Sleep science has come a long way in the last several decades, shedding light on sleep’s crucial role in maintaining the health of the body’s myriad of intricate systems. Research into the correlations between sleep and health has revealed a strong association between sleep and the immune system.
Overall health depends on a strong immune system. It has a crucial role in mending wounds, preventing infections, and warding off chronic and fatal diseases.
There are two-way connections between sleep and the immune system. Insomnia may be brought on by an immune reaction, such as that brought on by a viral infection. Further, regular sleep helps the immune system to perform more efficiently and effectively.
However, sleep deprivation has been shown to disrupt immunological function. Sleep deprivation has been shown to be harmful both in the short and long term.
What is the optimal amount of sleep?
To get the most out of your beauty rest, try according to these guidelines from the National Sleep Foundation.
- Newborns (0-3 months): 14-17 hours.
- 12- 15 hours for babies (4-11 months).
- In the range of 11-14 hours for toddlers (ages 1-2).
- Children ages 3 to 5 years old require 10-13 hours of sleep per night.
- Children between the ages of 6 and 13 usually spend between 9 and 11 hours a day in school.
14-17 year olds: 8-10 hours
- Teens and young adults (18-25): 7–9 hours.
- Seven to nine hours for adults (aged 26-64).
- Seven to eight hours for those over the age of 65.
Although the aforementioned figures represent the recommended minimum and maximum amounts of sleep for certain situations, there are times when more sleep is required.
How Does the Immune System Work?
The immune system is a multifaceted network that protects the body from pathogens. Innate immunity and adaptive immunity are the two primary types of defenses that humans employ. As a wide form of defense, with multiple levels, innate immunity is extremely effective. Protections that you build up over time and that are aimed at certain risks are part of adaptive immunity, also known as acquired immunity.
Understanding the Immune System
The immune system is incredibly intricate due to the many parts that make it up. White blood cells (leukocytes) play a crucial role in our immune system. The function of the leukocyte is to locate, invade, and expel invading microorganisms. Because of the rapid (innate) and trained (adaptive) responses of the immune system, we can safely engage in daily environmental interactions.
Cytokines are proteins released by white blood cells in response to the presence of a foreign pathogen, alerting other white blood cells to be ready to launch an attack. In the immune system, cytokines serve as messenger proteins. Aside from white blood cells, immunological reactions like swelling and redness involve other substances like histamine.
Balanced Immune Response
When healthy, the immune system keeps everything in fine balance. The body’s immune system responds to danger or harm by causing symptoms like redness, inflammation (swelling), exhaustion, fever, and discomfort.
The immune system needs to be robust enough to identify and eliminate dangers, but it also needs to be properly controlled so that the body is not perpetually on high alert.
Insomnia and its consequences
Insomnia is defined as the inability to fall asleep, even when tired. The following are some signs that someone has insomnia:
- fatigue and drowsiness even in the middle of the day.
- Is perpetually aggravated.
- Struggle with concentration and remembering information.
Long-term sleep loss is associated with an increased threat of developing diabetes, heart disease, and obesity. Lack of sleep can impair the body’s immune response, making it more vulnerable to infection and less effective at fighting off illness.
Sleep can affect how our immune cells function
The cells that defend your body can be organized into armies, each with its own specialized forces. While it would be impossible to provide comprehensive information on every type of cell, protein, and molecule involved in sleep, we have included some background on the most prominent and frequently discussed ones.
One type of white blood cell, T cells can either aid the body’s immune system or attack foreign invaders. When a foreign organism enters the body, helper T cells send out a warning signal.
They alert nearby immune cells that an attack is happening and that assistance is required by releasing chemical signals.
In the fight against infection, cytotoxic T cells play a more direct role. They are able to identify infected cells and destroy them by attaching themselves to them in a variety of ways.
T cells from volunteers who were allowed to sleep for 8 hours a night were shown to have a substantially lesser ability to bind to a crucial molecule included in the immune response when compared to T cells from individuals who stayed awake all night, proving the importance of sleep.
A T cell’s primary goal is to bind to infected cells and other immune system cells, as we discussed previously. They can’t play their part in the immune response unless they have the ability to adhere.
It is clear from the results of this study that sleep deprivation has an effect on our immunological response.
Aside from neutrophils, B cells are also present in the blood and actively seek out and destroy foreign invaders.
Antibodies on the surface of B cells allow them to bind to foreign substances, including infections. The antibody can be pictured as a missing piece of a jigsaw puzzle. One half of a two-part jigsaw puzzle can be found on the B cell’s surface.
Whenever a free-floating B cell encounters a virus or bacteria that also happens to contain the missing piece of the jigsaw on its surface, the B cell bonds to the foreign invader. It means that an enemy invasion has been identified and will be destroyed shortly.
Helper T cells can bind to B cells to allow them to secrete multiple copies of their specific antibody. When released, the antibody will seek out and destroy any microbes for which it has a special affinity.
They can also develop into memory B cells, which can “remember” a particular infection and respond correctly the next time they encounter it.
There are cells in the body called natural killer (NK) cells, and their job is to kill infected cells. They trigger programmed cell death, wherein the infected cell essentially kills itself, by secreting substances that send the signal.
The average activity of natural killer cells (NK cells) was found to be reduced by 72% following only one night of sleep duration reduced to four hours compared to the levels after a full night’s sleep.
Researchers have found that a 1.6-fold increase in the chance of dying from cancer is connected with a reduction in NK cell activity, which plays a crucial role in destroying tumor cells.
Some of the white blood cells in the body can engulf and digest any bacteria, viruses, or parasites they come across.
When pathogens invade these cells, phagocytes use a variety of techniques to degrade and eliminate them. Each phagocyte subtype has its own specialized niche and set of abilities:
- Large numbers of neutrophils can be seen in the circulation, and they are the first immune cells to reach an infected region.
- Macrophages — can cross out of blood arteries to combat infections in other parts of the body.
- Tissue dendritic cells play an important role in bridging the gap between the innate and acquired immune responses.
The aforementioned cells not only perform the enumerated functions, but also engage in extensive mutual support and communication.
Small proteins called cytokines are secreted by your immune cells and many others and play a crucial role in the immune response.
The immune response’s various cells are able to “communicate” with one another thanks to cytokines, which work as little messengers to bring immune cells to the site of the invasion and reinforce the signs that an attack is occurring.
The immune system relies on cytokines, which come in a wide variety of families and subgroups and have a wide variety of functions.
Reducing sleep time has been linked to the production of inflammatory cytokines, which are thought to contribute to the onset of cardiovascular, vascular, and metabolic diseases.
How Does Sleep Affect the Immune System?
The immune system greatly benefits from a good night’s sleep. A strong immune system, including robust innate and adaptive immunity, an effective response to immunizations, and less allergy reactions, is made possible by getting enough high-quality sleep.
Sleep disorders such as insomnia, sleep apnea, and disruption of the circadian rhythm, on the other hand, can have negative effects on the immune system.
Sleep and Innate and Adaptive Immunity
Sleep is a critical time for the body to recharge, and research shows that it also plays a major part in maintaining a healthy immune system. In reality, sleep helps with both kinds of immunity, innate and adaptive.
Certain parts of the immune system are discovered to be activated as people sleep, according to studies. Inflammation, for instance, is linked to a rise in cytokine production. Both sleep and circadian rhythm (the body’s 24-hour internal clock) appear to play a role in this behavior.
During times of illness or injury, the body’s inflammatory response may aid in the healing process by bolstering the patient’s innate and adaptive immune systems.
But research has shown that this inflammation can take place even if a person isn’t experiencing any obvious signs of injury or illness at the time. This immunological activity occurs at night, and research into the cells and cytokines involved suggests that it serves to bolster adaptive immunity.
Research reveals that sleep reinforces immunological memory in the same way as it does for learning and memory. The immune system’s ability to remember how to recognize and react to harmful antigens is bolstered by the interaction of immune system components during sleep.
Though the precise mechanism(s) at play during sleep is unknown, various elements are speculated.
- The immune system is able to focus on its vital functions since breathing and muscle activity decrease down during sleep.
- Because inflammation during sleep has been shown to impair both physical and mental performance if it occurs during the day, the body has adapted to have this process take place only at night.
- Inflammation can cause stress that can be ameliorated by the production of melatonin, a hormone that is secreted at night and promotes sleep.
An important feature of this self-regulating process is the positive effect it has on the immune system. The circadian clock of the body reduces this inflammation as the sleep period nears its end. This is because both innate and adaptive immunity rely on a finely tuned balancing act that is greatly aided by receiving adequate high-quality sleep.
Sleep and Vaccines
The benefits of sleep for adaptive immunity have been demonstrated by numerous studies. Sleep increases the efficiency of vaccines.
Vaccines prime the immune system by introducing a tamed or inert version of the infectious agent. Immunizations work because they train the immune system to recognize and attack a specific antigen.
How well vaccines work is in part determined by how well their recipients sleep. The immunological response is suppressed the day following vaccination, according to studies of hepatitis and swine flu (H1N1) vaccinations. This can lessen the effectiveness of the vaccine and even necessitate a booster shot.
Other studies have found decreased vaccine effectiveness in people who routinely fail to receive at least seven hours of sleep every night, albeit those trials did not entail total sleep deprivation after vaccination. If a person doesn’t get enough shut-eye, their immune system won’t have time to form a memory of the vaccination and will likely be ineffective against the disease.
Sleep and Allergies
There is mounting evidence linking sleep disruptions to allergic reactions, which occur when the immune system overreacts to a substance that poses no threat to the vast majority of people.
Recent studies have shown that an individual’s circadian rhythm plays a role in controlling the body’s response to allergens. There may be a correlation between a disruption in the circadian rhythm and an increase in the incidence and severity of allergic reactions.
Allergies and a lack of sleep have been linked together. One study indicated that patients with peanut allergies were 45 percent more likely to have an allergic reaction to peanuts if they had not slept the night before.
Can Sleep Deprivation Make You Sick?
Sleep deprivation has far-reaching consequences on health, and growing evidence suggests it might damage the immune system and make you more susceptible to illness.
Short-term ailments and the development of long-term conditions like diabetes and heart disease have both been linked to insufficient regular sleep. More and more studies point to the link between sleep deprivation and impaired immune function as the underlying cause.
People who get less than six or seven hours of sleep every night have been proven to have a higher risk of infection in the short run. Lack of sleep has been shown to increase susceptibility to viral infections including the common cold and influenza. Lack of sleep can also slow the recovery of persons in intensive care units (ICUs) who need to recover from serious injuries or illnesses quickly.
Numerous long-term health issues have been linked to sleep loss, which is likely due to the deleterious effects of sleep deprivation on the immune system. When people have a good night’s rest, their inflammation levels return to normal overnight. Sleep deprivation, however, prevents this normally self-regulating system from working properly, leading to persistent inflammation.
The body nonetheless pays a price for this chronic low-grade inflammation, which has been linked to an increased risk of diabetes, cardiovascular disease, pain, and neurological illnesses. The increased prevalence of depression among persons who have trouble sleeping may be due to the link between chronic inflammation and this mood illness. Animal studies have shown that not getting enough sleep can make inflammation, which is linked to cancer, much worse.
While it’s true that some may function on less sleep than others, research shows that the immune system never “gets used to” being under-rested. Instead, this chronic low-grade inflammation can harm health in the long run.
How the Immune System Affects Sleep
Despite the importance of sleep to immune function, there are several ways in which the immune system can disrupt the quality of one’s zzz’s.
The immune system has many responses to infections, and one of them is fatigue and sleepiness. When sick, this is one of the many causes of people staying in bed more than usual.
Infection also alters the structure of sleep, changing how much time is spent in each stage. In particular, the immunological response increases the amount of time spent in deep sleep (stage 3 of NREM sleep). As more bodily processes are slowed down during deep sleep, the immune system is able to devote more resources to fighting off infection.
The body’s immune system also responds with a fever. In addition to making the body more hostile to many infections, an increase in core body temperature can initiate additional waves of immunological protection. The altered sleep patterns brought on by infection are thought by some to aid in the body’s fever and its defense against invading microorganisms.
Since our metabolism is at its lowest during deep sleep (N3 stage), this theory suggests that during an infection, we sleep more during this stage so that we have more energy to build a vigorous fever response. Shivering helps with both heat loss and keeping a fever up. Due to muscular atonia, our bodies are unable to shiver during REM sleep, thus eliminating this stage of sleep during an active infection. Fever dreams, or an increase in nightmares, are attributed to the disruption of REM sleep that occurs with fever.
These effects show how closely sleep and the immune system are linked, and how the immune system can use sleep to increase its ability to fight infection, which is still being studied by scientists.
Can good sleep improve immunity?
Although getting a good night’s sleep can improve your immune response, getting a bad one can lower it. The performance of T helper cells is boosted by getting enough high-quality sleep. As part of the body’s immune response, T helper cells destroy invading bacteria, viruses, or other foreign antigen cells.
Integrin is a protein released by immune cells upon recognition of a foreign pathogen. As a result of integrating with foreign antigens, T cells are able to be destroyed.
Researchers found that T cells activate integrins and pinpoint factors that reduce T cell attachment effectiveness to the target pathogen in a study published in the Journal of Experimental Medicine.
Hormones such as adrenaline and noradrenaline and pro-inflammatory chemicals like prostaglandins were shown to prevent T cells from combining with integrins. While you sleep, your levels of adrenaline, noradrenaline, and prostaglandins naturally drop. Thus, adequate sleep enhances the effectiveness of T cells and strengthens the immunological response of the body.
It’s common knowledge that getting enough sleep is beneficial. Every person needs to make getting sufficient sleep a top priority. Maintaining proper sleep hygiene, such as sleeping in a cool, dark room free of devices, can aid in getting a good night’s rest. Improving the quality of your sleep can also be accomplished by engaging in regular physical activity and refraining from consuming alcohol or caffeine.
How Can You Improve Sleep and Strengthen Your Immune System?
Since sleep is crucial to immune system performance, prioritizing regular, restful slumber as a means to fortify your defenses against illness is sound advice.
Focusing on these factors—your habits, routines, sleeping environment, and even if you have the ideal mattress for your needs—is a good place to start when trying to improve your sleep quality. The term “sleep hygiene” refers to a collection of practices that can improve your chances of getting a restful night’s rest. These practices include sticking to a regular sleep schedule and putting down electronic devices at least an hour before bedtime.
In the event of severe or persistent insomnia or recurrent health problems, medical attention should be sought. A physician’s job is to seek out the root of the problem and devise a plan to treat it.
Cognitive behavioral therapy for insomnia is one potential treatment option for people with sleep difficulties (CBT-I). This method is effective at alleviating sleep anxiety, facilitating restful slumber, and lowering inflammatory markers.
Yoga and tai chi are two examples of mind-body practices that have been demonstrated to help people relax and sleep better, both of which are beneficial for immune system health.