Since the COVID-19 pandemic, it has become clearer than ever: sleep is not a luxury, it is a necessity.

Sleep scientist Heidi Lammers – van der Holst cites three reasons why a good night’s sleep is so important.

1. Sleep protects
‘It has been known already for some time: you strengthen your immune system by sleeping well and you are less likely to be infected by a virus. When you are sleeping, you produce more white blood cells and these cells produce cytokines, the messengers of your immune system. And, as a study conducted in 2015 shows, this protects against, for example, viral infections. In this study, 153 people were infected in a laboratory with the rhinovirus, a common viral infection. These people had monitored how well they slept during the 14 days prior to being infected. And indeed, it turned out that lack of sleep increased the likelihood of catching a cold. People who slept less than seven hours, even had a nearly three times higher probability to come down with a cold than people who slept at least eight hours. A larger-scale study in 2016 confirmed these findings. Over 22,000 people, whose sleeping habits were known, indicated whether they had suffered a respiratory infection in the past month. Here again, the conclusion was that those who slept well (at least 7-8 hours) were sick less often. So, does a good night’s sleep also protect against COVID-19? It looks that way. Recent studies show that healthcare workers, who sleep long enough, are less likely to contract a COVID-19 infection. However, there are still many unanswered questions. We are awaiting the results of additional studies, so that we can find out more about the relationship between sleep and the risk of contracting COVID-19.’

Also read: How do I know whether I sleep healthily?

2. Caught a cold nevertheless? Sleep helps you recover
‘A good night’s sleep not only protects you, but if you do catch a cold nevertheless, sleep will help you to recover faster and better. This is also apparent from a study in 2020 of 164 people who were hospitalised after contracting COVID-19. They were asked to fill in a telephone questionnaire about their lifestyle in the week before they fell ill. A control group of 228 non-patients were also asked to fill in the questionnaire. The shorter people slept before they contracted COVID-19, the greater the likelihood of severe symptoms and a longer hospital stay. That there is also a correlation between sleeping badly and an ICU stay due to a COVID-19 infection is also apparent from another very recent study.
Sleeping is not only essential to repair the damage caused by viruses, but it also helps your body repair wounds. This is apparent from a study in 2018, in which researchers inflicted (painless) small blisters on the skin of test persons. They were then divided into two groups. One group slept normally; the other group was only allowed to sleep no more than two hours a night for four days. This lack of sleep had a considerable effect on how fast the wounds healed. The wounds of the persons who slept well healed in four days; the wounds of the night owls took a day longer to heal. In short, sleeping is essential for the self-healing ability of your body.’

3. Sleep gives your immune system a bonus boost
‘Sleep strengthens your immune system directly and indirectly. Sleeping well helps, for example, to maintain a healthy blood sugar level and a healthy weight, which in turn are important for a strong immune system. Moreover, as a result of a lack of sleep you are more likely to become overweight and have too high blood sugar levels, and that increases the risk of all sorts of diseases, for instance, obesity, diabetes and sleep apnea, a disorder that makes sleeping even more difficult. It is exactly the people who suffer from these disorders who appear to have a higher likelihood of contracting a virus infection such as COVID-19 and becoming seriously ill from this. Fortunately, the opposite also applies, and you can prevent this downward spiral from occurring by sleeping well. In this manner, you can give your immune system an extra positive boost!