The impact that sleep has on our health and overall physiology appears to have no bounds. Research has shown this time and time again, so it is no wonder that sleep plays a role in immune functioning – something which is of particular interest now, as the world faces a COVID-19 pandemic. 

People worldwide have been left wondering what they can do to best support their immune system, protect the people around them and, ultimately, prevent the risk of contracting the COVID-19 virus themselves.

Sleep is one of the most crucial pillars in supporting our body’s defence systems. A landmark study by Cohen and colleagues (2009) showed this clearly. Participants that had slept less than seven hours per night were revealed to be three times more likely to develop symptoms after a direct application of cold virus, compared to those that slept eight hours or more. A more recent study from the same research group (Prather et al., 2015), reported similar results – showing a significant increase in risk of developing cold symptoms for individuals sleeping less than six hours compared to those that had slept for seven hours or more. 

How can I sleep better? 

1. Building a better bedtime routine

Establish a bedtime routine that you can consistently follow each night, that reliably leads to sleep. Sleep is all about rhythm and routine, so as soon as you can find a consistent schedule to relax and achieve sleep, this is a key component in building a better sleep regime.

There are lots of options in sleep routine building. What works for you may not work for someone else, but popular solutions tend to include:

  • Taking a hot bath
  • Meditation
  • Stretching
  • Reading a printed fiction book
  • Listening to music
  • Spending time with family

What is important in making a routine stick is consistency. As soon as you find something that works, whatever it may be for you, the more consistently you adhere to it, the more the benefits of it will continue to increase over time.

2. Getting more exposure to natural light

More contact with natural light is directly linked to an improved ability to sleep at night time. Studies have shown that the more natural light we are exposed to before noon, the more readily we will sleep when it gets dark.

When it comes to increasing your exposure to natural light, our recommendations are as follows:

  • Get between 30-90 minutes of natural sunlight before noon each day
  • Don’t be put off by cloud cover – the effects of daylight still apply when it is gotten through clouds 
  • If you can’t get outside in sunlight before noon, consider buying a daylight lamp – desk lamps that mimic the intensity of sunlight, and deliver similar effects to natural sunlight
  • Use a daylight lamp for 30-90 minutes a day within 1-2 feet of your face

Whether you increase your exposure to light with natural sunlight or a daylight lamp, you should see a noticeable improvement in the quality and length of your sleep day to day.

3. Trying a supplement plan

Our trainers have assembled a comprehensive daily plan of sleep supplements that, when combined, will give you the best possible chance of having a good night’s sleep. We have used some of our own products as reference points here, although many brands will offer similar supplements – pay close attention to the main active ingredient and match up accordingly.

4. Trying sleep hygiene products

We can also recommend several sleep hygiene aids to wear or use in your bedroom. Our recommendations help to cover several essential aspects of sleep hygiene, from adequate daylight exposure to blocking blue light in the evenings, and even bathing your bedroom in white noise to block out persistent, disturbing noises in the lead up to sleep.

  • Lumie Vitamin L Daylight Lamp – use for 30-90 minutes a day, ideally between 12pm and 1pm to give you plenty of exposure to daylight, even in dim, artificially-lit office environments
  • Lumie Daylight Alarm Clock – use in place of your phone or traditional alarm clock, this wakes you up with a gradual artificial sunrise that wakes you up more naturally, and less abruptly
  • Sleep Master Sleep Mask – use the mask if your bedroom isn’t pitch black at night, and the accompanying ear plugs if you are easily disturbed by noise
  • THL Sleep Blue Light Blocking Glasses – wear these for 1-2 hours before you intend to get into bed, as they block out the blue light in modern screens known to disrupt our circadian rhythm
  • ANTEK Sleep White Noise Machine – for anyone that would rather not use ear plugs, and block out only persistent low level noises – not more important noises like the cries of a newborn baby

Why does sleep help the immune system? 

Though the relationship between sleep and our immune system is complicated, scientists have suggested that sleep plays a key role in the production and release of pro-inflammatory cytokines – proteins released from immune cells that initiate immune responses when presented with potentially dangerous pathogens.

Further, we see a significant boost to systems supporting growth and restoration during sleep – one of many reasons why sleep is so important in early life. At the same time, in sleep we see a slowing of ‘stress systems’ in the body – which is advantageous because, typically, these systems suppress the functioning of the immune system while mobilising us and preparing us for action. In a rest state, none of this is needed.

Sleep plays a crucial role in improving both our innate immune response, and our adaptive immune response. The innate immune response prevents the spread and movement of foreign pathogens throughout the body, while preparing to mount an attack on foreign pathogens. The adaptive immune response is only activated when our innate response is insufficient to control the foreign pathogen that has entered the body. It is also critical in creating immunity against specific pathogens. The adaptive immune response specifically is believed to be the reason that vaccinations are as effective as they are in preventing future illness – responsible as it is for immunological memory, wherein our bodies reflect on past infections, learn from them, and produce a more effective immune response when the pathogen next enters the body.

This means that, in a way, being well-slept makes vaccines work more effectively than they would if we were poorly slept. In one study, subjects who slept the night before receiving the hepatitis A vaccination displayed a twofold increase in antigen specific antibodies (commonly used as a measure of the adaptive immune response) compared to those that hadn’t slept (Benedict et al., 2012; Prather et al., 2012). The effects observed here have even been shown to last for up to a year after receiving the initial vaccination.

The effects of sleep on immunity are anything but short-term benefits, therefore. We have now seen that a good night’s sleep can significantly influence your long-term ability to fight off disease

In fact, although chronic sleep loss over days and weeks has been linked with increased levels of pro-inflammatory cytokines, this increase does not result in improved immune functioning. Instead, researchers refer to continued sleep loss as an “unspecific state of chronic stress” – akin to low-grade systemic inflammation, known to increase risk of type II diabetes, cardiovascular disease and more. Inflammation of this kind can also lead to immunodeficiency, which is associated with an enhanced susceptibility to infections and illness, as well as a reduced immune response to pathogens and vaccinations.

Getting at least eight hours of sleep a night should be one of your first ports of call in defending yourself against COVID-19. Sleep should be as high on your priority list as any other measures you introduce to your daily lives to help fight off COVID-19.

Key points

  • Sleep is a crucial pillar for health, equal in importance to diet, physical fitness, sunlight exposure and other factors.
  • Adequate sleep makes you less susceptible to illness, more capable of effective recovery from illness when it strikes, and better adapted to illness for the foreseeable future, as well as now.
  • The main effects of sleep on immunity are increased production, release and effectiveness of pro-inflammatory cytokines associated with more robust immune response.
  • Adequate sleep increases the immune response to vaccinations, both in the long and short term.
  • Individuals of all ages are impacted by sleep loss. It is not just adults and the elderly that are negatively impacted by poor sleep.