The role of sleep in maintaining overall health cannot be emphasised enough. Researchers have time and again demonstrated the importance of quality sleep and how it can contribute to numerous aspects of physical and mental well-being.
Disturbed or inadequate sleep has a definite impact on the likelihood of developing numerous health conditions, various sleep disorders, as well as the individual’s ability to recover. Further, there is a direct connection between sleep and heart too. Adults who sleep for less than 7 hours at night are more likely to have health problems, including heart attack, asthma and more.
Recent studies have also shown that sleep contributes to the proper functioning of the immune system. Not having an adequate amount of sleep could adversely affect your immune system, making you more susceptible to illnesses such as common cold or flu.
Researchers in these studies found a mechanism linking sleep to the functioning of the immune system and how sound sleep improves immune cells known as T cells.
The Importance of T Cells
The T cells are essentially a type of immune cells that fight against intracellular pathogens, for example, cancer cells, HIV and virus-infected cells such as the flu.
These T cells play an important role in the body’s immune system.
When T cells in the body recognize a virus infected cell, they activate integrins- a sticky type of protein- that then allows them to attach themselves to the cells and kill all such infected cells.
Studies show that people who sleep well at night have T cells with higher levels of integrin activation as compared to the T cells of those who were awake during night time.
This conclusively proves that the number of sleep hours has the potential to improve the functioning of T cells in the body. In case of inadequate sleep, stress hormones can inhibit the ability of T cells to function to kill pathogens effectively.
How Sleep Affects The Immune System-The Mechanism
In our body, there are two prominent stress hormones- adrenaline and noradrenaline (also known as epinephrine and norepinephrine). These stress hormones, along with pro-inflammatory molecules, prostaglandins, completely inhibit the stickiness of a class of adhesion molecules called integrins.
During the sleep hours at night, the adrenaline, noradrenaline and prostaglandins levels are low leading to strong stickiness of the integrins.
This stickiness is really important because for T cells to be able to kill virus-infected cells or cancer cells, they need to get in direct contact with them, and the integrin stickiness help to promote this contact.
Interrelation Between, Brain, Sleep and The immune system
A study suggests that approximately 1 in 4 people experience some sort of sleep disturbance leading to various sleep disorders. A good sleep at night helps the body redistribute all the energy resources that are primarily used for brain and muscle work to the immune system.
When we sleep, the immune cells of the body get out of the circulation, settle in the lymph nodes, and slowly start getting ready for the next day of work.
Parallelly, something similar happens in the brain when it recharges and cleans itself from all kinds of toxic waste of the day, which can otherwise cause inflammation. When we sleep, adrenaline and cortisol levels drop, while melatonin rises. This, in turn, helps to counteract inflammation in the body by reducing reactive oxygen species, a kind of damaging molecule.
Sleeping better at night helps to create a synchronised combination of immune system and hormones to enable the body to take extra energy from the muscles and then utilise it for building up and maintaining a healthy immune system.
Sleep isn’t just essential for your immunity. There was research done in people who don’t sleep well, and it was found that they are more anxious and have double the risk of suffering from depression.
Role of Cytokines
During sleep, our immune system releases a sleep-promoting protein called cytokines.
Without sufficient sleep, our body makes fewer cytokines- that target infection and inflammation-effectively, creating an immune response.
Further, there are certain cytokines which need to increase in case of any kind of infection or inflammation, or when we are under stress. If we do not get a good nights’ sleep, it may decrease the production of protective cytokines along with the reduction in the infection-fighting antibodies and cells.
Put simply, our body needs sound sleep during the night to be able to fight infectious diseases. Sleep deprivation for a long time also enhances the risk of several other ailments, including diabetes, obesity, and other cardiovascular diseases.
Sleep Deprivation and the Immune System
Have you ever wondered about the correlation between lack of sleep and getting sick?
A lot of people get sick when they do not get enough sleep. There have been various studies to inspect and verify how this connection works, and some of them are discussed below-
- Changes in white blood cells
Researchers performed a study and found the changes in the white blood cells after the loss of sleep. Performed on a small group of people, it was found during the first week that with good sleep for eight hours per night and limited intake of coffee and alcohol, they established a healthy circadian rhythm.This was followed by a week of sleep deprivation, and it was found that the number of granulocytes or white blood cells increased in a reaction to the stress caused by sleep deprivation. The study leads to a better understanding of how poor sleep breaks down immunity and makes people sick.
- Different sleeping patterns
In a second study, University of Washington researchers followed secure pairs of identical twins with different sleeping patterns with the conclusion that the twin who was sleeping less had a much weakened immune system.
The study showed that the immune system works best when the body is well-rested, including the need for seven-eight hours of regular sleep.
- Sleep hours affecting T cells
Researchers from Tuebingen, Germany, studied the effects of sleep on the immune system’s T cells.
After comparing and analysing the T cells from patients who were awake and from those who were sleeping it was found that the samples of T cells in the former case had a higher level of integrin activation as compared to the ones who were wide awake. That result was a clear indication of the fact that sleep has a positive effect on the functioning of T cells as a part of the immune system.
What Is the Right Amount of Sleep Needed to Bolster the Immune System?
In the case of adults, the optimal amount of sleep required is seven to eight hours, whereas teenagers need nine to 10 hours of quality sleep hours.
This will keep your immune system in good shape to fight infections and also protect you from various sleep deprivation and health issues including diabetes, heart disease, obesity and more.
In case of interrupted sleep due to busy work schedules, it is recommended to take two naps, no longer than 30 minutes each (one in the morning and one in the afternoon) to help you decrease stress and counter the negative effects caused by sleep deprivation on the immune system.
It is, however, important to note that sleeping for extended hours (more than 7–8 hours in adults) isn’t always better. It may result in fatigue, laziness or difficulty falling or staying asleep.
How to Get Enough Sleep
To be able to sleep better at night, it is important to follow certain sleep hygiene tips. Some of these include-
- Maintain a consistent bedtime routine
First and foremost, make sure to go to bed at the same time every day to help the body become used to the schedule and feel tired when it’s bedtime and awake in the morning.
- Choose your mattress wisely
The quality of your sleep is heavily dependent on the choice of mattress. For a night of proper rest and sleep, it is essential to find the one that perfectly suits your needs and body preferences.
- Exercise on a regular basis
This is another great way to beat the everyday stress and train the body to feel tired and rest at bedtime. The best time to practise exercise is afternoon or early morning.
Wrapping Up
Sleep is considered as an essential modulator of the immune response on our body. It can not only bolster the T cells in the body that fight off infection by enhancing their ability to adhere to cells infected by viruses and other pathogens but also improves the overall health.
A lack of sleep can weaken immunity and increase the susceptibility to infection. For example, lack of sleep is generally associated with a rise in suffering from the common cold.
However, there’s much more to boosting your immunity than just getting a good amount of sleep. Practising smart and healthy strategies such as maintaining hygiene, washing your hands regularly, avoiding close contact with people with infections, and visiting your doctor for regular flu shots is important too. Just remember that a well-rested body allows the body to bounce back much faster from seasonal infections to let you live a healthy and happy life.
