Rest and Resist: Sleep for Your Immune System

How to reduce Covid, colds and flu by boosting your immune health

Have you or someone you know had COVID recently? It is likely that their sleep was impacted. Conversely, when you aren't sleeping well, it increases the risk of COVID and other respiratory infections. The sleep difficulties of acute COVID infection are due to other symptoms: a fever, a cough, a sore throat, headache, and muscle aches. These all make sleeping more difficult.

Sleep in Long Covid
There's also the issue of long COVID or post-COVID congestion (PCC), which you have probably heard about. Studies find 41% of people who have long COVID experience moderate to severe sleep problems. That's a significant number. Long COVID is generally defined as symptoms that persist for weeks or longer after the initial COVID infection. Some factors that seem to increase the risk of sleep problems associated with long COVID include: hospitalization due to COVID, being of Black race, having severe anxiety, and moderate to severe fatigue. One reason we think people with long COVID develop insomnia is due to the associated mental health problems, such as severe anxiety. Deep sleep is often decreased in those with long COVID, contributing to a less restful experience. The chronic pain or shortness of breath that's associated with long COVID can also increase insomnia. Lastly, there seems to be a bit of a circadian shift, with people experiencing a delayed sleep-wake phase.

What’s the connection between immune function and sleep?
Sleep and the immune system support each other. During sleep, some of our physiological functions decrease. Our heart and respiratory rates decrease, particularly in deep sleep, which allows more energy to be directed towards immune function. Cytokines, which fight infection, are more active during deep sleep than at any other time of day. If you have sleep problems, you're more susceptible to getting infections. People who sleep less than six or seven hours tend to have increased infections. Over the course of the night, inflammation typically decreases, but with sleep deprivation, we don't get the anti-inflammatory effects of sleep, nor of the high melatonin levels.

During infections there’s also a change in REM sleep. During REM sleep, our skeletal muscles are paralyzed, which prevents shivering. Fever helps fight infections, as infectious agents struggle to survive in higher body temperatures. We tend to have less REM sleep during an infection because shivering is necessary to maintain a fever, and we can't shiver during REM.

Sleep status impacts vaccines
For those who take vaccines, research shows that getting optimal sleep before getting vaccinated makes the vaccine more effective. If you're sleep-deprived when you get a vaccine, it won't be as effective.

Sleep Skills
Let’s shape our sleep to prevent viral infections, and reduce their impact if we do get sick.
1.     Continue to get optimal sleep time night after night, build that time into your lifestyle routine.
2.     Establish a robust circadian rhythm with bright outside light exposure in the morning and throughout the day, and darkness at night for optimal melatonin production.
3.     If you do get sick, take the time you need to sleep.
4.     Eliminate sleep disruptors during that time, such as alcohol and caffeine.
5.     When you aren’t sleeping, rest in another room, so your bed is only associated with sleep.

Sleep well and Dream big,
Dr. Catherine

PS. We talked about Blue Blocking Glasses last week, then Nikko Kennedy of Brighter Days Darker Nights wrote on additional strategies you may find interesting.

Women’s Sleep Course Become a Skilled Sleeper
Quick Daily Sleep Skills Dr. Catherine Darley | Natural Sleep Expert (@skilledsleeper) • Instagram photos and videos

Select References:
1.     Shafiee A, Jafarabady K, Rajai S, Mohammadi I, Mozhgani SH. Sleep disturbance increases the risk of severity and acquisition of COVID-19: a systematic review and meta-analysis. Eur J Med Res. 2023 Oct 18;28(1):442.
2.     Su, Y., et al. (2022). Multiple early factors anticipate post-acute COVID-19 sequelae. Cell, 185(5), 881–895.e20
3.     Larenas-Linnemann D, et al. Enhancing innate immunity against virus in times of COVID-19: Trying to untangle facts from fictions. World Allergy Organ J. 2020 Nov;13(11):100476.
4.     Zimmermann P, Curtis N. Factors That Influence the Immune Response to Vaccination. Clin Microbiol Rev. 2019 Mar 13;32(2):e00084-18.

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