A good sleep is the basis for an active and healthy life. This statement is known and is commonly accepted, also because we can all experience it. Have you ever tried to skip a night's sleep or sleep only for a few hours? In the morning you certainly weren't so fit ... But what exactly does a restful sleep do to our body? And what mechanisms are triggered when we fail to guarantee it? Recent scientific research sheds light on this aspect. Today we are talking about the latest scientific results on why it is essential to sleep well and enough hours. Then, we will also see the advice from prestigious universities to improve the quality of sleep.
The latest from science, the importance of a good sleep
When it comes to hours of sleep, 7 is the magic number. On the other hand, sleeping less than 5 hours a night can increase the risk of getting sick in the long run. In particular, it has been observed that those who, during middle age, sleep 5 hours or less have a 40% higher risk of getting two or more chronic diseases, such as cardiovascular disease, diabetes and cancer, over the next 25 years compared to those who sleep between 7 and 8 hours a night. But beware, sleeping too much is also not good. The same study also showed that, if you already have a chronic disease, sleeping for more than 9 hours increases the risk of developing another chronic disease by 35% (Sabia et al, PloS Medicine, Oct 2022). And that's not all. According to a very recent study, sleep and its duration can also be considered an important indicator of cardiovascular health. This is because those who sleep a few hours a night, less than 6, have a higher risk of having disturbed sleep, having sleep apnea, developing obesity, hypertension and diabetes (Makarem et al, JAHA, Oct 2022). Finally, another very recent research has shown, thanks to computer models, that, during sleep, and in particular in the transition between the REM phase and the non-REM slow wave phase, which occurs on average 5 times a night when sleep is not disturbed, the hippocampus teaches the neocortex what it has learned during the waking period, thus settling the memory. Good sleep, with multiple alternations between REM and non-REM therefore is essential to allow the brain to store what it has learned during the day and transform transient and labile information into something lasting. If, on the other hand, sleep is interrupted and there are not sufficient alternations between these two phases, instead, the memory is overwritten (Singh et al, PNAS, Oct 2022).
Restful sleep, advice from scientists at the Johns Hopkins Center for Sleep
The director of the Johns Hopkins Center for Sleep, Dr. Charlene Gamaldo, offers some useful tips to improve the quality of sleep and thus also of life (Gamaldo, Johns Hopkins Center for Sleep). First of all, the advice is to drink, not alcohol, which disturbs sleep, but rather hot drinks such as milk, which stimulates tryptophan in the brain, in turn involved in the synthesis of serotonin, essential for establishing the sleep-wake cycle, or chamomile, which contains flavonoids that interact with benzodiazepine receptors in the brain, also involved in the sleep-wake cycle. Not only that, tart cherry juice is also useful, which supports the production of melatonin and a healthy sleep cycle. Physical activity, which stimulates the phase of deep sleep, is also very important. However, exercise should not be done too late in the evening as it also promotes the release of endorphins, which keep the body active and awake. This is why it is good to avoid physical activity in the two hours before bedtime. Then, according to the doctors at the Johns Hopkins Center, help also comes from supplements of melatonin, which is a hormone that is released from the brain four hours before you feel tired. These supplements are found in chemist's and herbalist's shops. Another tip is to avoid that the bedroom is overheated, the temperature range between 18 and 22° C is optimal and for women in menopause it is important that the room is very cold, to counteract hot flashes. Finally, the last recommendation is to keep the room dark. In fact, even the light of the smartphone can disturb sleep. What if you have to get up at night? Don't leave lights on to avoid tripping, but use a flashlight, which interferes less with sleep.
Essential oils to promote a good rest
During rest, in addition to keeping the bedroom dark and cool, we also add that it is possible to diffuse into the environment or pour directly on the pillow a few drops of the essential oils that have been shown to improve the sleep quality. For example, lavender essential oil promotes the phase of deep sleep, which is dominated by slow brain waves (Ko et al, Sci Rep, 2021). This fact has not only a beneficial effect on sleep quality, but also, as studies have shown, on brain health, helping to prevent neurodegeneration. In fact, older people with longer deep sleep phases have fewer accumulations in the brain of beta amyloid proteins, the hallmark of Alzheimer's, and this even if the duration of sleep is short (Varga et al, Sleep, 2016). You can also mix the lavender essential oil with other essential oils, for example the essential oils of ylang ylang and bergamot, whose synergy has been shown to improve quality of sleep, helping to reduce nocturnal awakenings and making sleep more restorative (McDonnell et al, J Altern Complement Med, 2019).