In the latest episode of the Vilnius University podcast, she explains what happens in the human brain during sleep, why sleep is vital, how to get a good night's sleep, and in what way the sleeping brain differs from the non-sleeping brain.
Sleep reverses the damage the body suffers during the day
"Sleep is vital for your physical, mental, and emotional health. It as well affects our mental function. Most of the time, sleep deprivation leads to more stress, lower mood, and difficulty concentrating. This is proven by research: sleeping too little or not getting enough quality sleep damages absolutely every system of our body, including immunity, mental function, heart and blood vessels, hormones, and digestion. It increases appetite, reduces satiety and can lead to weight gain," warns Dr Bojarskaitė.
She emphasises that when it comes to taking care of your sleep, the big picture matters. Thus one must not worry because of one or two sleepless nights. All studies show that too little sleep is harmful if it is a long-term issue lasting months or years.
"During sleep, certain restorative processes occur throughout the body - in the brain, organs, and physiological systems. To put it simply, sleep is a state in which, after an active day, all the 'damage' to the body caused by our activity is reversed, and everything is restored. So sleep is like the price we pay for being awake and active during the day. Sleep enables the repair processes of our cells and tissues so that we can get up feeling refreshed and ready for a new day," says the researcher.
Sleep needs vary from person to person: the key is tracking your wellbeing
Dr Bojarskaitė identifies several types of sleep. Evidence shows that during deep sleep (also called slow-wave), the body's physical repair processes take place. Growth hormone is released to rebuild muscles and bones; therefore, it is critical for children. REM sleep is a time of mental and emotional recovery. However, all sleep types are interlinked and, therefore, important. It is essential not only to get enough sleep but also to maintain the rhythm, i.e. going to bed and getting up at similar times. To have good quality sleep, we should abstain from overeating, coffee, alcohol, and over-smoking before bed.
"What is the minimum amount of sleep we need? The amount that is enough for a specific person, I would say. As many studies suggest, an average healthy adult should get 7-8 hours of sleep every night. If we consistently sleep more or less than 7-8 hours, we may experience an increased risk of disease. But everyone is different. As well we are in different stages of life. Therefore, the need for sleep varies. The optimal sleep duration is between 6 and 9 hours," says the researcher.
According to Dr Bojarskaitė, the amount of sleep we need is determined by various individual and external factors. If we are physically and mentally active during the day, we will need more sleep to compensate for the increased damage to the body. The same applies in the case of illness. In summer, when there is a lot of light at our latitudes, we sleep less than in winter when there is less light. The need for sleep varies with age. It depends on the stages of life. That is why it is most important to keep track of your wellbeing.
Should we take naps?
"Napping for 20-30 minutes during the day is also great, as it restores your mood and energy. The most important thing is not to let those naps disturb your night’s sleep. Naps also help when you have not slept enough at night," says the researcher.
Is it possible to get enough sleep in advance? According to Dr Bojarskaitė, in the ideal scenario, we should get enough sleep daily: “However, in reality, it is quite a challenge. Sleeping less on weekdays and compensating by sleeping a couple of hours more on weekends is a bad strategy. Studies show that it negatively affects health in the long run. With that being said, not getting enough sleep is even more dangerous. Thus, if you don't get enough sleep during the working week, I would say it is all right to get more sleep at the weekend."
However, the researcher advises against it as a long-term strategy. She also suggests that weekends make it very easy to lose the rhythm, as you go to bed and get up at different times, and it can be difficult to get back on track.
Night work should be better paid and reserved for night owls
Research shows that shift or night work is bad for your health. But in our world, we can only do with people who take up such duties. According to Dr Bojarskaitė, they are heroes who should be rewarded with very high salaries, health benefits, early retirement, and additional holidays. The state should contribute more to restoring the health of night work people. In some countries, such initiatives are already in place.
What can be done to reduce the damage caused by irregular sleep patterns? At least, one should try to get the same shift to ensure regularity. Routine is essential for the body. For people working shifts, it is advisable to have coffee only at the beginning of the shift, as coffee at the end can harm sleep. Finally, I recommend wearing sunglasses on the way home to avoid being agitated by the light. One should try to get enough sleep at home and have a nap before their shift," recommends Dr Bojarskaitė.
In future, she believes, night owls should do shift and night work, as it is common for people of this chronotype to go to bed later and get up earlier: "Their genes or their surroundings partly determine people's chronotype. We can talk about a whole spectrum, from entirely early birds to absolute owls. Most people are in the middle of the spectrum, going to bed around 11 pm and getting up around 7 am. Studies show that owls are in poorer health than early birds. This is because our society is geared only toward early birds. In the most advanced companies, there is a move towards adapting working time to the chronotype of the employee. This benefits both the employer and the employee, as maximum productivity is achieved."
Sleep hygiene: stick to your routine and forget the snooze button
"The most important thing is routine: going to bed and getting up simultaneously. This way, we train our body to do the work for us: it makes us sleepy at our bedtime and wakes us up at our wake-up time. Secondly, it is important to get natural sunlight in the first half of the day. Through our eyes, it encourages the central clock in the brain to send signals to our whole body and announce the start of the day," says the researcher.
She advises avoiding bright light and not drinking caffeine in the evenings. Caffeine interferes with sleep by increasing the number of awakenings and reducing sleep quality. The last caffeinated drink should be taken at least 8 hours before bedtime. It is also important to set aside at least a couple of hours in the evening to calm down, not for work but for relaxing activities. Finally, it is crucial to follow the rule that the bedroom is for sleeping, not working.
"Physical movement, being active, also help us sleep: we fall asleep more easily and sleep better. One should also not overeat before going to bed. However, going to bed hungry is to be avoided as well. The last, lesser-known advice is to go to bed when sleepy, i.e. not too early. Laying down and not being able to fall asleep causes anxiety and pseudo-anxiety. Go to bed when you are sleepy, and you won’t set yourself up for problems," advises Dr Bojarskaitė.
She is convinced that the snooze function on the phone is stressful for the body and heart. Thus it is better to avoid using it: “I would like to clarify that counting sleep cycles doesn't work because the average sleep cycle is 90 minutes. However, the individual sleep cycle of each person lasts between 60 and 120 minutes on average."
All smart devices for tracking sleep duration do function accurately. Yet, they are inaccurate in tracking the stages of sleep, i.e. deep sleep and REM sleep. Sometimes people get shocked by their deep sleep stats on a smart device, which may be because of inaccurate tracking. Sleep stages can only be accurately tracked by measuring brain activity in clinics and laboratories, employing specific electrodes. Intelligent devices, on the other hand, rely on secondary indicators such as heart activity, temperature, etc.
