We hear it over and over again – poor sleep makes you sick. And it’s true; lack of restful sleep hurts not only your mental memory but also your immunological memory.
If you chronically sleep less than five hours, your risk of succumbing to a flu virus is 45 percent. If you sleep five to six hours, it’s 30 percent; if you sleep six to seven hours, it’s only 25 percent. And if you sleep more than seven hours, it’s less than 20 percent.
But that’s not all! Since sleep is so crucial for your immunological memory, it also profoundly impacts your response to vaccination. In other words, if you don’t get enough restful sleep before and after vaccination, you produce much less immune reaction. This has been proven in tests for the standard flu as well as hepatitis A and B vaccine but might also be crucial for the efficacy of the current Covid vaccine.
Why sleep promotes your immunological memory
Immunological memory is the ability of the immune system to recognize an antigen that your body has previously encountered quickly and initiate an appropriate immune response. But how does this process work?
Keep in mind that tens of trillions of T cells are responsible for immune information in your body. These T cells are not nerve cells but white blood cells produced in the bone marrow and mature in the thymus, which is why they’re called T cells.
The thymus, in turn, is a small organ of the lymphatic system located behind the sternum and between your lungs that is only active until puberty. After puberty, the thymus starts to slowly shrink and become replaced by fat.
Because of these limited resources, information is transformed into core information for both immune system memory and our mental memory. In simple terms, the data gets abstracted to save space or to be able to store as much as possible.
And this is where sleep comes in: sleep helps with this necessary abstraction through the flow of information from the hippocampus to the neocortex and corresponding encoding processes.
Why sleep has a significant influence on the course of a disease
While you’re asleep, the number of cells that capture the pathogen – such as a flu virus – increases and presents it to the immune system’s killer cells. The increased T-cells are responsible for the defense mechanism and migrate from the blood to the lymphatic tissue. This is why you can recognize an inflammation by the swollen lymph nodes in the neck, armpits, throat, or groin.
Sleep is particularly effective at the beginning of inflammation, such as an influenza infection. If you allow yourself the necessary rest not at the beginning of the illness but only after a few days, when the sickness already has started, it will be too late in terms of strengthening your immune system at night.
Why deep sleep is essential for curing a disease
In deep sleep, the communication between the different groups of defense cells is at full speed, which is why this sleep stage is essential for strengthening the immune system in the case of acute infection. It helps the immunological memory so that the body can better react to a renewed attack of viruses or bacteria in the future.
“Sleep yourself healthy” – there is a lot of wisdom in these words. It is crucial whether a virus encounters an immune system weakened by chronic lack of sleep or a well-functioning immune system. In the latter case, the virus has a much harder time unfolding because the immunological memory is intact and the immune system is fully operational.
Therefore, the best thing to do is to stay at home for a day as soon as you feel an illness coming on and get a good night’s sleep. Then your immune system has an excellent chance to stand up to the pathogens and nip the inflammatory process in the bud.
Why lack of sleep might be linked to cancer
Remember that sleep protects you from all diseases where the immune system is compromised, from less severe ones like an abscess to more serious conditions like cancer. If the immune defenses are weakened by poor sleep, a bacterium, virus, fungus, or parasite has an easier time thriving.
Although this hasn’t yet fully proven for individual cases concerning cancer cells, it can be seen in a group of employees – shift workers. Due to the constantly changing sleep-wake rhythm, which leads to chronic sleep deprivation, shift workers develop cancer more often than people with regular work schedules.
Another explanation for the increased cancer risk among shift workers is their chronically low melatonin levels. The sleep hormone melatonin also has anti-inflammatory and anti-carcinogenic properties, which you lack if you don’t get enough restful sleep during the dark hours of the day.
How to make sleep a priority?
As you can see, sleep is the single most effective thing you can do to prevent disease, ward off a virus and increase the efficacy of vaccination (and it’s free!). Here are some critical actions you can take from today to make sleep a priority:
- Stick to a regular sleep and wake-up time every day – don’t hit the snooze button!
- Keep your bedroom cool and dark.
- Relax your body and mind before going to bed. It’s a good idea to take a shower or bath before bed to cool your body down. You can also meditate or listen to soothing music and engage in end-of-the-day rituals like drinking a cup of chamomile tea.
- Turn off all electronic devices at least half an hour or more before bed. Yes, I know, that’s tough! ;). But electronic devices emit so-called “blue light” that disrupts our sleep patterns.
- Stop drinking caffeine in the early afternoon.
- Avoid large meals in the late evening and let your digestive system rest during the night (ideally for 12 hours). This way, your body can focus on its repair. This is also a helpful strategy for weight loss.
- Remember that alcohol is not a sleep aid. Your body needs time to process alcohol, and while it can help you fall asleep, it increases the likelihood that you will wake up restless during the night.
- If you wake up in the night and can’t get back to sleep after a few minutes, don’t panic! Accept your wakefulness and all the thoughts and emotions that come with it. You may also get up and go somewhere else to do a calming activity, such as reading, meditating, etc. Remember that it’s normal for some people to wake up during the night, so don’t stress and stare at the alarm clock.
- Keep track of your sleep patterns by using a Fitbit or sleep diary. This will help you determine if certain foods or activities are helping or disrupting your sleep patterns.
These are just a few things you can do to improve your sleep. Keep in mind that sleep is a natural and automatic process that we all have within us. This also means that we cannot control our sleep as we like to. Often, the harder we try to sleep, the more elusive sleep becomes.
This is especially true if you have chronic insomnia. The key is always your behavior, such as what you’re doing during the night when you lie awake in bed and how you respond to your internal state of mind and the external stimuli that determine how good you can sleep.
If you want to learn how to better manage insomnia and return to restful sleep without using sleep medication, check out my popular online course The DIY Insomnia Cure.