In this series of articles, renowned experts answer questions that are usually awkward to ask because it seems like everyone already knows about them, and asking them will make you look stupid.This time we talked to sleep doctor Mikhail Poluyektov about how much sleep an adult should get, whether owls and larks exist, and whether it is possible to control your dreams.
1. How much sleep does an adult need? What happens if you don’t get enough sleep? And what if you sleep too much?
The first question is actually quite easy to answer, since official international recommendations for sleep duration for people of different ages were in 2015. At that time, world experts in the field of sleep science and medicine got together and came to an agreement that adults need to sleep from 7 to 9 hours in order to achieve the best recovery of the body and minimize the risk of health problems associated with lack of sleep.
There is not much information about the impact of lack of sleep on various aspects of human health. The negative impact of lack of sleep on the cardiovascular system has been well proven. There are many such , and they all agree on one thing: lack of sleep increases average blood pressure and the risk of developing arterial hypertension by 1.4 times.
Additionally, it has been that people who sleep less than the recommended amount of time are more likely to develop diabetes .
And the third proven : even in a healthy person, a reduction in sleep time by 1 or 2 hours leads to a decrease in immunity by about 1.5 times.
But the situation with excessive sleep is not yet entirely clear. The data from the same studies show that the risk of developing, for example, cerebrovascular disorders and diabetes also for some reason increases in people who sleep too much. But scientists still believe that this is simply incorrect statistics, since people who initially have some kind of disease have a greater need for sleep and sleep longer.
2. Do you really need to go to bed before 11:00 pm?
It is believed that the main indicator that it is time to sleep is the beginning of the production of the hormone melatonin. This is a substance that is produced precisely at the signal of our internal clock that night has come.
However, this does not mean that if it gets dark at 4:00 PM in winter, it is time for us to sleep. In addition to the information that comes to us through the eyes, there is also, in fact, the work of our internal clock. The information that comes to us through vision complements and allows us to slightly adjust the work of our systems. Therefore, even in winter, the body will understand that at four in the evening it is not yet night, although it is dark, and melatonin will still begin to be produced by about nine o’clock.
Our natural sleep time starts around 9-10pm and ends around 7am, when melatonin stops being produced.
Ideally, we should provide ourselves with sleep in the range, say, from 10 pm to 7 am. As we understand, this interval includes not seven hours, but nine, so we can vary the time of falling asleep and waking up a little.
If we regularly fail to follow this regime, go to bed late at night and get up when it is already light, the production of melatonin will be disrupted. And this hormone is very important for the body: it helps to fall asleep, resist stress, and is an antioxidant. When going to bed late, the work of hormones is disrupted, a person can become lethargic and irritable.
3. Do adults need daytime sleep?
An adult can do without daytime sleep if he sleeps enough at night. If he does not get enough sleep at night, then he can really make up for this lack of sleep during the day.
For people who get enough sleep, a short nap during the day can improve mental performance and productivity. But this is true for short naps of 10, 20, and 30 minutes.
If a person sleeps during the day for more than 30 minutes, he dives too deeply into sleep and then, upon waking up from this sleep, he, on the contrary, is less productive. Therefore, it is better not to overdo it with daytime sleep if the night sleep is sufficient.
4. Why do some people fall asleep very quickly, while others cannot fall asleep for a long time, although they also feel tired?
A healthy person should fall asleep within 15 minutes. If it takes him longer to fall asleep and if this problem occurs more than twice a week, then he has a disease called ” insomnia ” and he should see a doctor.
In order to fall asleep better, you need to follow several rules of sleep hygiene:
- It is necessary to establish a clear time for going to bed and getting up so that the body can internally prepare for evening relaxation and morning activity.
- It is necessary to provide a period of switching from daytime wakefulness to evening relaxation: stop active stimulating activity, do not jump, do not play on the computer, do not actively communicate on social networks , do not use stimulants. That is, give your body the opportunity to switch to a calmer mode, arrange an hour of silence for yourself.
- Remove additional stimulation from the place where we sleep: sources of light, noise.
These are the rules that people who have problems with sleep should start with.
5. Why are some people owls and others larks?
There are very few true owls and larks – only 10% each. And the remaining 80% of people are pigeons – those who do not care when to be active: in the morning or evening hours.
Genetics are responsible for about 50% of this behavior. But the other 50% is due to so-called social factors. That is, you may consider yourself a night owl, but circumstances, such as your work hours, are such that you have to get up early and start your activity. Most people adjust quite easily under such circumstances.
Of course, it is possible that you have many genes that dictate your “night owl” nature, and it is extremely difficult for you to adapt to early rising. Then it is better to try to arrange your life so that the main work activity occurs in the evening.
But again, this is only true for 20% of people. Most people don’t really care when they wake up .
6. Why do we sometimes sleep long enough but still wake up tired?
Usually the first reason for fatigue is not sleep itself, but the general state of the nervous system. In modern society, people live with constant emotional and informational stress. They have to keep too much in their heads, react to too much. This is what prevents the nervous system from recovering.
Therefore, if you get enough sleep but don’t feel rested in the morning, you should consider whether you need to reduce the load on your nervous system.
7. Do our dreams mean anything or not? Are there prophetic dreams?
There is still no consensus among sleep researchers about whether our dreams mean anything.
Physiologists, for example, believe that dreams are a reflection of the processing of information that our brain has been doing during the day. We saw something, talked to someone, and we can dream about it because the brain continues to process this information during sleep. Dreams are echoes of this work.
Sometimes dreams become unusual, they include childhood memories, people we haven’t seen for a long time. Dreams become complex. Scientists explain this by the fact that memories are more easily activated in sleep, they can surface mixed up, and in order to somehow explain their appearance, the brain can come up with a story that we see in a dream.
That is, from the point of view of classical medicine, dreams are just noise that occurs in the process of processing information and does not mean anything.
On the other hand, there is a psychological theory that says that dreams carry very important information and through them the subconscious tries to reach a person through images. Psychologists and psychotherapists are engaged in solving this symbolism.
Prophetic dreams do happen, and from a scientific point of view, there is nothing special about them. Our brain is also a machine for looking into the future, for forecasting. During wakefulness, the brain creates certain familiar images and reacts to their changes. For example, we see a familiar environment and do not pay attention to it until something changes (for example, a door opens and someone enters the room) and this change does not coincide with the “image of the future” that our brain has already built. If this happens, we will immediately begin to react: we will turn our head, take a closer look, and so on.
The same constant prediction of the future occurs during sleep, but the brain takes information to form these predictions only from memories. Therefore, in most cases, the predictions that the brain makes during sleep do not come true. But sometimes they can come true randomly, which impresses us very much.
8. Is it possible to influence your dreams?
It is possible to influence dreams; the practice of lucid dreaming has been known for quite a long time.
Lucid dreaming is a state of consciousness in which a person understands that he or she is dreaming and can control it. It can be learned, but it is quite tedious, like, for example, learning to meditate.
If a person masters this technique, he will actually be able to realize that he is in a dream and change its content by an effort of will.
Another question is why is it necessary? Dream control has no practical meaning. Lucid dreams have been used to treat neuroses and other similar diseases. But the efforts a person spends to learn how to control his sleep do not correspond to the benefit he receives. For now, it is much easier to treat with medications.
So now the practice of lucid dreaming exists, but no one knows why it might be useful.
9. What does our brain do while we sleep?
All the same things he does while we are awake.
The brain is a computer that has to process data. During the day, it organizes new information coming from the senses and old information that we already had, such as memories .
During sleep, new information does not arrive, but the brain continues to organize what it already has. One of the important functions of sleep is to remember the information received. This information can also be creatively processed during sleep and lead to unexpected conclusions.
Also, during sleep, the processes of cleansing nerve cells are accelerated. For example, the removal of harmful metabolic products, such as beta-amyloid protein,
10. Are gadget screens really harmful before bed? And is short daylight harmful?
Yes, it has been proven that spending long periods of time in front of screens in the evening can lead to a decrease in the production of melatonin, the hormone that signals the onset of the “inner night,” that we can relax and switch to night mode. One showed that two hours of screen time in the evening led to a 23% decrease in melatonin production, which is quite significant.
But on the other hand, melatonin is one of the additional factors that helps you fall asleep, but it does not directly affect sleep. Therefore, there is no guarantee that such a decrease in melatonin production will actually lead to sleep disturbance. After all, the state of sleep depends to a much greater extent on psychological comfort, on the degree of excitation of the nervous system. Therefore, to fall asleep better, first of all, you need to ensure psychological comfort before going to bed . Everything else would also be nice to provide, but this is not a mandatory condition.
As for the short daylight hours in the autumn-winter season, it has indeed that sleep characteristics change at this time. In terms of quantity, sleep becomes a little more, and in terms of quality, a little worse. But this is usually a non-critical change and does not matter for a specific person, for his real life. This is simply scientific data.
