The loss of one night’s sleep is followed by ten days of inconvenience
Chinese Proverb
I recently had a very bad nights sleep and the next day I happened to read this article. The combination of these two things made me think I needed to think more seriously about sleep both for myself and for my patients. The place I turned to for advice was the Yang Sheng or Nourishing Life tradition of ancient China. But before looking at what the ancient Chinese had to say about how we might improve our sleep I think its worth looking at how recent research has shown just how important proper sleep really is. While a poor nights sleep may leave one struggling through the following day, forgetful and inefficient, the effects of persistent poor sleep can be potentially more serious.
Many of the effects of poor sleep, either insufficient sleep or poor quality sleep, are quite well known. Numerous studies have shown that poor sleep reduces the bodies immune response making us more susceptible to all sorts of infections. There are links between poor sleep and obesity. Because a lack of sleep leaves one short of energy the body naturally craves energy dense foods (think sugars and fats) to compensate. This may be one reason why poor sleep is linked to an elevated risk of cardiovascular disease, but perhaps not be the only reason. Another study looked at people following four healthy behaviours (diet, exercise, not smoking and only moderate alcohol consumption) and found that those who regularly slept more then 7 hours a night had a reduced incidence of cardiovascular disease. But there may be even more subtle health effects linked to poor sleep.
The article mentioned above is fascinating. Our brain is our most active organ. It comprises 2% of our body weight but uses 25% of the calories we consume and in the process is produces large amounts of waste products; beta-amyloid for instance which has been associated with Alzheimer’s disease. During deep sleep our brain is washed by cerebrospinal fluid which flushes these wastes from the tissues of our brain.* This process is most active during slow wave sleep which predominates in the early hours of the morning and as we age we naturally get less of this sort of sleep. So it seems that the lack of sleep, or the absence of the right sort of sleep may actually have long lasting implications for our health. And this of course leads naturally to our asking how we might improve the quality of our sleep.
The ancient Chinese recognised the restorative power of sleep and developed a wide wisdom about how best that power might be harnessed. Like most things in traditional Chinese thought the starting point is the interplay between Yang and Yin. While Yang is light, upright, outwardly focused and dominates during the day, Yin is dark and withdraws inward and so is associated with sleep. In fact sleep is the extremity of Yin within which our body and mind are nourished and restored. In ancient China it was thought that some preparation was necessary if one was going to most effectively enter this Yin state.
For those who sleep poorly the idea of making sure the body is tired before trying to sleep is both appealing and common. But the relationship between exercise and sleep is less easy to pin down. It seems true that those who exercise more report better sleep, but this may simply be that those who sleep better have more energy and so are more inclined to exercise. The studies that there are suggest that exercise isn’t going to solve sleep issues in the short term and that at least several months of regular aerobic exercise are needed before any benefits become apparent. These studies relate to conventional aerobic exercise which may, especially if its being done late in the day or in the evening, actually make getting off to sleep harder.
Aerobic exercise increases the production of adrenaline and cortisol in the body, both of which make sleep harder: adrenaline increases heart rate and warms the body, while cortisol is the ‘fight or flight’ hormone. In the absence of stress the production of cortisol in the body follows a circadian rhythm, with an early morning peak that gets us out of bed, followed by a steady decline in cortisol levels through the rest of the day. So what should we do if early morning runs simply aren’t possible?
One possible solution that the Yang Sheng tradition points to is Asian mind/body practices such as Qigong, Yoga and Tai-chi. These practices have a number of things in common. One is the integration of breath/body/mind. This helps to foster a quiet mind, the very opposite of that most commonly stated cause of insomnia, a ‘racing mind’. Another quality these practices share is the emphasis on relaxation in the midst of effort, which may mean these forms of exercise don’t increase cortisol levels in the body in the way more conventional exercise does. To use traditional Chinese terms conventional aerobic exercise is Yang in nature while these mind/body practices help the body become more Yin.
Of course we don’t just need to prepare the body for sleep but also the mind. We live in an always on culture in which media in many forms constantly grab for our attention with mentally and emotionally stimulating content that keeps us outwardly focussed and actively engaged with the world. While the ancient Chinese weren’t binge watching box sets the Yang Sheng tradition recognised the problem, suggesting that people should refrain from reading and studying in the hours before bed. In fact traditional advice was to sit quietly before bed. This quiet sitting is in fact a suggestion to spend some time meditating immediately before going to bed. Recent studies have shown that regular meditators spend more of the night in deep restorative sleep. In fact meditators aged 50 – 60 years old spent as much time in slow wave sleep as non-meditators who were 20 years younger and slow wave sleep is the sort of sleep associated with the brain being washed with cerebrospinal fluid. And of course the practice of meditation actively teaches us to put down those racing thoughts that so often seem to stop us sleeping.
The Yang-Sheng tradition also offers some more general advice about sleep. It suggests that sleeping on one’s side is best, preferably curled up in a foetal position. This is actually the most common position which people naturally adopt when sleeping but its particularly important for anyone with or who suspects they may have sleep apnoea. Even mild sleep apnoea can have a major impact on the quality of our sleep. Mild apnoea may not actually wake the sufferer but may still stop them slipping into the deeper and more restorative types of sleep. Sleeping on one’s side would preclude high pillows which were considered detrimental to good sleep but herbal pillows were sometimes suggested; for instance dried mint for headaches and throat disorders.
Advice about how long to sleep is also provided by the tradition and again follows the principle of Yin and Yang. This advice is of course modified according to the health, age, constitution, activity and gender of an individual. But the basic idea remains the same; sleep during the hours of darkness and get up with the light. A pattern that would correspond with a healthy body’s natural pattern of cortisol production. The exception to this seems to be the siesta or power nap, where a short sleep just after midday has been correlated with improved mental functioning and lower risk of heart disease.
In the 17th century Li Yu wrote
“The secret of health preservation is first of all sleep… it is an ever successful panacea that cures all diseases”.
Maybe that pushes it a little too far, but there is no doubt that poor sleep can negatively impact our health in a wide variety of ways, while a good nights sleep can not just mitigate those effects but make our days easier and more pleasant. Given the importance of sleeping well its not something we should take for granted and the Yang-Sheng tradition offers some sensible and accessible advice for how we can all improve our sleep.
* This idea of our brains being ‘washed’ brought to mind the a Qigong practice called ‘Brain/Marrow Washing’ Qigong. I have to say this isn’t a subject I know much about but I believe the practice was designed to increase the longevity of the practitioner. Much Qigong practice works with breath work coordinated with body movements and I did find a research paper suggesting that respiration may play an important role in moving cerebrospinal fluid though the brain. Certainly subjects I’d like to investigate further
Further reading
Bruce Bell is an acupuncturist working from clinics in Midsomer Norton and Keynsham