How Sleep Strengthens Your Immune System

There’s a surefire way to decrease your chances of getting sick this winter, and the good news is it’s so easy you can do it with your eyes closed: getting consistently healthy sleep.

Poor sleep = bad news

In a recent interview with CNN, sleep scientist Matthew Walker said that studies show individuals sleeping less than 7 hours a night are three times more likely to become infected by the rhinovirus, more commonly known as the common cold. He then added that individuals sleeping 5 or less hours a night are 70% more likely to contract pneumonia, which is dangerous on its own, but also a complicating factor in those with coronavirus. 

And sleep deprivation doesn’t just increase your chances of getting sick, Walker tells us, but it has also been proven to weaken the effect of vaccines. Citing a study from The Journal of the American Medical Association, he notes that getting insufficient sleep the week before getting a flu shot can decrease antibody production by up to 50%—meaning your body is less prepared to defend you from the different strains of influenza.

But why in the world does sleep matter so much to your immune system?

Sleep—your immune system’s support system

As we always like to remind folks, sleep is the very foundation of your physical and mental health. Leave the foundation too thin or inconsistent for long enough, and the whole building tends to start crumbling.

To put it simply, your immune system isn’t functioning at 100% when your sleep is lacking. There are a few reasons for this. One has to do with a type of protein called cytokine, which kind of acts like the Paul Revere to your immune system, riding through your blood vessels and shouting “A virus is coming!” Cytokines are the messengers that get the word out when a virus is detected in your body, letting your immune system know when and where it should send its fighters. And when does your body ramp up its production of cytokines? That’s right: while you’re sleeping.

Your immune system’s brave virus-fighting warriors are also given a leg up by a healthy dose of sleep. In your body there’s a specific type of white blood cell that’s engineered for combating invading viruses, and it does so by sticking to the virus and destroying it. Studies have shown that these cells have an increased “stickiness” while you’re sleeping versus when you’re awake. You can imagine the difference as sleep giving these cells an actual battlefield to fight on, rather than a slippery ice rink.

Sleep vs. COVID-19?

Now after learning all this, you may be wondering: if our immune system can do so much to protect us, why has it been so weak against the coronavirus? 

The reason for the rapid spread and serious consequences of the coronavirus lies in the fact that it is what is called a novel virus, meaning that the human immune system has not learned yet how to protect itself from this particular virus. This is different from the common cold, for example, as human bodies long ago learned how to successfully fight that virus off, and then went on to carry that information in our DNA down through the generations. Coronavirus, on the other hand, is an entirely new beast, and it will take our immune systems time (and the help of vaccines) to learn how to beat this one.

Where your immune system does help against coronavirus—if by chance you do contract it—is helping to lower the severity of its attack on your body. While it hasn’t yet learned how to defeat it completely, your immune system is still capable of adapting to an invasion and performing its protective duties. But of course, the best protection is prevention—taking the proper precautions to avoid contracting COVID-19 in the first place.

Light at the end of the tunnel

While enduring this pandemic has been extremely difficult for all of us, bringing with it countless changes to our lives, we urge you to continue keeping up your body’s defenses by making a conscious effort to get a good night’s sleep. Sleep has always been an essential component of our health and wellbeing, but it takes on even greater importance in winters like these.