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The immune system is our body’s natural defense mechanism which is made from a network of cells, organs, and tissues which cooperate together to protect our health. A healthy immune system is able to produce cells that fight against different bacterias, viruses or infections. When our immunity is weakened, we experience the feeling of chronic fatigue, persistent colds or repeated infections, because our body is not strong enough to deal with invading bacteria. Disorders of the immune system can develop some autoimmune diseases; for example, in case of increased immune system activity, our body will attack its own healthy tissue and damage it.
We tend to connect the state of our immune system to some healthy living habits such as eating a lot of vegetables and fruits, taking enough vitamins or taking care of our health in general. But we often forget that sleep is also one of those beneficial habits that have an impact on our immune system. Unhealthy sleep habits can weaken our immunity and make us more liable to viruses and illnesses. When we are ill, we feel like we need more sleep and rest in order to recover faster, so the relationship between sleep and immunity exists, but it is complex, and we are going to try simplifying it for you.
The Role of Cytokines
Many different cells produce cytokines, a category of proteins which controls cell activity and signaling, i.e., they control body’s immune response, but they also regulate our sleep since they interact with hormones and neurotransmitters that signal the neurons in our brain. Cytokines have been well known for their defensive role, but some theories imply that their primary purpose was sleep regulation. Anyhow, cytokines coordinate the communication between the brain and immune system, and some particular cytokines like IL1 or IL6 have an essential role in sleep regulation, a higher level of IL1 and IL6 has been linked to some chronic diseases, and it shows the connection between the lack of sleep and health. Our immune system has its rhythm of working, so during the night, the level of proinflammatory cytokines and T-cells is at its highest, while the level of anti-inflammatory cytokines and leukocytes rises during the day.
When we are ill, we need the higher level of certain cytokines, but sleep deprivation causes a decrease in the production of those protective cytokines, and the number of cells and antibodies that should fight against infections is also reduced due to the lack of sleep. That only prolongs our recovery and struggling with the illness.
Many aspects of correlation between sleep and immunity are yet to be discovered, but what is known is that some parts of our immune system contribute to the control of sleep, while the amount of sleep we get impacts on the functioning of immune system. The reason why our sleep and immune systems function so closely is that some substances in charge of immune defense are released or created during the night, while we sleep.
Sleep Deprivation and Immune System
Can you get sick from lack of sleep? Yes! Many people get sick when they are not getting enough sleep, which just confirms how these two things are tightly connected. Recently many different studies were taken to inspect and verify how that connection works, and we are going to summarize a few of them below.
The researchers from the University of Washington performed a study in which they followed eleven pairs of identical twins with different sleeping patterns. They came to the conclusion that the twin who was sleeping less had a weakened immune system. They showed that the immune system works the best when we are well rested, which implies that we need around seven hours of regular sleep to keep our immune system at its highest.
In another study, researchers from the United Kingdom and the Netherlands were following changes in white blood cells after the loss of sleep. This study was performed on 15 young men, and it lasted for two weeks, during the first week they were sleeping for eight hours per night, and they had a limited intake of coffee and alcohol. During that first week, they established a healthy circadian rhythm, which was only an introduction to a week of sleep deprivation. In the second week, during the night the number of white blood cells called granulocytes increased in a reaction to the stress caused by sleep deprivation. Although this was a small study, it contributed to a better understanding of how poor sleep breaks down our immunity.
Some other tests showed that flu vaccine does not perform its best on people who experience chronic loss of sleep. Young students with and without insomnia were compared to check would they react differently to the influenza vaccine shot. Results showed that healthy people with insomnia are jeopardizing their immune system and making it more vulnerable since the effects of the vaccine were lowered on them.
A team of researchers from Tuebingen, Germany, was working on a research about the effects of sleep on the immune system’s T cells. They took some T cells from volunteers who were awake and from those who were sleeping and analyzed them. When compared, samples of T cells from persons who were sleeping had a higher level of integrin activation in comparison to the ones from persons who were wide awake. That result indicates that sleep has a positive effect on the functioning of T cells as a part of the immune system.
How to Improve Your Sleep Quality?
Since we have seen how important sleep is, we would now like to share some tips that can enhance your sleep quality and your immunity at the same time.
- Routines – find something relaxing and stress-free which you can practice each night before bed. Read a book, try solving crosswords or practicing some yoga poses.
- Schedule – take control of your sleep/wake cycle by going to bed and waking up at the same time every day. Weekends should not be an exception from it.
- Mattress – the choice of mattress can have either harmful or good impact on your sleep quality. For a night of proper rest, it is essential to find the one that will suit your body preferences and needs.
- Blue light – electronic devices that surround us emit this so-called blue light, try avoiding these devices before going to bed or install apps for smartphones and laptops that block blue light.
- Melatonin supplements – sleep aid is a common thing nowadays, and since melatonin is the hormone in charge of sleep, people who have troubles with falling asleep or suffer from insomnia reach for melatonin supplements since they will make you fall asleep faster.
- Stress – as hard as it can be, try keeping the stress and problems away from your bedroom and find something to do before falling asleep instead of overthinking and getting more upset.
- Sleep disorder – we all experience troubles with sleep once in a while, but if you are not satisfied with the quality of your sleep or you feel that nothing is helping, consult your doctor and check if you have some sleep disorder.
Food That Can Boost Your Immunity
We have all heard the “an apple a day keeps the doctor away” expression, and not only that it rhymes, but it is true. Fruits and veggies contain many vitamins that are beneficial for our immunity, but besides them, it is essential to eat various food because eating just one type of food would not be enough. Timing is also essential for sleep, we should not eat late at night or right before bedtime, and that does not only stand for snacks and junk food, but it also stands for healthy food too. Meals should be well balanced, so no starving or overeating, and try establishing a routine and eating every day at the same time. Now we are going to see which foods can strengthen our immune system, but, also, check out our list of best foods for sleep which also includes the selection of foods that prevent sleep.
- Citrus fruits – The most popular vitamin is probably vitamin C, which we all reach for as soon as we feel ill. Vitamin C improves the production of white blood cells that are in charge of fighting against infections. It is interesting to know that our body does not contain or produces vitamin C, so we have to intake it through different citrus fruits which are rich with vitamin C. Some widely available citruses are lemons, oranges, tangerines, clementines, limes, etc. You can either eat them or make a mixed squeezed juice out of them.
- Vegetables – Although citruses contain a lot of vitamin C, there is one veggie that contains two times more vitamin C than citrus fruits. Any guesses what it could be? The red bell peppers are absolute winners when it comes to vitamin C, and they also contain beta carotene which is beneficial for eyes and skin. Another vegetable that is packed with vitamins is the infamous broccoli. Children’s least favorite veggie probably the healthiest vegetable that exists, it contains vitamins A, C, and E, fiber and many antioxidants. Garlic, spinach, and ginger are also highly recommended for boosting the immune system and fighting the cold.
- Nuts – many other important vitamins are in the shade of widely famous vitamin C, but another crucial vitamin for our immunity is vitamin E. Nuts such as almonds, walnuts, pistachios or hazelnuts are all packed with this vitamin, and they also contain healthy fats. Small handful portion of nuts per day will satisfy your vitamin E needs, but since they are so high in fat, you should not exaggerate with the daily intake of nuts.
- Yogurt – if you are searching for vitamin D which regulates our immune system, you will find it in yogurt. Greek yogurt, for example, contains active and live cultures which can also be found in some other yogurts, and since those cultures can stimulate your immune system to fight against the illness, they are highly recommended. Avoid buying flavored yogurts because they have a higher level of sugar, instead buy a plain one and add pieces of fruit or honey to flavor it up.
- Chicken soup – the favorite remedy of our moms and grandmothers, chicken soup, can help with symptoms of a cold or flu. Poultry like chicken or turkey contains a lot of vitamin B-6 which is essential for creating red blood cells. Around 3 ounces of chicken meat will satisfy half of your daily need of vitamin B-6.