The Influence of Sleep on a Functional Immune System

In an interview with Dr. Verena Senn, Neurobiologist and Sleep Expert at Emma – The Sleep Company

Frankfurt, March 23, 2020. Whenever a flu wave is just around the corner, health tips start piling up. The given advice to sleep a lot is a popular and extremely effective option. However, Sars-CoV-2 (“Corona virus”) is not a flu–pathogen, but a different Virus strain. How sleep helps the immune system ward off viruses or mitigate their effects is exposed in detail by Dr. Verena Senn, a Neurobiologist and Sleep Expert at Emma – The Sleep Company.

Why is sleep so important for a well-functioning immune system? What role does the immune system play in health?

Dr. Verena Senn: Luckily, the trend of depriving yourself of sleep to obtain success is ebbing away. Instead, sleep has become a trending status symbol: the more you get from it, the better. This is a very important development, because a sufficient night’s sleep also strengthens our immune system. A well-functioning immune system is the backbone of our health, it is essential in our defense against viruses, as many independent studies worldwide communicate.

Viruses infect our cells by docking to surface proteins and injecting their own matter into our cells. As a result, our own cell’s production is hijacked and starts to produce more and more viruses. When this process is complete, the infected cell dies and releases these new viruses, which then infect other cells again. However, we are regularly exposed to a variety of viruses and our immune system always has its own protective functions in place. Prominent members of our internal defenses are the so-called natural killer cells – a type of white blood cells. They detect the infected cells and can silence their activity or remove them early before the new viruses are reproduced.

In order to have enough natural killer cells in the body, sleep is of utmost importance. If we regularly sleep too little, we are much more susceptible to illnesses and infections. Researchers have studied how the number of white blood cells (natural killer cells) develops under sleep deprivation. Result: test groups that slept only four hours instead of eight, experienced a decrease in the proportion of their natural killer cells by 70 percent. This is a striking finding and a clearly appeal to always ensure enough sleep. You might remember this the next time you stream a series.

How many hours should someone sleep per night and when should one goes to bed?

Dr. Verena Senn: The World Health Organization (WHO) recommends 7-9 hours of sleep per night. Contrary to popular belief, you cannot compensate for lost sleep, but for only in a very minimal and limited fashion. There is no uniform or optimal time to go to bed. But there is the inner biological clock – called by chrono biologists – the circadian rhythm. Throughout the day-night cycle of the Earth, this inner clock is synchronized again and again. However, the synchronization of our inner clocks is very individual, which accounts for why there are early risers and people who prefer getting up late.

In addition to the circadian rhythm, biochemicals affect when we get tired. In the cerebrospinal fluid, these biochemicals build up in the body during the day and increase our desire for sleep. Inversely, while we sleep these substances are broken down. One of the most important biochemicals is adenosine. Adenosine inhibits the ‘active areas’ in the brain and makes us feel tired (see chart below). Antagonistically, Caffeine acts as a detractor to adenosine. And since caffeine has an active period of 6-8 hours before it is completely degraded: one should avoid drinking coffee in the late afternoon!

What else can be done to promote good sleep?

Dr. Verena Senn: First of all, I would like to point out the inner clock and its link to light and dark. The inner clock is largely controlled by the hormone melatonin. Receptors in our eyes are sensitive to blue light and signal the brain that it is daytime – time to be alert and wake up. In order for our melatonin to maintain a healthy sleep/wake cycle, smartphones or laptops, for example, should be used only to a very limited extent of one to two hours before bedtime. By the way, this has another reason: Studies prove that online activities like the care of social contacts or the retrieval of current news can prevent us from coming down to rest and fall asleep.

I also recommend sleeping at a room temperature of about 19°C and drinking more water during the day than in the evening. Cuddling up to something warm or taking a bath can also improve how quickly and easily we fall asleep. The heat dilates the blood vessels in the hands and feet. Sounds paradoxical, but this sets free excess body heat – that’s exactly what the body needs to fall asleep and sleep through.

For current reasons: What should home office newcomers pay attention to regarding the topic of sleep?

Dr. Verena Senn: People who are setting up their home office should ideally choose a place outside the bedroom or at least a separate corner to work. We recommend compartmentalizing areas for our daily routine, such as for work, and places for rest and regeneration. This also applies to time schedules – although you may be at home all day, you should separate the working hours from breaks and consciously end the working period in the evening.Page Break

Infobox – did you know?

The role of adenosine in the search for a Covid-19 vaccine

A vaccine against Covid-19 has not yet been developed. Currently, some pharmaceuticals for the treatment of Covid-19 are being tested that are already used against other viruses, such as HIV or Ebola. One of these pharmaceuticals (Remdesivir) mimic the body’s adenosine. Remember: adenosine is the substance in the brain that (amongst others) is responsible for us getting tired.

But adenosine has several functions in the body. It is also required by some viruses to multiply, such as the corona viruses. Viruses always infect the body’s own cells and then use them to multiply themselves. In doing so, they bring their own genetic material with them and ultimately destroy their host cells. However, if the adenosine analogue provided by the drug is incorporated into the genetic molecules of the new Corona viruses, this stops or slows down the production of new viruses. Result: the symptoms of the disease are stifled, and you get well again.

In first tests, this pharmaceutical showed promising results in the treatment of the novel corona virus. Several clinical trials are currently underway in China and a small number of Covid-19 patients already received the drug for testing purposes. In Germany, too, three clinics are involved in test studies.

Note: Wherever there is talk of Sars-CoV-2, we speak of the virus. For the disease we use the term Covid-19 (colloquially Corona).


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About Emma – The Sleep Company (Bettzeit GmbH):

Emma – The Sleep Company is an owner-managed company and one of the fastest growing providers of mattress and sleeping systems based in Frankfurt am Main. The internationally active sleep tech was founded in 2013 by Dr. Dennis Schmoltzi and Manuel Müller and turned over 150 million euros in 2019 (+86 percent). The portfolio includes the Direct-to-Consumer startup Emma Mattress, which quickly became one of the top 3 bed-in-a-box providers in Europe, as well as the strong traditional brand Dunlopillo. With their in-depth expertise in research and development, they constantly translate material and technological advances into their high-quality product range. In October 2019, the Emma One mattress (90x200cm, hard) became the new test winner of Stiftung Warentest (issue 10/2019) with a total score of 1.7 (good). In addition, the team of more than 300 people continuously implements innovative concepts in the areas of process optimization as well as marketing and sales. The success drivers of the very agile day-to-day life of the company are a strong digital mindset, the courage to pragmatic solutions and lived diversity.

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