
On the other hand, there are also a variety of medications that suppress tiredness during the day. One example of these substances is armodafinil (Nuvigil®). It increases wakefulness in patients that suffer from excessive sleepiness. This drug works by addressing specific neurotransmitter receptors and by stimulating the sympathetic nervous system.
Next to the natural hormone melatonin (which influences the sleep-wake rhythm, helps with problems falling and staying asleep, reduces jetlag and symptoms and increases sleep quality), a number of other plant substances also exist that have a positive effect on sleep and are chronobiologically designed to be optimally combined with all natural and biological substances.
Substances With a Positive Effect on Sleep:
- Lemon balm
- Passion flower
- Mint leaves
Substances With a Negative Effect on Sleep:
- Alcoholic beverages
- Certain medications (i.e. sleep aids such as benzodiazepine and barbiturates, as well as antidepressants and dopamine)
- Fatty or hard to digest meals in the evening