Sleep, and in particular one of its phases called deep sleep, is restorative, it allows you to regenerate, sediment the memories learned during the day and cleanse the brain of accumulated toxins, thus combating dementia and Alzheimer's. Hence the importance of protecting sleep and guaranteeing quality rest. What has been said is true for everyone, adults and children, and even more so for the elderly. It seems, in fact, that a reduction over the years in the duration of the deep sleep phase can increase the risk of cognitive decline and neurodegeneration, as stated by very recent research published in the journal JAMA Neurology thanks to a collaboration between American, Canadian and Australian scientists (Himali et al, JAMA Neurology, Oct 2023).
Deep sleep protects the brain, the study
The research involved 346 volunteers, all over 60 years of age and healthy at the time of recruitment, between 1995 and 1998. All study participants were asked to undergo two sleep quality assessments five years apart. This is with the aim of studying the duration of the deep sleep phase, which is one of the sleep phases essential for waking up rested, in which memory is consolidated and the brain is cleansed of toxins accumulated during the day. The volunteers were then followed for an average of 17 years to assess their brain health. What has emerged is that the duration of deep sleep plays a very important role when it comes to preventing cognitive decline and the development of dementia and Alzheimer's. In fact, researchers have measured that every 1% decrease over the years in the duration of the deep sleep phase leads to a 27% increase in the risk of developing dementia and a 32% increase in the risk of developing Alzheimer's.
The study clearly shows that sleep is essential to cleanse the brain of toxins that can accumulate during the day and that a deterioration in the quality of sleep can, in the long run, lead to brain problems. This applies to everyone but for adults and the elderly it is even more important. The authors of the study point out that loss of deep sleep is a factor that increases the risk of cognitive impairment and dementia. However, they also state that this factor is modifiable, meaning that on our side we have various actions available to protect deep sleep, improving the quality of sleep. But what can we do to protect restful, regenerating and healing sleep?
How to protect deep sleep, advice from experts
Here are some tips provided by the Alzheimer's Drug Discovery Foundation (Cognitive Vitality Blog, program of Alzheimer's Drug Discovery Foundation). It is important to try to go to bed and wake up at the same time every day. Not only that, to protect the quality of sleep and thus also the brain, avoid drinks containing caffeine in the evening hours, always avoid alcohol, but, if you want to indulge in these drinks, avoid them at least in the 3-4 hours before going to sleep. Practice regular physical activity, but avoid evening hours. In fact, the advice is to leave more relaxing activities for the evening. Finally, keep the room where you sleep dark and cool.
How to protect deep sleep, melatonin, diet and aromatherapy
Natural remedies and diet can also help to improve the quality of sleep. For example, melatonin can help regulate sleep-wake rhythms and thus improve the quality of sleep. Several scientific articles indicate that melatonin in the form of a supplement is also indicated for the elderly and that, by improving sleep, it can reduce the feeling of grogginess and the risk of falls during the day. In any case, before taking melatonin, it is always important to talk to your doctor. In addition to melatonin, diet also helps. The diet should be healthy and varied. In fact, some nutritional deficiencies, especially zinc, magnesium, phosphorus, selenium and vitamin B1, are associated with shorter sleep phases, while some foods, such as kiwi fruits, cherries, fatty fish and legumes have been shown to increase sleep duration (Frank et al, Front Neurol, 2017). Aromatherapy is another ally. In fact, studies show that inhaling some essential oils helps improve the quality of sleep and lengthen the deep sleep phase. The best essential oil, in these cases, is given by lavender oil, capable of increasing melatonin levels, even in elderly people, while the best mixture of essences is given by lavender oil, ylang ylang oil and bergamot oil (Velasco Rodriguez et al, Complementary Therapies in Medicine, 2019 - Mc Donn ell et al, J Altern Complement Med, 2019).