Sleep theories: Why do we sleep?

It still remains a mystery why we sleep. Various theories suggest that it has something to do with how our brain stores memories and other functions of both our brain and body. All human beings take pleasure in sleeping, especially those who have trouble sleeping. But why do we sleep?

Why We Sleep Anyway

The human body regulates sleep in the same way that it regulates eating, drinking, and breathing. This means that sleep has a similar vital role in our overall health and wellness. Sleep is basically required for our survival.

While we may not often think about why we sleep, most of us recognize at some point that sleep tends to make us feel better. Because after a good night of sleep, we feel more alert, energetic, livelier, happier and just better overall. Nevertheless, considering the fact that sleep makes us feel better, sleeplessness can make us feel worse.

Theories About Why We Sleep

Although scientists haven’t found a definite explanation why our brains need so much sleep, there are a few interesting and perhaps helpful theories that exist:

Information processing theory — A number of research studies have revealed that REM sleep and/or non-REM sleep might be essential for the brain’s ability to process and fuse memories from the preceding day, forming recent neural networks and strengthening existing ones. Related research studies have also shown that sleep helps our brain get rid of unnecessary information, making room for new neural connections.

Damage reversal theory — When you are awake, neurons in the brain are subjected to the wear-and-tear of oxidative stress that is brought about by free radicals. Damage reversal theory considers sleep as a period that allows the brain to cool down. Sleep also promotes homeostasis in the body and brain that helps repair any damage that has taken place during waking hours.

Adaptive inactivity theory — Sleep is an evolutionary adaptation to help us cope with the lack of sunlight that occurs for about a third of the 24-hour day. Curling up and sleeping in a hidden place keeps us out of harm’s way during the dark.

Energy Conservation Theory – This theory suggests that the primary function of sleep is to decrease a person’s energy demand and expenditure during part of the day or night. The point is to reduce our need for calories so we don’t have to spend 24 hours a day looking for food.

Restorative Theory – Sleep is known to restore what is lost in the body while we are awake. Sleep permits the body to repair and rejuvenate itself. Many of the major restorative functions in the human body such as muscle growth, tissue repair, protein synthesis, and growth hormone secretion takes place during sleep. Most of the rejuvenating effects of sleep are specific to the brain and cognitive function.

The purpose of sleep remains to be one of the greatest unanswered mysteries even in today’s modern and technologically advanced world. Even though the reason why we sleep is still unknown, sleep still has a very crucial role in maintaining our overall health and well-being.