We’ve always been told how important sleep is, and yet, we often think of it as simply a recharging session. We hit the sack to rest, and not many are aware of what goes on inside the body when we are in slumber. How important is sleep? What happens when you don’t get enough of it? The answers to these and more below.
Why Do You Need to Sleep Anyway?
There’s a multitude of reasons why health experts consider sleep as a survival necessity like food and water. One of these reasons is when we sleep, several vital biological processes happen. (1)
Here’s a quick breakdown:
- Cellular Restoration – The Restorative Theory talks about how the body restores and heals itself when sleeping. Muscle and tissue cells undergo regrowth and repair. The body releases hormones and protein synthesis occur.
- Brain Functioning – For proper brain function, sleep is crucial. According to the Brain Plasticity Theory, sleep allows the nerve cells in the brain to reorganize and communicate with each other, which helps improve brain health. Further, this is the time the brain detoxes as the glymphatic system removes all the waste material that built-up through the day. Proper sleep affects memory, focus, concentration, learning, problem-solving, decision-making, and creativity.
- Energy Conservation – According to the Energy Conservation Theory, the body restores energy during sleep. As the body’s metabolic rate goes down during this time, the body can save more energy for activities after waking up.
- Insulin Function – Insulin is important in converting glucose to energy. With lack of sleep, insulin resistance can happen where the body no longer uses insulin correctly. As a result, the blood glucose level shoots up, which can result in diabetes. To add, sleep helps regulate blood glucose since the brain uses less energy during this time.
- Weight Management – Hunger hormones are tamed during sleep due to reduced energy consumption. On the other hand, the opposite happens when there’s a lack of sleep. Ghrelin, the appetite hormone increases upon waking, and so does leptin, the satiety hormone.
- Cardiovascular Health – Lack of sleep is linked to heart problems such as inflammation, high blood pressure, increased production of cortisol, and increased sympathetic nervous system activity, which accelerates the heart rate.
- Emotions – As the brain rests, so do the areas that maintain emotions like the amygdala, hippocampus, medial prefrontal cortex, striatum, and insula. Sleep is essential to stabilize emotions. For instance, if a person is well-rested, his amygdala will be more equipped to respond to a stressful situation and overreact.
- Immune System – The body produces cytokines during sleep, and these are important for fighting infections and inflammation in the body. Also, the body produces more antibodies when it’s at rest – more on this in the next section.
How Does Sleep Affect Immunity?
The short answer is it has a huge effect. The long answer is it has something to do with T cells. T cells are a type of immune cells that fight off cancer cells and pathogens. They also help the body to fight off infection.
A study exhibiting the connection between immunity and sleep shows how and why T cells perform better when the body is sleeping.
“Because the levels of adrenaline, noradrenaline, and prostaglandins are low during sleep time, the stickiness of the integrins is stronger. This stickiness is important because for T cells to kill virus-infected cells or cancer cells, they need to get in direct contact with them, and the integrin stickiness is known to promote this contact.”
The importance of T cells and sleep in the human body is unparalleled. Researchers compared the T cells between healthcare workers who slept and those who stayed awake all night. The findings showed that the well-rested workers showed higher integrin activation to those who didn’t. (2)
Another factor to consider is that lack of sleep makes a person more stressed out. Poor sleep leads to the production of more stress hormones or cortisol, which then affects the proper functioning of T cells.
How Many Hours of Sleep Does One Need?
According to the National Sleep Foundation, these are the recommended hours:
- Newborn-3 months: 14-17 hours
- 4-11 months: 12-15 hours
- 1-2 years: 11-14 hours
- 3-5 years: 10-13 hours
- 6-13 years: 9-11 hours
- 14-17 years: 8-10 hours
- 18-64 years: 7-9 hours
- 65-older: 7-8 hours
What Factors Affects Sleep?
There are plenty of reasons why people don’t get enough sleep. For some, they choose productivity over rest. They continue to work late hours to meet a deadline and put off sleeping. On the other hand, there are those whose body clocks are going in the opposite direction, which then leads to a host of health problems because the organ systems are not functioning at their peak.
John Hopkins neurologist and sleep expert Mark Wu say that sleep drive and circadian rhythm play big roles in sleep regulation. He refers to sleep drive as the body’s craving for sleep just how it does with food. Throughout the day, this drive builds up as an individual uses up energy. By night time, the body is exhausted and ready for rest.
The circadian rhythm of the body responds to light cues because it produces more melatonin at night, preparing the body for sleep. However, people who work night shifts sleep during the day, which can be very challenging.
Additionally, Wu mentioned the “wide awake” gene, indicating that there’s a gene that affects the circadian rhythm of the body. He studied fruit flies and when he removed this gene, the fruit flies had trouble sleeping. Humans have this gene, too, yet there is more research to be done on how this affects sleep in humans.
The Consequences of Lack of Sleep
As much as there are positive effects of getting a good shut-eye, lack of sleep leads to adverse health effects. For one, people who don’t sleep the recommended hours can already be in a fight-or-flight state the moment they wake up. They’re going through the day with high adrenaline and increase cortisol levels in the body.
There are also short and long-term effects of poor sleep. Short-term effects include memory problems, moodiness, poor judgment, and sleepiness, which makes individuals prone to committing more mistakes. Lack of sleep also puts people behind the wheel more at risk of causing car accidents.
Long-term effects will affect how the brain functions as well as problems with emotions, insulin resistance, and the heart. All of which can bring about more health problems in the long run.
People should realize that poor sleep builds up. If a person doesn’t have proper sleep for three days, that equates to an entire night without sleep. Moreover, sleeping less than six hours a day is associated with early death, according to the NHS. (3)
How to Sleep Better
There are plenty of reasons why people don’t get enough sleep. For some, they choose productivity over rest. They continue to work late hours to meet a deadline and put off sleeping. On the other hand, there are those whose body clocks are going in the opposite direction, which then leads to a host of health problems because the organ systems are not functioning at their peak.
John Hopkins neurologist and sleep expert Mark Wu say that sleep drive and circadian rhythm play big roles in sleep regulation. He refers to sleep drive as the body’s craving for sleep just how it does with food. Throughout the day, this drive builds up as an individual uses up energy. By night time, the body is exhausted and ready for rest.
The circadian rhythm of the body responds to light cues because it produces more melatonin at night, preparing the body for sleep. However, people who work night shifts sleep during the day, which can be very challenging.
Additionally, Wu mentioned the “wide awake” gene, indicating that there’s a gene that affects the circadian rhythm of the body. He studied fruit flies and when he removed this gene, the fruit flies had trouble sleeping. Humans have this gene, too, yet there is more research to be done on how this affects sleep in humans.
The Consequences of Lack of Sleep
As much as there are positive effects of getting a good shut-eye, lack of sleep leads to adverse health effects. For one, people who don’t sleep the recommended hours can already be in a fight-or-flight state the moment they wake up. They’re going through the day with high adrenaline and increase cortisol levels in the body.
There are also short and long-term effects of poor sleep. Short-term effects include memory problems, moodiness, poor judgment, and sleepiness, which makes individuals prone to committing more mistakes. Lack of sleep also puts people behind the wheel more at risk of causing car accidents.
Long-term effects will affect how the brain functions as well as problems with emotions, insulin resistance, and the heart. All of which can bring about more health problems in the long run.
People should realize that poor sleep builds up. If a person doesn’t have proper sleep for three days, that equates to an entire night without sleep. Moreover, sleeping less than six hours a day is associated with early death, according to the NHS. (3)