What’s Light Got To Do With Sleep? Everything.
We are literally hardwired for sleep right down to our very genes – the instructions for life itself!
In 2017, a group of scientists won the 2017 Nobel Prize in Physiology or Medicine for the discovery of a gene that serves as a type of biological clock. With exquisite precision this biological clock adapts our physiology to different phases in the day, regulating functions such as hormone levels, metabolism and behaviour.
This gene encodes for a protein that builds up in the cell during the night and breaks down during the day, and with it, conducts the rhythm of life within the living organism.
Light – The Sun – Affects The Biological Clock
Our health is affected when there is a mismatch between our external environment (i.e. daylight and darkness) and this internal biological clock. Hence why jet lag is so keenly felt and why a chronic misalignment between our lifestyle and our biological rhythm is associated with disease.
The activities and behaviours of humans, plants and animals are based on their relationship with the sun. As Nobel prize winner Sir Paul Nurse told the Guardian:
The Biological Clock Is Key To Good Health
Our internal circadian rhythm conducts an ebb and flow of endocrine and immunological processes and it appears that if we flow with it, we protect our health from all host of diseases from obesity to cancer and even mental health disorders.
This internal clock, as set by this gene would explain why shift-workers have a higher rate of cancer and why weekend lie-ins don’t seem to entirely fix the problem of “sleep debt”.
Don’t Ignore The 9pm Sleep Signals
The 21st century presents a problem of rhythm like no other before. The line between work and home is blurred for many people, the temptation to scroll through screens and catch up on missed episodes all at once put the person, sometimes unconsciously out of sync with their natural biological rhythms, often pushing through their most sleepy time around 9pm and getting a “second wind” as it is so commonly described. But my view on this is that they have simply gone past when their body naturally wants them to sleep and are now in a higher state of alertness due to stress hormones. This adaptive response disrupts one of the most healing hormones of your body, melatonin, and with it sleep.
To learn more about this fascinating discovery, read here.
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