Why do we Sleep?

This is a guest post by Ms.Darshini Shah (dnshah1@gmail.com)

As humans, we spend one-third of our lives sleeping, yet science has not revealed the reason behind our sleep (Harvard Medical School).  Scientists have drawn several central theories that examine understanding the need for sleep.

 The adaptive/evolutionary theory postulates that we are inactive at night and the transition from active and inactive sleep is essentially to conserve energy.  Conversely, a counterpoint argues that being awake and conscious is vital for safety and security.

            The energy conservation theory, considers that the main purpose to sleep is to conserve one’s energy demand and expenditure during periods in the night and day (Harvard Medical School).  Some scientists associate this theory with the adaptive/evolutionary one. The research has shown that metabolism levels reduce by 10 percent in humans when sleeping, and include body temperature and caloric demand (Harvard Medical School). 

            The restorative theory suggests that sleep revitalizes and restores our body and physiological responses, such as muscle growth, tissue repair, protein synthesis, and hormone release (Harvard Medical School).  Moreover, this theory also factors in cognitive functioning in the restoration and repair.  A recent study in October 2013, the findings had shown that the brain carries out a flushing of waste toxins during sleep.  The study purports that this removal in turn relates to human sleep.  More specifically, neurotoxic waste materials that collect in the awake central nervous system are removed through this restorative function of sleep.

            The last theory, brain plasticity, corresponds with the structure and organizational framework of the brain (Harvard Medical School).  This theory stresses that sleep is instrumental in brain development, from infants to adults who are sleep deprived and in relation to their learning and performance of tasks.

            In concluding, these theories do not fully evaluate the reason humans sleep, as there is no research support for each theory. Scientists have, however, construed that sleep has many important functions, namely sharpening one’s memory, increasing one’s lifespan, better quality of life, decreasing inflammation (e.g. that is associated with heart disease, stroke, diabetes, arthritis, and premature aging), triggering creativity, improving attention, concentration, and learning, decreases stress, immune and metabolism, and other critical functions.

Reference

http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/why-do-we-sleep

This is a guest post by Ms.Darshini Shah