A circadian rhythm is a natural, internal process that regulates the sleep-wake cycle and repeats on each rotation of the Earth roughly every 24 hours. It can refer to any biological process that displays an endogenous, entrainable oscillation of about 24 hours.
Harmonizing with nature - maximizing exposure to natural light and hacking artificial light.
Your body is run by a master clock called the SCN which runs all other body clocks. When your body clocks get the wrong light signals or light signals at the wrong time, disruption occurs and that is detrimental to your physiology.
What is Blue Light Toxicity?
Sunlight is full light spectrum and contains all colors (wavelengths), including blue - however -blue predominates during the middle of the day - giving the body the signal to forage and mate and be active - in the morning and evening there is less blue.
1. Technology has a predominance of blue light as it is more economical to produce
We therefore have more blue light at all times during the day when we use technology (any screen at all)
2. Timing of blue light exposure - using technology after the sun goes down is especially damaging
3. Blue light blocker sunglasses filter out the blue wavelengths of light and can be used after sunset if you’re looking screens late in the day
4. Red light is protective against blue light exposure - so getting sun early in the day, or using a red light therapy device can protect you against blue light damage.
Circadian Biology
The 2017 Nobel prize for medicine was awarded for the discovery of how our circadian rhythms are controlled. Our circadian rhythms are regulated through light-sensing mechanisms within our eyes. Alongside the rods and cones in our eyes we have a small amount of innately photosensitive cells. These cells are designed to not help us see, but rather sense light as part of our circadian management system.When these specific retinal cells sense light, they produce melanopsin, which directly tells certain parts of our brain to stay awake and alert. As well as suppressing melatonin, melanopsin has been found to help regulate and set our body's circadian rhythm.
What are biological clocks?
Biological clocks are organisms’ natural timing devices, regulating the cycle of circadian rhythms. They’re composed of specific molecules (proteins) that interact with cells throughout the body. Nearly every tissue and organ contains biological clocks. Researchers have identified similar genes in people, fruit flies, mice, plants, fungi, and several other organisms that make the clocks’ molecular components.
What is the master clock?
A master clock in the brain coordinates all the biological clocks in a living thing, keeping the clocks in sync. In vertebrate animals, including humans, the master clock is a group of about 20,000 nerve cells (neurons) that form a structure called the suprachiasmatic nucleus, or SCN. The SCN is in a part of the brain called the hypothalamus and receives direct input from the eyesSleep hacks
Track your sleep - Sarah uses an Oura ring - look for REM, Deep sleep in particular
Make time for recovery in your day
Have some tech free time before bed - at least an hour
Don’t eat late at night
Get rid of ALAN (artificial light at night)
Use amber light in the evening - candle light is good - Himalyan salt lamps are good
Melatonin is the hormone of darkness - see sunrise in the morning
Magnesium salt baths
Lavender essential oils can help
Use blue blocker glasses
References: