Beyond Bedtime
By Katie Mayer
It is a widely-known fact that sleep is beneficial for your well-being and conversely that the lack thereof causes health risks. But have you ever considered how a simple habit can affect your life both physically and mentally?
Researchers have found that middle-aged adults need about 7-9 hours of sleep per night, and even more if they are younger to maintain good health and bodily performance. Sleep is more than just a rest state; it is an extremely complex process of your body internalizing the happenings and interactions of the day. During rest, the body repairs itself, allows the immune system to fight off invaders and undergoes the most growth and development.
Sleep is divided into two different types, Rapid Eye Movement (REM) and non-Rapid Eye Movement (non-REM). Non-REM has four parts, which involve falling asleep, light sleeping where heart rate and breathing slows and finally deep sleep in the third and fourth stages. In REM sleep, arguably the most important type of sleep, your eyes rapidly dart around behind your eyelids (hence the name) and dreaming occurs as your body consolidates memories, learning and making sense of the world.
These cycles repeat until the morning when you wake. Without proper sleep, your brain is unable to perform and retain “brain plasticity”, or the ability to adapt to input during the day. Brain plasticity allows us to process information and remember it.
During sleep, the brain removes toxic waste. Jonathan Kipnis, Ph.D., Professor of Pathology & Immunology at Washington University School of Medicine in St. Louis states that without the disposal of these metabolic wastes, it would lead to neurodegenerative diseases, such as Parkinson's Disease, Alzheimer's Disease, and dementia.
Additionally, the Wisconsin Sleep Cohort Study connected the relationship between sleep and obesity. Researchers found that adults with 7.7 hours of sleep each night had the lowest body mass index (BMI).
They found that anything more or less than 7.7 hours of sleep per night contributes to higher BMIs, which is due to two major appetite-related hormones, leptin and ghrelin. Leptin suppresses appetite, while ghrelin stimulates it. With inadequate sleep, patients presented with lower levels of leptin and higher levels of ghrelin.
Obesity also contributes to obstructive sleep apnea (OSA), which is a sleep disorder that obstructs or partially obstructs the airway, resulting in a lack of oxygen. This is attributed to more fat distribution in the airways, which causes them to become more narrow, thus restricting airflow.
Sleep loss is also associated with diabetes and impaired glucose tolerance. Impaired glucose tolerance is the predecessor of diabetes, and occurs when glucose levels are elevated for an extended period of time. Another study found that adults who slept 5 hours of sleep or less per night, were 2.5 times more likely to have diabetes than those who slept the recommended 7-8 hours a night.
Similarly, sleep loss is correlated with myocardial infarction, also known as heart attacks. Multiple studies concluded that five hours of sleep or less resulted in a 45% increase in the risk of having a heart attack. Inversely, sleeping for 9 hours or more presented slightly lower, but similar risks. The risks are even higher if your lack of sleep is also contributing to high blood pressure or glucose intolerance.
Psychologically, sleep plays a major role in one’s mood and mental health. One particular study on high schoolers found that those who had self-reported sleep loss presented more depressive symptoms and had lower self-esteem than their counterparts who were getting the recommended 7-8 hours of sleep. Researchers are still unsure if sleep plays a rike in mood and depression or vice-versa, but an association is still present.
Overall, sleep is extremely important for both mental health and physical health. Mortality rates increase by about 15% in those who continuously get 5 hours of sleep or less, and unfortunately, there is no “catching up on sleep.”
If you are experiencing a lack of sleep, professionals urge you to sleep longer and to take short naps. Understanding proper sleeping habits is imperative to good health both physically and mentally.