It may happen that after 7 or 8 hours of sleep you wake up still tired, or that the night is characterized by a light sleep with continuous awakenings. Well, the problem could be in the time our body spends in that phase called deep sleep. In fact, sleep is as vital to our existence as eating and drinking, but just as important is the quality of sleep. In fact, sleep is not all the same but is composed of various phases, classified into non-REM and REM. We are interested in the third stage of non-REM sleep, called deep sleep or slow wave sleep. Let's try to understand its importance and what we can do to improve this part of our sleep.
Deep sleep, what it is and what it is for
Deep sleep is that phase of sleep that is essential to make you feel rested and refreshed the next day (Source NIH, National Institute of Health). It usually occurs in the first part of the night, the heartbeat and breathing slow down, the muscles relax and it becomes very difficult to wake up or, if it happens, the feeling is to be disoriented, even for several minutes (Eugene et al, MEDtube Sci, 2015). The brain waves that characterize this phase are low-frequency waves of the delta type, considered capable of stimulating the processes of detoxification of the brain from those harmful substances that could open the way, in the long term, to neurodegenerative diseases such as Alzheimer's (Fultz et al, Science, 2019). The brain uses the deep sleep phase to store information learned during the day and creates the basis for staying efficient and active the next day. It has been observed that the deep sleep phase is essential for an efficient learning process (Fattinger et al, Nat Commun, 2017). Not only that, the deep sleep phase is one in which the body regenerates damaged tissues, muscles repair themselves and the immune system is strengthened (Patel et al, StatPearls Publishing, 2021). When the body spends too little time in the deep sleep phase, it can happen that you wake up already tired, have problems with concentration and attention, have more difficulties in learning and memorization processes and be more prone to infections. But how to avoid all this? This is certainly the hardest part as it is not possible to command the brain to spend more time in the deep sleep phase, it is something that is beyond our control. However, some habits have made it possible to promote the phase of deep sleep.
How to prolong deep sleep, essential oils
One way to prolong the deep sleep phase is to use some types of essential oils, such as lavender essential oil. It has been observed that releasing this essential oil into the room during the night, or at least during the first phases of the night, has allowed to promote the phase of deep sleep, with an improvement in the quality of sleep and a feeling of greater tone during the day (Ko et al, Sci Rep, 2021). The blend of lavender, ylang ylang and bergamot essential oils has also been shown to exploit the synergy of these essential oils in order to improve sleep quality, promoting deep sleep with fewer nocturnal awakenings (McDonnell et al, J Altern Complement Med, 2019).
Some sounds, if listened to before going to sleep, can promote deep sleep. An example is given by pink noise, a type of sound in which the low frequency components have greater power, unlike white noise where each frequency has the same power (Schade et al, Nat Sci Sleep, 2020). In the Relax Area section of the app, among the list of sounds you can choose to listen to the pink noise.
Extracts from the leaves of a plant, apocynum venetum, have been shown to lengthen the phase of deep sleep by 7% (Yamtsu et al, Journal of Nutritional Science and Vitaminology). An even better effect was observed by combining this plant with a supplement based on the neurotransmitter GABA, which made it possible to reduce the time to fall asleep (Yamtsu et al, Journal of Nutritional Science and Vitaminology).