Sleep & the Immune System

By Melissa Blake, ND

When it comes to building a healthy immune system, we often hear about diet and exercise, but unfortunately less often about the importance of sleep. But, when it comes to the immune system, sleep is a crucial component. Researchers around the world continue to discover the numerous benefits of our nightly slumber.

Sleep is when the body and the mind have a chance to rest and repair on a cellular level, and without enough of it, or enough quality sleep, one’s health can begin to suffer.1 Disrupted sleep is a major contributor to hormone imbalances, skin issues, weight gain, and even a weakened immune system.1-4

Whether you’re not sleeping well due to stress, your schedule, or another factor, prioritizing sleep is a key component to a healthy immune system.1

The sleep debt cost

Most likely everyone can relate to the immediate impact of a sleepless night. Even getting just a little less sleep than one needs or is used to can contribute to confusion, weakness, muscle pain, and changes in appetite.2-4

The long-term consequences of neglecting sleep are even more serious. A regular lack of sleep increases the risk of cardiovascular issues, weight gain, and compromised immune function.4,5

Correlation between sleep & immune health

Driven by a circadian rhythm, messengers called cytokines impact the state of the immune system and also contribute to sleep-wake patterns.1  While we are sleeping, cytokines instruct immune cells to work hard at repairing damage, clearing toxins, and defending us against illness.1 This might be one reason why we feel more tired and require more rest when we are sick. It’s during sleep that the immune system is most active and focused on recovery and developing immune memory.1

A good night’s rest is also key for improving the function of immune cells known as T cells, a type of immune cell that fights against pathogens such as viruses.6 A German study found that in people who slept adequately the night before, T cells were better able to attach to their targets, including virus-infected cells, than in the T cells of those who stayed up all night.7 The findings highlight one of many immune-supportive effects of sleep.


Habits such as a consistent routine, including regular bed and wake times, as well as exposure to natural sunlight within an hour of waking are small, simple changes people can make in order to get a better night’s sleep while improving their body’s circadian health. Even going to bed just 10 minutes earlier can have a profound effect on how you feel, so give it a try starting tonight—your immune system will thank you.

This is the first in a three-part series on circadian health. For more information on sleep and other general wellness topics, please visit the Metagenics blog.


  1. Besedovsky L et al. Physiol Rev. 2019;99(3):1325-1380.
  2. Bolin DJ. Curr Sports Med Rep. 2019;18(8):305-310.
  3. Spaeth AM et al. Sleep. 2013;36(7):981-990.
  4. Patel SR et al. Am J Epidemiol. 2006;164(10):947-954.
  5. CDC. How does sleep affect your heart health? Accessed April 23, 2021.
  6. Besedovsky L et al. Pflugers Arch. 2012;463(1):121-37.
  7. Dimitrov S et al. J Exp Med. 2019;216(3):517-526.
Melissa Blake, ND
Melissa Blake, ND is the Manager of Curriculum Development at Metagenics. Dr. Blake completed her pre-medical studies at Dalhousie University in Halifax, Nova Scotia, and obtained her naturopathic medical training from the Canadian College of Naturopathic Medicine. Dr. Blake has over 10 years of clinical experience, specializing in the integrative and functional management of chronic health issues.

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