The science of sleep – life is a cycle

The science of sleep – life is a cycle

The science of sleep – life is a cycle


Have you ever noticed that when you go to bed late or don’t sleep so well that you feel out of sorts the next day? Could there be a science to sleep that offers us a way to live in harmony with ourselves and with the cycles of life?

We are designed to live life in cycles – in a rhythmic regular way – and our sleep is a great part of our daily cycle, which affects the greater cycle of the life we live.

The cycles of life are moving within us and all around us.

The inner workings of our body are cyclical – these are called circadian rhythms – and they are directed from within us, and influenced from without.

We live in a universe that is rhythmic and cyclical: the rhythm of night and day, as the earth spins on its axis; the periodic cycles of women, who cycle with the moon; the seasons of the year, as the Earth revolves around the Sun; the cycles of the Sun and our galaxy as they revolve around Sirius; and there are greater cycles than this. We are all in relation to each other, moving around and around each other, in a glorious cosmic dance.

We are designed to live and work in harmony with these universal cycles and when we do, our inner workings are rhythmic and harmonious too, for as it is above, so it is below – our bodies reflect the universal order of which we are each a unique and integral part.

Our inner cycles – circadian rhythms

Circadian rhythms are the regular physical, mental and behavioural changes in our bodies that follow our planet’s 24-hour cycle. They are found in most living things, including animals, plants and tiny microbes, and are designed to ensure that our internal processes are synchronised with our external environment.

They are regulated by a ‘master clock’ that consists of a group of nerve cells in the brain called the suprachiasmatic nucleus (SCN). This sits in the hypothalamus (our main physiological regulator), just above the optic chiasm, where the optic nerves from the eyes join and cross before passing back to the brain. This ‘biological clock’ drives our circadian rhythms, which are produced by natural factors within the body. Thus we are regulated from the inside, but we also respond to the outside environment, with light being the main cue influencing our circadian rhythms.

How do circadian rhythms relate to sleep?

Circadian rhythms are important in determining our sleep patterns. The body's master clock, or SCN, controls the production of melatonin, a hormone that makes us sleepy. Since it is located just above the optic nerves, which relay information from the eyes to the brain, the SCN receives information about incoming light. When there is less light – like at night – the SCN tells the brain to make more melatonin, so we feel sleepy.

Jet lag occurs when our circadian rhythms are disrupted. When we pass through different time zones, our body clock is different from the outside time. For example, if you ‘lose’ four hours of time when you fly, you wake up at 6 am and your body still thinks it’s 2 am, making you feel tired and disoriented. The body’s clock will reset itself, but this can take a few days.[i]

Circadian rhythms and human health

Mounting research evidence shows a significant impact of circadian rhythm disruption on human health. Shift work, chronic jet lag and sleep disturbances are associated with increased incidences of obesity, type 2 diabetes and dyslipidaemia.[i1]

Circadian disruption has also been linked to cardiovascular diseases, gastrointestinal diseases, and cancer.[ii, iii] And it has been shown to worsen diseases such as Parkinsonism.[iv]

The synchronisation of the external environment with the internal, and the central nervous system with the peripheral organs and tissues, allows our bodies to function with maximal efficiency. The daily light/dark cues caused by the rotation of the earth every 24 hours are the main agents that synchronise our biological clock to the external environment, but it can also be influenced by other cues such as social interaction, food or exercise.[ii]

These influences actually affect the clock genes themselves, showing how the external environment, and the way we are in it, can in fact influence our genetic expression.[ii]

Interestingly, studies have shown that the combination of a disruption in circadian rhythms and a diet high in sugar and processed fat is particularly prone to cause inflammation, now known to be an underlying cause of many diseases, including inflammatory bowel disease, heart disease and cancer.[v]

How does this influence the way we live?

Our bodies have a daily rhythm. They start to wind down in the evenings, around 5 pm, preparing us for sleep at 9 pm. If we honour this wind-down rhythm, we rest deeply and restore and regenerate our bodies, while the spleen clears us from the excesses of the day. We then wake in the early hours, ready to live another day, for which the body gives us kidney energy from 5 am to 5 pm, until it starts to wind down again in preparation for the repose of the night.

Living in accordance with this rhythm is deeply nurturing and supportive, of our human bodies and of our evolution as human beings.

But we think we are smart, clever and know better than the universe.

We think we can get more out of the day by staying up late, stimulating ourselves with food, drink and entertainment in its many forms. When we feel the hangover effects of this the next day, we think we can override them with coffee, sugar and other forms of stimulation. And when our bodies finally break down and get sick we seem surprised, overriding this big signpost to rest with painkillers, cold and flu tablets, and the like. We push on regardless, and then when we finally get a serious illness like cancer, we ask – how could this happen to me?

True health – a rhythmic way of life

How can we return to a truer way of living, one that is synchronised with the internal rhythm of our body and the external rhythm of nature and the universe in which we live?

Most of us have natural dips in our energy levels through the day, most commonly between 1 and 3 pm (the post-lunch crash) and between 2 and 4 am, but this can vary from person to person. Some people feel more vital and energetic in the mornings, and some in the evenings. But this is largely influenced by the choices we make in how we live the day.

If we follow our body’s natural cues regarding when to go to sleep and when to wake up, our body clock ticks over nicely, and our circadian rhythm stays balanced. But if we change our schedule, by staying up late or sleeping in, by eating certain types of food, or spending hours on screens, this can disrupt our body clock.

There are some things we can do to help maintain a healthy circadian rhythm:

1. Maintain a consistent sleep schedule.

A regular bedtime is part of this, but so is waking up at the same time every day. It may be tempting to sleep in on the weekends, but doing this can throw off your body clock during the week.

2. Go for a morning walk.

In the morning, a stroll in the sun will give you an energy boost and reset your circadian rhythm. If you cannot walk outside, at least open the curtains to let the light in, or turn on your brightest indoor light.

3. Wind down in the evening.

Bright lights in the evenings can throw off your body clock by making your brain think it is still daytime. Artificial blue light (the type that laptops, tablets and phones emit) is the most potent, so try to power down tech devices at least an hour (and preferably two or three hours) before bed. [vi] This gives us an opportunity to truly wind down; to reflect on our day and how it was for us, to deal with anything that was left unresolved, so that at the end of the day we feel settled and complete, and able to rest in preparation for another day.

4. Eat and drink in a way that supports your rhythm.

As it has been shown that diets high in processed fat and sugar aggravate the effect of circadian rhythm disruption on the body[v], it makes sense to consider that not eating these foods will support our daily rhythm. What we eat can greatly influence our energy levels, and may help to stabilise our daily rhythm, or make the swings more pronounced. If we eat carbs at lunchtime, the post-prandial snooze is almost inevitable, and if we are at work, we then need to prop ourselves up with coffee, which causes our blood sugar levels to drop, so then we need more sugar, which makes us racy, and so we go, up and down. And if we add alcohol to the mix in the evenings, this can interfere with our sleep even more.

5. Honour the way we live.

We live life in cycles, and the way we live a day affects the way we sleep at night, which influences how we are the next day, which then affects the quality of our sleep the next night… We don’t leave any of it behind… we carry it all with us, in this body of ours, everywhere we go.

We are just living one day, over and over again, in a rhythmic, cyclical way, until we learn to live in harmony with ourselves, and with everyone and everything around us –– in this grand and wondrous cyclical universe we live in.

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  • [i]

  • [ii]

  • [iii] Organ disease

  • [iv]

    4. Parkinson’s disease

  • [v] Inflammation

  • [vi]

Filed under

ExhaustionFatigueInsomniaSleepTime managementTiredness

  • By Dr Anne Malatt, MBBS, MS, FRACS, FRANZCO Eye surgeon, wife, grandmother

    A woman with a wealth of worldly experience and a richness of lived wisdom, I live and work in a country town, love my work and the people I work with, and enjoy time with my family and friends, walking, reading and writing.

  • Photography: James Tolich