Now that many communities are slowly reopening their doors as we learn to live in this new normal, which includes thorough hand washing and keeping a two-metre (six-feet) distance, it is increasingly important that we take precautionary steps to strengthen our body’s ability to fight infections. That’s what our immune system is for: you can think of it as your body’s defence against intruders. This system is comprised of different types of white blood cells (e.g. lymphocytes & neutrophils) which attack unwelcome pathogens.
Different things can affect our immune system’s ability to perform its protective duties, such as our stress levels, our daily exercise, and of course our sleep schedule. Many studies have explored the bidirectional relationship between sleep and the immune system from which we inspired the following tips:
Sleep 7-8 Hours Each Night
For many years now the relationship between length of sleep and immune health has been known. Though it is important to keep in mind that COVID-19 is so new that studies on this specific disease are still underway and changing rapidly, we can acknowledge studies relating sleep to other respiratory diseases and err on the side of caution by getting the recommended amount of sleep. Some studies on humans involving self reports found that those who usually slept fewer or equal to 5 hours/night were more at risk of getting pneumonia in the following two years, and they also had higher reports of respiratory infections in the past month compared to those sleeping 7-8 hours per night. Obviously there are some exceptions to the rule who need less sleep than others (See Sleep Chronotypes). Other studies found that sleeping more than 9 hours/night also posed increased risk. (1)
This is super interesting: self-reports on napping show a boost in immune-related cells. With this said, it is important to keep in mind that research in this field is still sparse and results are mixed and largely affected by factors like duration and time of nap. Laboratory studies (those where environmental factors are controlled and measured) have shown that a nap lasting 2 hours in the mid-afternoon can counteract some of the negative effects of missing a night of sleep. (2)
Don’t Disrupt Your Circadian Rhythm
Now this tip obviously won’t be useful for those working in essential services or other jobs requiring shift work, but for the rest of us it can be really useful. It’s so easy to decide to stay up later than usual to continue binging Netflix. Well, research suggests that respecting your circadian rhythm (e.g. getting up with the sun and going to sleep with the sun) is really important for immune system health. One study looking at shift workers found that this group has an increased risk of getting a viral infection. Those working night shifts are more susceptible to upper respiratory infections like flus and colds. They suspect that this is because of sleep loss due to disruptions of the circadian rhythm, causing inadequate immune response. In China, one recent study looking at those affected by COVID-19 revealed a pattern of chronic illness and also of poor sleep quality. Keep in mind that this is a correlational study, so it doesn’t confirm cause and effect. More research still needs to be done on this topic. (3)
There are many tips and tricks out there that can help us improve our sleep health, such as these 10 tips for a better sleep by Dr. Joti Samra, R.Psych. If you find that you’ve searched the great depths of the Internet and tried every suggestion out there but somehow you can’t stop ruminating, tossing and turning in bed, Cognitive Behavioral Therapy (CBT) may be a good option for you. Talking to a trained psychologist about your sleep challenges and addressing the root causes via CBT can yield great results. In fact, it was found that CBT outperforms insomnia medication both short term and long-term. (4)
Though we may still be learning about COVID-19 and information is evolving rapidly, one thing is certain: sleep and the immune system have a bidirectional relationship (they affect one another). There is some power in knowing that improving our sleep health using the four tips above can work to strengthen our immune system and ability to fight off any intruders that visit our bodies. In addition to following all the safety measures put in place by officials on hand-washing and social distancing, let’s get some sleep!
(1) (2) (4) Besedovsky, L., Lange, T., & Haack, M. (2019). The sleep-immune crosstalk in health and disease. Physiological Reviews, 99(3), 1325-1380. doi:10.1152/physrev.00010.2018
(3) Silva, F. R. d., Guerreiro, R. d. C., Andrade, H. d. A., Stieler, E., Silva, A., & de Mello, M. T. (2020). Does the compromised sleep and circadian disruption of night and shiftworkers make them highly vulnerable to 2019 coronavirus disease (COVID-19)? Chronobiology International, , 1-11. doi:10.1080/07420528.2020.1756841