Which physiological activity occupies most of our lives? Yes, it is sleep. We spend 25–35% of our life sleeping, which means at least 25 years, considering the average life expectancy in Poland, which is 78 years. Therefore, it is surprising how little importance we, as well as medicine and lifestyle recommendations, attach to sleep and its role in our health and everyday functioning.
Recent scientific achievements prove that, even though underestimated, sleep plays an important role in our well-being, joy of life, success in education and work, body’s immunity, and the risk of many diseases. Therefore, it is worth learning more about sleep and its significance to health.
HOW IMPORTANT IS SLEEP FOR OUR HEALTH?
Sleep is not just a switch that turns our consciousness off for a while. Despite reduced activity and energy consumption, many useful biological processes take place in the brain and the whole body when we sleep. In short, the most important activities include:
• Organisation and recording of information, getting rid of unnecessary “garbage” from memory – sleep deprivation makes it difficult or even impossible to learn and remember;
• Reorganisation and communication between nerve cells –sleep deprivation makes our brain less productive over time;
• Rest and regeneration of most tissues and organs of the body, and production of beneficial amines and hormones – without sufficiently long sleep, the body has no chance to regenerate, in adolescence – for proper development and growth, whereas in later stages of life – to rebuild damaged cells and accumulate energy, i.e. recharge.
These processes are essential for health. Without sleep, our body cannot function properly.
Sleep is a complex physiological process. We can distinguish two fundamental, alternating stages of sleep:
• Non-rapid eye movement (NREM) stage, and
• Rapid eye movement (REM) stage.
The NREM stage, which is divided into several more sub-stages depending on the depth of sleep, is longer and allows us to rest and recharge. During the much more active REM stage, the brain is more stimulated, and this is when we dream. To consolidate memory and regenerate thinking, both stages of sleep are necessary. Each sleeping cycle, lasting on average about 80–120 minutes, consists of both NREM and REM stages in different proportions. In order to get enough sleep, we need 4–6 sleep cycles depending on their length and genetic conditions.
The valuable influence of sleep on health and psyche has been known for a long time, but only recent scientific studies have confirmed its importance for the proper functioning of the body. Sleep deprivation may result in:
• Reduced concentration and cognitive functions, difficulty learning and remembering;
• Mood disorders, anxiety and even depression;
• Weaker physical performance, easier fatigue, deterioration of sports performance;
• Decreased immunity, greater susceptibility to infections and diseases;
• Metabolic disorders leading to being overweight or even obese;
• Increased risk of chronic diseases, such as diabetes, hypertension and other cardiac diseases, including arrhythmia.
To sum up, more serious disorders leading to long-term sleep deprivation, as well as poor quality of sleep might even lead to early death, but certainly shorten the life span and reduce good health.
HOW CAN SLEEP AFFECT OUR HEALTH SO EXTENSIVELY?
It is easy to understand the negative impact of sleep deprivation on the clarity of mind, memory and ability to learn, as probably everyone has had such an experience, preparing for an exam or an urgent task at work.
To put it simply, the memorisation process can be divided into 3 stages:
a) cognitive stage, when we learn or experience something new,
b) consolidation stage, when we consolidate the memory in the brain, and
c) recall stage, when we use the information stored in our memory.
Sleep deprivation has an adverse effect on all these stages, particularly memory consolidation. It affects both long-term and short-term memory.
SLEEP VS. STRESS AND FITNESS
Sleeping problems are inseparable from stress, mood disorders, depression and other mental illnesses. As a result of sleep stages being too short or even non-existent, the secretion of neurotransmitters and stress hormones is disturbed, which results in deteriorated thinking, nervousness and other negative emotional reactions, as well as intensification of mental symptoms, particularly if some psychological problems have already existed. Conversely, difficulty falling asleep, waking up at night and in the morning can be an early sign of unconscious stress or even more serious mood disorders, anxiety reactions or depression. People suffering from insomnia have a 10 times higher risk of this serious illness.
Therefore, sleep problems may be one of the causes of mental problems, as well as one of the symptoms and factors exacerbating such conditions. Furthermore, statistically, men who sleep for 4–5 hours have the same testosterone levels as men who are ten years older.
Proper sleep is a prerequisite for good physical condition and performance, and all professional athletes are aware of this. Practically all the areas listed above that are affected by sleep are important for physical and mental fitness, which is important for sports competition.
Sleep deprivation results in reduced motor coordination, faster fatigue as a result of abnormal metabolic functions, longer response time and often increased risk of injuries, but also longer time needed for rest and regeneration after physical activity. Sleep is important not only for athletes, but for all those who lead an active lifestyle, because the health benefits of exercising in a gym or recreational jogging can simply be impeded or eliminated by sleep deprivation.
Proper sleep has a significant positive effect on the immune system, and its absence or deprivation results in reduced immunity. Studies have shown that, in the case of sleep deprivation, the number of Th1 lymphocytes drops, whereas the level of inflammatory cytokines increases. As a result, our resistance to infections and diseases decreases and even reduces the beneficial effect of vaccinations, e.g. against the flu. Sleep also helps with other natural body defences, such as fever. As we all know, temperature rises in the afternoon, in the evening and at night. During an infection, we sleep a lot, so the body has a chance to fight the disease.
The last thing to consider in treating insomnia is taking sleeping pills. Specialists (according to the American Academy of Sleep Medicine) recommend that you first change your habits:
• Ensure regularity – go to bed and wake up at the same time, whether on a weekday, weekend or holiday. If you do not fall asleep within 20–30 minutes, get up, read or listen to calm and relaxing music, and then go back to your bedroom after you get sleepy.
• Pay attention to the right conditions – darkness, silence, cool but pleasant temperature in the bedroom, comfortable mattress, bed linen and nightwear made of natural materials.
• Avoid using electronic devices or watching TV – at least 30 minutes before bedtime, and in any case in the bedroom. A short ten-minute meditation is also an effective method of preparing for sleep.
• Avoid hearty dinners, coffee, strong tea and alcohol – eat or drink them about 2–3 hours before bedtime. You can have a light snack if you wake up hungry.
• Ensure an adequate amount of healthy exercise during the day – but remember not to exercise late or just before bedtime.
If the above methods fail to help, and sleep deprivation makes your daily life difficult, it is worth seeking help from a specialist. Depending on the underlying problem of insomnia, you should consult a psychologist or a doctor who specialises in the treatment of sleep disorders. They will help you self-evaluate the course of sleep and your habits, and suggest the appropriate course of action.
It is now believed that the method of choice is cognitive behavioural therapy for insomnia (CBT-I), which focuses on overcoming the misconceptions associated with insomnia, working on excessive mental control and creating normal habits. Recently, a number of treatment support applications have been developed, including one that features the CBT-I therapy.
For example, a tool that has been approved by the FDA (Food and Drug Administration, the US government agency that approves new medications and therapies) is Somryst (https://somryst.com/). However, it is not yet available in Polish. A specialist can advise a suitable application that will be right for the planned procedure.
Only if such psychological intervention fails or if there is a specific cause of insomnia should other individually selected treatments (including pharmacological ones) be considered. Melatonin, often promoted as a medication recommended for sleeping difficulties, has a limited effect. It mainly helps restore the daily cycle after a long journey by plane or among those working shifts. Other medications (including sleeping pills and parapharmaceuticals) should be taken with caution, only for a short period of time, preferably under the supervision and on the recommendation of a specialist.
Studies show that our sleep is too short and that this trend is increasing: even in the relatively short span between 2010 and 2018, the number of adult Americans sleeping less than 6 hours has increased from about 30% to over 35%.
These negative changes can be associated with the popularisation of smartphones and excess stimuli that bombard our senses all day long. If we do not make sure we improve our sleep, diet, nutrition and minimum recommended exercise, the forecast as regards the quality and longevity of our life will be a gloomy one.
We recommend the following books for those interested in learning more about sleep:
• “Why We Sleep: Unlocking the Power of Sleep and Dreams” by Matthew Walker
• “The Sleep Revolution: Transforming Your Life, One Night at a Time” by Arianna Huffington
• “The Sleep Solution: Why Your Sleep Is Broken and How to Fix It” by W. Chris Winter
Author:
Piotr Soszyński, PhD MD, Internal Medicine Specialist