Current science notes important connections between sleep quality, the circadian rhythm and COVID-19 and other health threats. These links relate to the impact of sleep quality on circadian rhythm health and optimal immune system functioning, as well as to the influence of circadian rhythms on how the immune system physically functions.

In terms of COVID-19, researchers point to the many ways this pandemic has been disruptive to sleep quality and the importance of taking an active role in improving sleep quality as a means of protecting health and reducing COVID-19 risks.

Circadian Rhythm and COVID-19 Risk

In light of the deepening understanding of how immune system function is influenced by circadian rhythms and body clocks, researchers have been taking a sharp look at the impact of the widespread pandemic lockdowns on potential COVID-19 risks related to immune function.

Studies indicate that the lockdowns and the stress of the pandemic have contributed to an increase in both circadian rhythm disruption and sleep disturbances. Because those two factors – disrupted sleep and disrupted circadian rhythms – are typical of those engaged in shift work and overnight work, it makes this an ideal group to research for the potential for increased COVID-19 risk.

Studies have already shown that shift workers, especially those working the overnight shift, are more likely to suffer from upper respiratory infections, such as cold and flu viruses, than are their day shift counterparts. A Japanese study of emergency room doctors – combining high stress conditions with shift work – found overnight and rotating shift work schedules were linked to measurable immune system function changes. These changes included a reduction in innate immune response; specifically a decrease in the activity of the immune system’s natural killer cells. Furthermore, that decrease in activity was directly linked to a lack of sleep and poor sleep quality.

Poor quality sleep is also directly related to circadian rhythm disruption. Circadian rhythms directly impact immune system function on a mechanical level. One of the primary ways that circadian rhythms impact immune function has to do with the timing and coordination of immune responses, such as body temperature and inflammatory responses. Indeed, the influence of circadian rhythms reaches down to the timing of the activities of individual cells, controlling essential processes, including energy production and waste removal.

Chronic circadian rhythm disruption has been repeatedly linked to an increase of risk for many diseases, including cardiovascular diseases, metabolic disorders, diabetes and some cancers. Circadian rhythms play a vital role in immune system functioning. Thus, it is reasonable for researchers to conclude that chronic and ongoing circadian rhythm disruption can increase the risk of developing COVID-19 and may make it more difficult for the immune system to battle the virus.

Where Sleep Quality Comes In

As noted by researchers, sleep disturbances have increased during the pandemic and its related social distancing, quarantines and lock downs. The stress of separation from family and friends, worries about health, financial concerns and the major disruptions to daily schedules many experienced, such as unemployment, working from home and virtual schooling for children, have contributed to disrupted sleep.

While disrupted sleep, insufficient sleep and overall poor quality of sleep are never good for health, it may be particularly troublesome during such a major health event as a pandemic. That is because sleep quality has a direct impact on the ability of the immune system to function at optimal levels. Insufficient sleep has even been shown to impact how effective certain vaccines are. According to the Centers for Disease Control and Prevention (CDC), not getting enough sleep decreases antibody production after a flu vaccination by more than 50 percent.

During sleep, important immune system processes take place, including improving immune cell memory. This memory improvement takes place during deep sleep and helps better equip the immune system to fight against both pathogens it has already encountered and those that are similar to previously dealt with pathogens. Another way sleep impacts the mechanical operations of the immune system is through its key role in hormone regulation, allowing T cells to become stickier and better able to fight viruses.

Disruption Matters: Reduce and Realign for Better Health

When it comes to protecting yourself from COVID-19 and protecting your overall health and well-being, disruption matters. Disrupted sleep and the disruption of daily activities, such as work, physical activity and meal times, are strong contributors to circadian rhythm disruptions, all of which have a proven negative impact on immune function.

Work towards optimal immune system function and better health by reducing sleep disruptions and improving sleep quality to help realign your circadian rhythm. Part of that is maintaining a healthful daily rhythm that includes scheduled sleep, wake and meal times, regular physical activity, increased morning light exposure and decreased evening artificial light exposure.