Sleep

Sleep provides our body with an opportunity to rest, restore and rejuvenate and is a necessity that we need to function, along with air, water and food. But sleep is much much more . . .

We reflect on and resolve daily problems during sleep, as we rest, restore and deepen our wisdom through dreaming. Our dream state helps us heal and deepens our awareness of ourselves and others. The hours of sleep between 9pm and 1am are those which restore and refresh us the most and if we miss this window, no matter how much sleep we have it will not feel like enough.

Sleep also refreshes us for the day ahead. If we live in a way that honours the true purpose of sleep, it can become a sacred time each night that supports our evolution, back towards our soul and the oneness we are all from.

Sleep science emphasizes the importance of sleep to our mental and physical health. Our sleep-wake pattern is a central feature of human biology — we have a molecular clock inside our cells that keeps us in scinc with the sun.  The time is set by the rotation of the Earth, so that our bodies are perfectly aligned with day and night. This circadian rhythm helps us adapt to life on a spinning planet, with its endless wheel of day and night.

Circadian rhythms help determine our sleep patterns. The body’s master clock, is coordinated by a central, grandfather clock in the brain, which is called the suprachiasmatic nucleus (SCN for short). The SCN controls and synchronizes the whole body’s circadian rhythm and synchronizes all of our cellular clocks with the Earth’s rotation, through sunlight!

The SCN controls the production of  the hormone melatonin, that makes you sleepy. It receives information about incoming light from the optic nerves, which relay information from the eyes to the brain.

Sunlight is detected by special light-detecting cells, at the back of the eye, called ipRGCs. The ipRGCs send signals to the SCN in the brain. These signals are processed to coordinate the clocks within every cell in the body, so that they are synchronized with the light and dark cycle.

 
Figure 1 - Aligning our clocks to sunlight.
 
Picture taken from Frontiers for young minds.
 
The SCN using sunlight, can adjust the circadian rhythm to the gradual changes in daylight hours as we progress through the seasons. But sudden changes in the light and dark cycle can leave us feeling totally out of balance, which you may have experienced – it’s called jet lag. Since the invention of airplanes, we humans have been able to cross time zones in a matter of hours.
 
Travel in an airplane can leave us in bright daylight when our biological clock is preparing us for sleep. This can leave us feeling dizzy, drowsy and even sick. The symptoms of jet lag can last for several days, because the SCN takes time to align itself with the new time zone. Now that you know that the SCN uses light to adjust to the time of day, you would not be surprised to hear that the best cure, is to spend some time in the sun!

Artificial light interferes with our circadian rhythm and the world we live in takes light for granted and is awash with light  – our planet never sleeps! People who work at night must switch their sleep-wake cycles back and forth, and often go days without seeing any natural sunlight. 

Screen time with the LED screen, phones, computer and TVs eminate a huge amount of blue light. Blue is the color of light that ipRGCs are best at detecting. When this blue light comes from the sun it is a good thing, as our brains get the signal from ipRGCs that it’s daytime and time to stay awake. The SCN responds by inhibiting the production of the hormone melatonin, that makes us sleepy. When the sun sets, there is no more natural blue light around and so the hormone melatonin is produced, and we become sleepy.

But if you turn on an LED screen after dark, blue light will be detected by your ipRGCs, which cannot identify that the blue light is not from the sun. So, your brain gets the same signal, it is daytime and time to stay awake. The SCN tells the body to produce less melatonin and the level of melatonin falls. With little melatonin around, it can be very difficult to fall asleep, even at bedtime.

Try not to use electronic devices after dark, so you avoid confusing your circadian rhythm. If you can, leave all devices in a different room at night, as one night of sleep loss and circadian confusion can have serious effects on the body and mind.

Likewise, sugar, caffeine, chocolate, alcohol and other stimulating foods and drinks can make us feel racy, so that our body doesn’t settle and we stay up later then our natural bedtime.

Because this whole process occurs so seamlessly, we are not even aware of our biological clocks. But when our clocks are out of sync, we feel the effects almost immediately. Our modern world, with 24-h light, LED screens, and airplane travel and junk food can confuse our biological clocks. We should do what we can to help our clocks to keep time.

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