Sleep is an integral part of our life. Even if we try to deprive our body from sleeping, it will protest. But why do we need to sleep?Sleep is necessary for us. People can live without any food quite for a long time, but if we make ourselves awake for more than five days, we can get serious health problems and even die. So, why is it so important to sleep? Scientists from all over the world do not agree about the answer to this question. There are a lot of theories describing the purpose of sleeping, but we still do not know each of them is 100 per cent correct.
Do we sleep to restore our powers?There are scientists who believe that our body sleeps to restore everything it has lost when we were awake. According to this theory, exactly this function of sleep helps us to stay healthy. Scientists studied the reaction of mice on sleep deprivation. They found out that the immune system of mice that were not allowed to sleep for some days reduced significantly. The scientists, who support this idea, assume that when people sleep, their muscles grow, tissues repair, protein is produced and growth hormone is released. Also, people who are adherent to this theory add that when we are awake our neurons in the brain produce a special substance adenosine. The more adenosine our body has, the more tired we feel. When we sleep our body has a chance to clear the body from this substance. It means that our body has to sleep to remove unnecessary substances from it. This hypothesis has been proved by the research conducted in 2013. The scientists found out that our body removes waste toxins from our central nervous system. Moreover, the researchers say that sleep problems may result in failure to “clean” the brain and cause the development of different diseases connected with the brain.
Do we need sleep to digest the information?Many people believe that we need to sleep to allow our brain putting our memory in order and preparing it for the next day. According to this function of our sleep, experts recommend that students have a good sleep before any exam to let the brain digest the information they have studied. The study of 2011 shows that sleep helps our body to form long-term memory. The researchers found out that when we sleep the newly received information distributes to other neuron connections which play a role of long-term storage. The scientists admit that when we sleep our brain process not all the information we get during a day. It selects the “most important” pieces, transforms them and transfers to the long-term memory. This theory that our brain is processing the information when we are sleeping is confirmed by the fact that people show really poor ability to recall information when they are deprived from sleep.
Do we sleep to save energy?Another theory of sleep is called energy conservation theory. It states that we need to sleep to save energy. Although, it is really difficult to believe in this theory today, when we have enough food to replenish the energy demand, the scientists say that we have inherited this necessity of saving energy from animals. The results of a research show that when we sleep our metabolism is significantly lower than when we are awake. In addition, the temperature of our body lowers as well as the caloric demand. These facts support the hypothesis that our body needs to sleep to conserve energy.
Sleep is one of the less studied phenomena. It is a very complicated process. When we sleep, our brain does not stop its activity, but continues functioning according to some special cycles. There are a lot of theories concerning the purpose of sleep. But still scientists cannot find a universal theory that could clarify all the mechanisms of the sleep.
Why Do We Sleep – Healthy Sleep
Why We Sleep – TUCK
Theories of Sleep – VeryWellMind
Sleep Drives Metabolite Clearance from the Adult Brain – Science
NCBI – materials