It would seem, what difference does it make whether to sleep with or without light - if the sleep is sound, then what will interfere with it? But scientists and doctors say that sleeping in the light can significantly harm your health. Let's figure out what the consequences of sleeping with the lamp on are, and how to ensure healthy sleep.
Are you used to falling asleep watching TV? Is your night light on or is your digital clock always on? Do curtains let in light from street lights and signs? It turns out that this is a cause for serious concern. So, somnologist (sleep specialist) Dr. Kenji Obayashi from medical university Nara says that as a result of a series of experiments, it turned out that sleeping in the light can be fraught with insomnia, disturbance metabolic processes in the body, the appearance of excess weight, cardiovascular diseases, the appearance mental disorders, depression and even manifestations of suicidal tendencies.
The area of sleep has not yet been fully studied, and much remains unclear, but scientists have found that during sleep in the light, disturbances occur in circadian rhythms that regulate the alternation of periods of wakefulness and sleep and other physiological processes (the so-called “internal clock” of a person).
To understand what caused this, let us turn to the lives of our ancient ancestors. During the day, the sun was the only source of light for humans; at night, only the moon and stars shone. Artificial light Only a fire could provide. Thus, over the centuries, the same circadian rhythms have been formed that “make” us stay awake during the day and sleep at night.
However, with the invention of electricity, age-old habits began to change rapidly. These changes became especially strong with the advent of televisions and computers. Today they are found in almost every home, and in most cases the process of falling asleep is accompanied by the flickering of the TV. Artificial lighting is brighter than the light of the moon and stars, so a “program malfunction” occurs in the body, and a number of biochemical reactions are triggered, which subsequently negatively affect our health.
One of these reactions is an imbalance in the hormones cortisol and melatonin.
The hormone melatonin is a regulator of our circadian rhythms. The production of this hormone directly depends on the level of light. About 70 percent of melatonin secretion occurs at night. It helps reduce blood pressure, glucose levels, body temperature, providing our body with deep healthy sleep.
It has been proven that excess light inhibits the synthesis and secretion of melatonin, and a decrease in illumination, on the contrary, promotes its active production.
Artificial lighting disrupts the balance of another hormone - cortisol, the levels of which normally decrease at night and increase during the day. Light at night disrupts these processes, and it becomes much more difficult for a person to fall asleep. Moreover, due to an excess of cortisol - the anxiety hormone - not only sleep is disrupted, but also appetite, which will subsequently contribute to the formation of extra pounds.
It is worth noting that hormonal levels are affected not only by the level of light during sleep, but also by the amount of light that affected our body before. Please note that blue light particularly inhibits melatonin production.
During sleep, not only bright light is dangerous to human health. Even dim lighting has a negative impact on your mental state.
Thus, studies conducted on hamsters showed a relationship between light at night and the development of depression. For several nights in a row, the hamsters were illuminated with a dim color, after which the animals lost interest in their favorite treat - sweet water- V daytime. After the hamsters began to sleep in the dark again, their previous cravings returned, and they drank sweet water with pleasure.
The human immune system can also be affected by improper lighting while sleeping. The hormone melatonin is associated with immunological parameters, which significantly worsen with a decrease in its production.
Thus, the luminous display of any electrical appliance at night disrupts sleep and the normal functioning of the body. It is necessary to take care of thick curtains that do not let in the light of lanterns and signs from the street, and also remove all luminous devices from your bedroom while you sleep.
It is believed that excessive lighting may provoke the development of cancer. Violations hormonal levels it simply cannot pass without leaving a trace on the body. One of the most serious health consequences is increased risk cancer diseases.
This has been confirmed scientific research lasting 10 years. During the experiment, one group of women slept in the light, and the other in the dark. As a result, the risk of breast cancer in the first group was 22% higher than in the second. Scientists believe that the reason for this relationship is again melatonin. Earlier experiments demonstrated the ability of melatonin to block the growth of malignant melanoma tumor cells.
Melatonin also helps in the fight against aging of the body. It has a protective effect on brain cells, blocking the action free radicals and preventing degenerative changes. This hormone is even used by people over forty years of age to prevent Parkinson's disease, due to its pronounced antioxidant effects and ability to provide protection inside human brain cells.
IN modern world The problem of obesity has become very common and one of the many reasons for this phenomenon can be considered the lack of melatonin factor. Sleeping in the light at night is disrupted natural rhythms person, hormonal balance And metabolic processes. As a result of such violations appears overweight.
Scientists have experimentally proven the connection between sleep and weight. The study was conducted on mice. It turned out that rodents that slept in the light gained weight much faster than mice that slept in the dark. At the same time, the amount of food, water and physical activity it was the same in all rodents.
Since childhood, you have probably heard that sleeping in the light is harmful. But little ones are often afraid of the dark, and adults make concessions, trying not to provoke evening scandals, and leave the night light on. True, caring parents always turn it off when the child falls asleep. But the habit cannot be turned off so easily. So it turns out that, having already become adults, some leave the dim light burning all night. Scientists tried to find out what this habit entails and why it is necessary to sleep in the dark.
Since man is not a nocturnal mammal, nature has provided that he should sleep in the dark, and in the light of day he should be awake and active image life. For this purpose, our bodies have built-in biological clock, which measure circadian rhythms. Moreover, they work properly even in complete darkness, which has been confirmed by multiple experiments.
A person placed in a completely dark room still goes to bed at about the same time as before when there was external lighting naturally changed. If the light is on constantly, it is more difficult for him to fall asleep, but he still wants to sleep at regular intervals.
Scientists call such alternations circadian rhythms. With a sharp change in time zones, internal settings are disrupted, and for a certain period a person feels severe discomfort.
Having searched for the regulator of this process, scientists discovered a small gland located in the back of the head - the pineal gland. By producing certain hormones and sending them into the blood, the pineal gland stimulates increased activity or drowsiness of the person. During the day, it increases the concentration of serotonin in the blood, and when darkness falls, it begins to actively produce melatonin, called the sleep hormone.
When the concentration of melatonin in the blood reaches a certain level, and this usually happens around 22-23 hours, a person shows signs of drowsiness: yawning, rubbing his eyes, becoming lethargic.
If you go to bed from 22 to 24 hours, then the process of falling asleep proceeds easily and quickly, and then the person sleeps peacefully throughout the night. By 4-5 o'clock in the morning, the production of melatonin is completed, serotonin again enters the blood, preparing us for an early and vigorous awakening.
Having become interested in what the hormone melatonin is and what its consequences are reduced concentration, scientists conducted a number of studies, the results of which turned out to be extremely interesting.
It turned out that melatonin not only promotes falling asleep quickly, but also affects other vital processes occurring in the body.
A lack of melatonin can provoke conditions close to depression. This was shown by experiments conducted on animals that were constantly illuminated at night.
The test hamsters became lethargic, they lost their appetite, and they even stopped being interested in their favorite treats. You will say that the person is not a hamster, but people who regularly sleep in the light complain of very similar symptoms.
The second important function of melatonin is to neutralize free radicals that integrate into healthy cells and provoke their premature destruction. Produced by a gland located in the skull, melatonin primarily protects against brain cell destruction, preserving our memory and clarity of mind.
Now it becomes clear why children who slept in the light all the time showed worse academic results.
Another experiment showed that a test animal that sleeps with a constantly burning light bulb (even in dim lighting!) quickly gains excess weight on the same diet that previously did not give weight gain.
A lack of melatonin leads to a slowdown in metabolic processes. And if you consider that chronic lack of sleep is constantly accompanied by mild apathy and reluctance to move a lot, in humans the process goes even faster.
Sleeping with light is harmful! It leads to obesity, development psychosomatic diseases and insomnia. Moreover, the level of lighting practically does not matter. To produce enough melatonin, you need to sleep in complete darkness. Even street lighting penetrating through the curtains or the glow from an electronic clock is enough to significantly reduce its production, and therefore worsen the quality of sleep.
By the way, along the way, scientists discovered another interesting connection. Depressive state, including those caused poor quality sleep due to the presence of lighting in the room is directly related to a sharp decrease immune defense body. It is no wonder that those who sleep in the light are more likely to suffer from colds and viral diseases.
Why you need to sleep in the dark became clear during experiments that discovered the important role of melatonin in human body. But is it possible to somehow stimulate its production? What can be done to ensure that melatonin concentrations do not decrease to a dangerous threshold?
And most importantly, remember that healthy image life is the key to a fulfilling sleep soundly. The body, not exhausted by artificial stimulants and not poisoned by toxins and poisons, usually does not have problems with sleep.
Modern bedrooms are filled with light - the flickering of a monitor and electronic clock, street lighting. The problem is that constant exposure to light leads to health problems.
To understand why light at night has such a detrimental effect on health, we can look back at history. Bye artificial sources lighting did not fill a person’s life, he had only two “lamp”: during the day - the sun, at night - the stars and the moon, and, perhaps, light from the fire.
This formed human circadian rhythms, which, despite changes in lighting, still regulate the state of sleep and wakefulness. Today is night artificial lighting breaks age-old human habits. It is less bright than sunlight, but brighter than the light from the moon and stars, and this triggers a cascade of biochemical reactions, including the production of hormones such as cortisol and melatonin.
Melatonin production is key to understanding why artificial light is so bad for us. This hormone is produced in pineal gland only under conditions of absolute darkness and is responsible for the sleep-wake cycle. Melatonin lowers blood pressure, body temperature and blood glucose levels, that is, it does everything to provide the body with restful, deep sleep.
There is a part of the human brain that is responsible for the biological clock - the suprachiasmatic nucleus in the hypothalamus. This is a group of cells that respond to darkness and light, and gives signals to the brain about when it is time to fall asleep and wake up.
In addition, the suprachiasmatic nucleus is responsible for changes in body temperature and the production of cortisol. At night, the amount of cortisol decreases, allowing us to sleep, and during the day it increases, regulating energy levels.
All these processes are natural, but artificial lighting at night disrupts them. The body reacts to light and increases cortisol levels at night, making it more difficult for a person to fall asleep. Besides, high level The stress hormone reduces the body's resistance to insulin and inflammation. As a result of the fact that cortisol is not produced at the right time, appetite and sleep are disrupted.
However, hormone levels are regulated not only by the amount of light at the moment, but also by how much light you received before.
Studies have shown that if a person spends time in room lighting before bed, less melatonin is produced for 90 minutes, compared to dim light. If you sleep in room lighting, melatonin levels decrease by 50%.
From this perspective, any light in your bedroom becomes real problem, and tablets, smartphones and energy-efficient lamps only make things worse. The point is that Blue light from LEDs is particularly potent in suppressing melatonin production.
Unfortunately, disruption of hormone production provokes not only bad dream, but also more serious consequences, for example, cancer. A 10-year study showed that sleeping in light increases the risk of cancer.
Participants in the experiment who slept in the light were 22% more likely to develop breast cancer than women who slept in complete darkness. Researchers believe this depends on melatonin levels. Even earlier, in vitro experiments proved that melatonin blocks the growth of melanoma cells.
In another study, rats with breast cancer xenografts received blood perfusion from women who slept in bright light and from participants who slept in complete darkness. Those rats that received blood from the former showed no improvement, while in the latter the tumor decreased.
Based on the data from these studies, we can say that sleeping in the dark prevents cancer and we can only sympathize with people working the night shift.
Unfortunately, the light in the bedroom at night does not have to be bright to cause damage to health - even dim lighting will suffice. Studies conducted on hamsters have shown that dim lights at night cause depression.
Hamsters exposed to dim lights at night showed less interest in the sweet water they love so much. However, when the lighting was removed, the hamsters returned to previous state. In addition, constant dim light in the bedroom is bad for the immune system, since melatonin levels decrease, and along with it, immunological indicators deteriorate.
That is, if you have an illuminated electronic clock or other luminous devices in your bedroom that work all night, there is a serious reason to wonder whether you really need them. And this is not to mention the constant light from street lighting that comes through your window when there are no thick curtains.
Melatonin helps fight aging. It protects brain cells from free radicals and prevents degenerative changes. The hormone functions as an antioxidant, which provides protection inside brain cells, and can even be used by people over 40 years of age to prevent Parkinson's disease.
The next problem caused by melatonin deficiency is obesity. Light at night has been proven to promote weight gain by disrupting the body's natural rhythms. Experiments conducted on mice showed that rodents exposed to night light gained weight much faster than those sleeping in the dark, even though the amount of food and activity was the same.
To summarize all of the above, we can derive several rules:
The dark time of day is created for sleep, this is the natural cycle for humans. At night, the activity of organs decreases, cell reactions slow down, and the sleep hormone is released. Disrupting this process even with weak light means exposing your body to unnecessary danger.
The habit of sleeping with the lights off has a beneficial effect on a person’s health, gives strength, and allows you to wake up cheerful and active the next day. In addition, the absence of light during sleep helps prevent depression and drowsiness, maintaining health, beauty and youth longer. Just as negatively as light, a television or a glowing computer screen on a person during sleep has an effect on a person. It's all about the work of the hormone melatonin, which is produced only in the dark. It helps a person fall asleep faster, sleep soundly throughout the night and wake up rested and well-rested. In the light, the hormone melatonin is completely or partially destroyed, the human body does not receive it in full degree, which provokes sleep problems.
It has been observed that the more time a person spends with light during sleep, the higher his risk of developing depression and problems falling asleep. Such people toss and turn in bed, they develop negative thoughts, which, coupled with light, prevent them from falling asleep, restless and intermittent sleep appears, and even insomnia may develop. Naturally, after such a difficult night in the morning they feel exhausted, do not perceive what is happening well, are more susceptible to colds and viral diseases, mental disorders, suffer from nervous tension. All these symptoms can appear gradually and very imperceptibly for a person, but, accumulating, they provoke a whole complex of diseases and disorders, the cause of which people may not even notice.
Melatonin is not only a sleep hormone, it also promotes rejuvenation of the entire body. It is thanks to its lack that after 30-40 years people age so rapidly. You can correct this situation if you take melatonin before bed - this will improve your overall tone, allow you to fall asleep faster and easier, and preserve your youth for a long time. Taking a drug based on this hormone will allow adults to fall asleep peacefully even with the light on. However, there is no need to consider this remedy as a sleeping pill. If you have insomnia that neither calm walks before bed, nor relaxing procedures or soothing drinks can help you get rid of, it is best to consult a doctor.
Why it is so necessary and important to sleep in the dark. What hormone problems can this lead to? How to prevent this and how to ensure that your sleep becomes sound and complete.
Everyone knows how important sleep is for us.
During sleep, our body not only rests, it repairs itself. Everyone knows that it is advisable to go to bed and get up at the same time. Our body quickly gets used to the routine and adapts. Everyone knows that you need to sleep at least 6-7 hours.
Does everyone adhere to these simple, long-known rules?
In the age of technology, we fall asleep in front of the TV, some even manage to do this in front of a computer, tablet, or phone.
Many parents leave a night light on in their children’s room all night, for many reasons, easily explained and for obvious reasons(children are often afraid of the dark, they will suddenly wake up and want to go to the toilet, and so on).
But many people don’t even suspect that they need to sleep in complete darkness.
It turns out that our body has its own biological clock built into it, which controls many important processes in our body.
One of these processes is the production of the hormone Melatonin, which (unfortunately for many people) is produced only in complete darkness.
And why this is so important and you need to know, I will tell you in this post.
It is a hormone that is secreted pineal gland our brain. This gland, by the way, is also called the third eye.
The urge to produce Melatonin is the absence of light.
This dark-loving hormone plays a large role in physical and mental health, controls our mood and, in addition, is a strong antioxidant!
Melatonin deficiency can cause numerous and very serious problems with health.
This and weak immunity, increased risk of formation malignant tumors(study of the relationship between low Melatonin levels and breast cancer), hypertension, cardiovascular diseases, hormonal imbalance, obesity.
Scientists consider the lack of this hormone as one of the possible risks for the development Multiple Sclerosis and depression.
As I already mentioned, we humans, like all creatures of the animal world, have our own daily or circadian rhythm, which tells us that we should go to sleep when it gets dark and wake up when it gets light.
Which is exactly what our ancestors followed. I remember my grandmother, who went to bed probably at 9 pm and woke up with the sunrise - around 6 am.
The ancient Indian science of Ayurveda says the same thing: go to bed no later than 10 pm and get up at 5-6 am. This is explained by the energy of the sun and our connection with this energy.
But there is more scientific explanation, which fully supports Ayurveda.
Inside our hypothalamus live a group of special cells called cells. Suprachiasmatic Nucleus, which control our biological clock, again depending on the lighting.
Light reaches these cells through our optic nerve.
When it's time to wake up, for example, light stimulates these cells. At the same time, lighting provokes the beginning of a whole process of “waking up” of our entire body, which goes unnoticed for us. Our body temperature rises, hormone synthesis increases Cortisol.
When these special cells do not receive enough light, they begin the reverse process - the production of a hormone Melatonin, which can be said to help us sleep.
That is, it turns out that if at night you sleep with the TV on (and yes, even this seemingly dim lighting can interrupt the synthesis of Melatonin) or the night light on, then you are on a serious road hormonal imbalance, which threatens problems not only with the quality of sleep, but also with general health.
In addition to this, artificial lighting, when natural light is no longer available, increases the synthesis of the hormone Cortisol, which prevents you from falling asleep, provokes hunger and triggers a number of chronic inflammatory reactions.
« Sleeping in the dark « This will sound very cliché, but this is the simple, uncomplicated truth.
