How Sleep Affects Immune Function
In this day and age, getting enough sleep can feel like an impossible endeavor. Between busy social and professional lives and running a household and raising children, many people don’t get the adequate amount or quality of sleep that they need for their body to be well rested and restored.
The problem with not getting enough sleep is that it can severely impact your health in a variety of ways. Research has shown that a lack of shut-eye is closely related to an increased risk of conditions such as high blood pressure, diabetes, heart attack, and stroke. While having one bad night of sleep isn’t going to increase that risk, chronic sleep deprivation will. But how does sleep affect the immune system? And how can we make sure we’re getting enough? Read on to learn all you need to know about how sleep affects immune function.
Sleep and immunity
To understand how sleep affects immunity, we first need to understand what sleep does for the body overall. Research has found that sleep and immunity are closely tied because of the body’s circadian rhythm. Otherwise known as the circadian cycle, this the internal clock that everyone has within their body. It regulates the sleep-wake cycle, acting as a sort of guide or cue as to when it’s time to sleep and when it’s time to wake up. It helps the body refresh itself from the activities and energy loss of the day.
Studies have found that each person’s circadian rhythm has strong influence over the immune system and how it functions. Primarily, it maintains regulatory processes over the normal sleep-wake cycle that the production of immune cells relies upon. For example: T-cells are designed to fight off infection, and the circadian rhythm helps to release them into the blood so they can be distributed throughout the body where they need to go.
Sleep also influences cytokines, which are immune proteins that aid in cell signaling throughout the body. They help the immune system control the growth and activity of blood cells and other immune cells that have specific jobs to do to ward off sickness. When cytokines are released, they act as an alert system for the immune system, prompting it to respond to whatever pathogen has entered the body. Because of the way sleep affects these cytokines, it actually drives a healthier immune response.
How much does sleep boost the immune system?
While the simple act of sleeping doesn’t boost the immune system as such, recent research has found that it is more vital than once thought. Researchers have recently discovered a specific area of the immune system that is vital to its function and greatly affected by sleep.
The study in question looked at T-cells, the immune cells mentioned above. They are designed to fight against intracellular pathogens, which can grow and produce inside the cells of their host. Examples of these types of pathogens include cancers and viruses such as the flu. Sleep can actually help you battle these types of pathogens because of its contribution to those T-cells.
T-cells rely heavily on a type of adhesion molecule known as integrins to be able to “stick to” pathogen cells and help get rid of them. And guess what? That “stickiness” found on certain molecules that help to bring a T-cell to an infected cell is stronger while you’re sleeping.
Sleep is also the time when the majority of immune cells peak in certain areas of the body, such as the peripheral blood and lymph nodes. This has a lot to do with cortisol levels. The T-cell rhythm is heavily linked to the rhythm of cortisol. While cortisol peaks just after you wake, T-cells peak just after you fall asleep. This is important because high levels of stress hormones actually cause the adhesiveness of integrins to become weaker. This makes it more difficult for T-cells to get into contact with pathogens they need to neutralize.
Does sleep deprivation affect the immune system?
While everyone is different, it’s suggested that adults get at least seven hours of quality sleep each night to be able to reap the rewards of rest. The problem is that, according to the Centers for Disease Control and Prevention, over 30% of Americans aren’t getting nearly enough sleep. This puts a large chunk of the population at risk for chronic disease and severe illness.
The issue here is that since there’s so much going on while you’re sleeping when it comes to your immune health, not getting enough sleep is taking away valuable time for your body to replenish and regulate the immune cells needed to fight off infection. When you’re awake, the body’s pro-inflammatory response (designed to single out harmful substances or pathogens) is also disrupted because of stress hormones. Research has found that these hormones may act in an anti-inflammatory way. Because of this, the vital action of pro-inflammatory cytokines is hindered when a person does not get enough sleep.
To put it simply: sleep is crucial for a well-functioning immune system. It may even be one of the most important aspects of keeping your body free from infection. Considering the ongoing pandemic and the fact that it’s cold and flu season in many areas, there has never been a better time to make sure you get more sleep.