Sleep and the body clock

The body clock that Professor Williams discusses in Part 3 of the Sleep 101 series, has a counterpart in Chinese Medicine – the Chinese Clock – which I’ll talk about in this post. 

The body clock – the day/night cycle helping us sleep (and wake)

Simply put, the body clock (also known as the circadian clock or rhythm) is a cycle that regulates processes relating to our behaviour, our physiology and our psychology. In humans the cycle runs for about 24 hours and is focused around the activities of day and night and what we supposed to be doing as the cycle progresses. It allows (or maybe, compels) us to respond to the day/night environment and adjust our behaviours and activities accordingly.

Professor Williams talks about the things that shift the body clock out of sync – long haul flights; blue light from our un-put-downable devices; body temperature – and it’s easy to understand how these might have a negative effect on our sleep. While compensating for jet-lag is difficult, we can usually adjust our screen usage and temperature well enough to minimise the negative effects on our sleep.

An interesting aspect of the conversation was the discussion about the difference between difficulty falling asleep, and falling asleep easily enough, but then waking during the night. From Professor Williams’s point of view, it was either a clock issue (not falling asleep); or unconsolidated sleep involving learned behaviours and/or sleep hygiene issues (falling asleep but then waking later). Helpful insights when trying to work out where the sleep problem lies.

The Chinese Clock

From the Chinese medical standpoint, our daily rhythms are governed by the Chinese Clock. This is another 24 hour cycle that divides our day and night into 12 two-hour periods of time, each of which relate to one of the 12 internal organs. Looking at the diagram below, you’ll notice that each organ has its two-hour slot over the 24 hour period. During this time the level of Qi in that organ is at a peak. It follows that twelve hours later the level of Qi in the same organ is in a trough.

The Chinese Clock

How does this affect us?

How does this work in the context of sleep or our general health? Here’s an easy example: the Stomach has its peak (of efficiency, capability, capacity) between 7 and 9 in the morning. It would therefore be best placed to deal with a big breakfast (the most important meal of the day, apparently) at this time of day. Conversely, between 7 and 9 at night, the Stomach would be worst placed to deal with what is often our main meal of the day. Not to say that this is a disaster for everyone, but rather, if you’re experiencing bloating after your evening meal, this might add to the overall view of your health that the acupuncturist is always concerned with.

…to an acupuncturist everything is related to everything else and we find it difficult to view anything in isolation…

Admittedly this doesn’t seem directly related to sleep, but to an acupuncturist everything is related to everything else and we find it difficult to view anything in isolation. A possible interpretation of a patient who experiences discomfort after a heavy meal at night might be that their Stomach is less than robust and this is worth factoring in to our overall treatment plan. A Stomach that is struggling to deal with a big meal is not going to help you sleep and, to an acupuncturist, this would be another factor to pay attention to.

Similarly, the Liver, as we can see, has its peak time between 1 and 3 in the morning. Many patients report that they wake up around 3am, and while this would not definitively translate to the Liver being the sole cause of sleep troubles, it would mean that it would be worth investigating further and adding that information to the overall picture of health in that patient. 

New research

In contrast to the circadian clock, the Chinese clock recognises that each organ has a clock of it’s own – a time when it peaks, a time when it’s in a trough, and a falling and rising continuum between the two poles. Recently however, researchers at Washington State University and the University of Surrey have identified separate biological clocks for individual organs. In one example, by simulating a night shift schedule, the researchers found indicators that the digestive system had shifted by 12 hours, while the master biological clock in the brain had shifted by only two hours.

Both the circadian body clock and the Chinese clock offer a lot of insight into what might be going on with our sleep patterns. We can use the understanding they offer to piece together the lifestyle changes and treatments that are needed to get us in balance and asleep.

Professor Williams’s bio

Professor Williams’s interest in sleep began in 1975 during his tenure at Harvard Medical School with a study in Sudden Infant Death Syndrome (SIDS) which implicated Obstructive Sleep Apnoea as a cause of the syndrome. He became tenured Professor of Medicine at U.C.L.A. and Co-Director of U.C.L.A’s Sleep Laboratory in 1985. He was one of the first to become a Fellow of the American Academy of Sleep Medicine (AASM).

On his return to the UK in 1994 he took up he directorship of the Sleep Disorders Centre at St Thomas’s Hospital, was a founding member of the Sleep Section of the RSM and, in 2010, was awarded the UK’s first Chair in Sleep Medicine.

He currently practices at the London Sleep Centre in Harley Street, and has been a Sleep Advisor to Headspace.

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