Sleep is not a passive moment but a part in which our body carries out processes that can protect brain health, improve memory and make us wake up full of energy. If something jams in this delicate mechanism then toxins can accumulate in the brain, memory cannot work at its best and we wake up already tired. Today we are talking about sleep, the various phases of which it is composed and what we can do to stimulate the deep sleep phase, which is the phase in which the brain cleans itself of harmful substances and regenerates us.
The different stages of sleep
Sleep is not all the same. The moment we close our eyes, different phases of sleep alternate, which can be divided into the two major phases NREM, or non-rapid eye movement sleep, namely the phase in which there are no eye movements and which leads to the deep sleep phase, and REM sleep, or rapid eye movement sleep, characterized by rapid eye movements and which is the dreaming stage. The alternation between these phases can also occur 4-5 times per night (Eugene et al, MEDtube, Sci, 2015). Today, as mentioned, we will focus on NREM sleep and in particular on one of the parts of which it is made up, which is the phase of deep sleep. We will try to understand what happens in particular in this phase and how to promote it, for the well-being of body and mind.
Deep sleep, the benefits
Deep sleep is the part of sleep that regenerates the brain and stimulates brain detoxification processes. In fact, studies have shown that during deep sleep the spaces between neurons increase by 60%, allowing a better flow of interstitial fluid and therefore allowing the brain to more easily get rid of neurotoxic substances, such as aggregates of beta amyloid proteins, one of the causes of Alzheimer's (Xie et al, Science, 2014 - Val Alphen et al, Sciences Advances, 2021). Not only that, a disturbed sleep, which presents an interrupted and therefore less effective deep sleep phase, causes a worsening of memory and cognitive functionality (Xie et al, Science, 2014). On the other hand, deep sleep, when it has no interruptions, restores the brain's ability to learn and store information, acting above all on those brain areas most activated during the day (Fattinger et al, Nat Commun, 2017).
Deep sleep, how to promote it with nutrition
What we eat can affect the quality of sleep. In particular, favoring foods low in fiber but high in saturated fat has been shown to reduce the time spent in deep sleep. Not only that, an increase in the consumption of refined carbohydrates and sugar has also led to an increase in nocturnal awakenings, with a reduction in the time dedicated to the deep sleep phase (Sejbuk et al, Nutrients, 2022).
Deep sleep, here are the essential oils that help
Inhaling lavender essential oil before going to bed and during sleep has been shown to improve sleep quality and promote deep sleep phase. The immediate consequence, in the volunteers who had participated in the study, was a feeling of greater energy and tonicity the following day to underline the regenerative capacity of deep sleep (Goel et al, Chronobiol Int, 2005 - Ko et al, Sci Rep, 2021).
Deep sleep, recommended sleeping positions
Even the position we sleep in can make a difference. In fact, studies have observed that, in order to improve the quality of sleep and promote deep sleep, sleeping on the side is the best position to obtain these benefits. In fact, the position on the side reduces the risk of sleep apnea, which can alter our sleep (Ozeke et al, Sleep Breath, 2012). Not only that, several scientific studies have shown that sleeping on the side, rather than on the back or stomach, stimulates the detoxification processes of the brain that cleans itself of toxic substances, including aggregates of beta amyloid proteins, which, as previously mentioned, are one of the causes of Alzheimer's (Lee et al, J Neurosci, 2015). Sleeping in the prone position, on the other hand, slows down the brain cleaning processes and makes them less effective (Lee et al, J Neurosci, 2015). And if your problem is esophageal reflux, which can disturb your sleep and cause you to wake up at night, perhaps interrupting your deep sleep phase, then, based on scientific studies, it can be helpful to sleep on the left side. This position, in fact, reduces reflux episodes during night rest and the exposure of the esophagus to acid (Person et al, J Clin Gastroenterol, 2015).
To sleep better here is the slow breathing technique
Applying the slow breathing technique before going to sleep allows you to counteract any state of hyper-excitation before going to sleep and to improve the quality of sleep and thus its regenerating action. In particular, slow breathing stimulates vagal tone and the parasympathetic nervous system, which is the part of the nervous system that promotes relaxation (Jerath et al, Front Psychiatry, 2018). To apply this technique, inhale through your nose for a count of 4 seconds, then hold your breath for 7 seconds, then exhale for 8 seconds. Repeat for a few cycles.