How sleep affects the immune system

A tight connection between autoimmune conditions and sleep quality

Sleep is critical for maintaining a healthy body. Disturbed or too little sleep has an impact on the likelihood of developing a number of health conditions, as well as your ability to recover.

Sleep, brain, and the immune system

Approximately 1 in 4 people today experience some sort of sleep disturbance (1). This is a stunning number of people suffering from a lack of one of the body’s crucial functions.

Sleep helps the body redistribute energy resources that are primarily used for brain and muscle work to the immune system. During sleep, the immune cells get out of the circulation, settle in the lymph nodes and start getting ready for the next day of work (2, 3). A similar thing happens in the brain; it not only doesn’t recharge, it also cleans itself up from all the toxic waste of the day, which can otherwise cause inflammation (4).

During sleep cortisol and adrenaline levels drop, while melatonin rises. This helps to counteract inflammation by reducing some of the damaging molecules called reactive oxygen species (ROS) (2).

Sleep creates a unique constellation of immune system and hormones. These are helpful because the active immune system is energy-dependent, and changes in hormone levels during sleep enable our bodies to take extra energy from the muscles and utilize it for building up and maintaining a healthy immune system (4–6). Our hormones are so brilliant, that in the time we are about to wake up, they again rearrange our immune system in order to prepare it to start working from the moment we are up (7, 8).

Lastly, it is not only the brain that determines sleeping patterns. It goes the other way around, too, and the connecting part in this case is the immune system (9). There are two distinct groups of immune cells and molecules which either increase or decrease the amount of deep sleep experienced throughout the night (10–12).

How does poor sleep affect the immune system?

Poor sleep will over time lead to increased inflammation in the body (13, 14), because lack of sleep causes a drop in the production of molecules that counter inflammation (15, 16).

A lack of sleep also makes you vulnerable to viruses and bacteria (17), meaning you might be more prone to catch a cold or flu when you’re sleep deprived (18).

Even if you are only slightly sleep deprived, your body is likely to activate certain parts of the immune system responsible for autoimmune flare-ups (19). This effect is especially strong in women (20, 21).

Sleep is affected by many more biological factors, such as age or the level of physical activity.

A lack of sleep not only causes the immune system to go awry and makes you more susceptible to viral and bacterial infections, it also leads to the breakdown of immune self tolerance (tolerance of our immune system to our own body) which triggers autoimmune diseases (22).

How does inflammation affect sleep?

When talking about autoimmune flare-ups, scientifically we are talking about inflammation happening in the body. Inflammation changes how the brain processes signals, as well as how the brain regulates sleep (23). In the case of ongoing, persistent and chronic inflammation, the body requires much more energy, meaning you have to sleep longer to get enough energy (24).

If an increased amount of certain antibodies are present in the body, you will have more problems sleeping. Some researchers even want to classify narcolepsy as an autoimmune condition (25).

Age as a factor in the sleep-immune system interaction

Age changes how you sleep. Conversely, this means your immune system will change, too. As you approach your 50s, your sleeping patterns will have notably started to change: you will go to bed earlier, take a longer time to fall asleep, sleep for shorter periods of time, and probably wake up several times a night (26).

What can fix the inflammation-sleep loop?

Inflammation can be reduced and sleeping patterns can be improved by practicing mindfulness-based meditation, or through cognitive behavioral therapy (27, 28).

What are the symptoms to look out for?

Sleep deprivation may cause the following:

  1. Daytime sleepiness
  2. Cognitive impairment
  3. Reduced effectiveness of vaccination (you might notice it with flu vaccinations) (29)
  4. Increased obesity and increased appetite (this happens because levels of the anti-hunger hormone leptin are low and levels of the hunger hormone gherlin are increased as a consequence of disturbed and short sleep) (30–32)
  5. Heart problems, including high blood pressure and high risk of heart attack (33–35)

Track your sleep and other symptoms with the Boost Thyroid app to understand how to improve your health.

References

  1. LeBlanc M, et al. Incidence and risk factors of insomnia in a population-based sample, 2009
  2. Besedovsky L, et al. Sleep and immune function, 2012
  3. Motivala S, et al. Sleep and immunity: cytokine pathways linking sleep and health outcomes, 2007
  4. Lange T, et al. Effects of sleep and circadian rhythm on the human immune system, 2010
  5. Haus E. Chronobiology in the endocrine system, 2007
  6. Straub RH, et al. Energy regulation and neuroendocrine–immune control in chronic inflammatory diseases, 2010
  7. Dodt C, et al. Plasma epinephrine and norepinephrine concentrations of healthy humans associated with nighttime sleep and morning arousal, 1997
  8. Elenkov IJ, et al. Low- versus high-baseline epinephrine output shapes opposite innate cytokine profiles: presence of Lewis- and Fischer-like neurohormonal immune phenotypes in humans? 2008
  9. Irwin MR, et al. Reciprocal regulation of the neural and innate immune systems, 2011
  10. Imeri L, et al. How (and why) the immune system makes us sleep, 2009
  11. Spath-Schwalbe E, et al. Interferon-α acutely impairs sleep in healthy humans, 2000
  12. Lorton D, et al. Bidirectional communication between the brain and the immune system: implications for physiological sleep and disorders with disrupted sleep, 2006
  13. Shearer WT, et al. Soluble TNF-alpha receptor 1 and IL-6 plasma levels in humans subjected to the sleep deprivation model of spaceflight, 2001
  14. Vgontzas AN, et al. Adverse effects of modest sleep restriction on sleepiness, performance, and inflammatory cytokines, 2004
  15. Spiegel K, et al. Impact of sleep debt on metabolic and endocrine function. Lancet, 1999
  16. Spiegel K, et al. Leptin levels are dependent on sleep duration: relationships with sympathovagal balance, carbohydrate regulation, cortisol, and thyrotropin, 2004
  17. Vgontzas AN, et al. Insomnia with objective short sleep duration: the most biologically severe phenotype of the disorder, 2013
  18. Cohen S, et al. Sleep habits and susceptibility to the common cold, 2009
  19. Meier-Ewert HK, et al. Effect of sleep loss on C-reactive protein, an inflammatory marker of cardiovascular risk, 2004
  20. Irwin MR, et al. Sleep loss activates cellular inflammatory signaling. Bill Psychiatry, 2008
  21. Suarez EC. Self-reported symptoms of sleep disturbance and inflammation, coagulation, insulin resistance and psychosocial distress: evidence for gender disparity, 2008
  22. Palma BD, et al. Effects of sleep deprivation on the development of autoimmune disease in an experimental model of systemic lupus erythematous, 2006
  23. Dantzer RO, et al. From inflammation to sickness and depression: when the immune system subjugates the brain, 2008
  24. Bryant PA, et al. Sick and tired: does sleep have a vital role in the immune system? 2004
  25. Silber MH. Autoimmune sleep disorders, 2016
  26. Mander BA, et al. Sleep and Human Aging, 2018
  27. Creswell JD, et al. Mindfulness-based stress reduction training reduces loneliness and pro-inflammatory gene expression in older adults: a small randomized controlled trial, 2012
  28. Irwin MR, et al. Cognitive behavioral therapy versus tai chi for late life insomnia and inflammation: a randomized controlled comparative efficacy trial, 2014
  29. Spiegel K, et al. Effect of sleep deprivation on response to immunisation, 2002
  30. Taheri S, et al. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index, 2004
  31. Simon C, et al. Circadian and ultradian variations of leptin in normal man under continuous enteral nutrition: relationship to sleep and body temperature, 1998
  32. Herculano-Houzel S. Sleep It Out, 2013
  33. Ayas NT, et al. A prospective study of sleep duration and coronary heart disease in women, 2003
  34. Grandner MA, et al. Short sleep duration and insomnia associated with hypertension incidence, 2013
  35. Heslop P, et al. Sleep duration and mortality: the effect of short or long sleep duration on cardiovascular and all-cause mortality in working men and women, 2002
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