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Why Your Relationship With Light Matters...

How light controls our health

Humans are essentially solar powered creatures, so it's vital that we understand the role that the sun, and specifically the light that it provides, plays in regulating our circadian rhythm, sleep and overall health.

Your circadian rhythm is the 24-hour biological clock that is built-in deep in your brain, affecting every system of your body and mind.

Your circadian rhythm influences your hunger, digestion, metabolism, energy levels, alertness, core body temperature, mood, the function and production of many key neurotransmitters, hormones and, most crucially, sleep.

Your circadian rhythm is the hidden engine that is running your personal health show in the background of your life, and NOBODY is talking about this in conventional healthcare! This is the missing piece of the health puzzle for many of us.

Light controls your circadian rhythm, and this affects every area of your health including your energy, mood, libido, body weight, sleep, digestion and more…

You NEED to understand how light impacts your circadian engine to be healthy.

At a fundamental level, our interaction with light is governed by the laws of nature.

If we obey our evolutionary principles and interact with light in the right way, we are able to unlock high-quality sleep, happiness, energy, motivation and radiant health.

If we choose to disobey nature’s laws, we can expect to suffer the physical, mental, emotional and spiritual consequences.

What's coming up next is some of the most important information you need to know and act upon to ensure health and happiness for yourself and your family.

For 99.9% of our time on this planet as a species, our sleep and circadian rhythm were controlled by the light in our natural environment. In no other period of time has human health declined so rapidly as the previous century, where our relationship to day and night has changed so much due to electricity, increasingly brighter light bulbs and digital technology (none of which are bad when used appropriately).

To understand the significance of light and darkness for our sleep and health, we need to understand how our ancestors interacted with light and marry this understanding with the latest advances in science and technology in order to protect and enhance our sleep, mood, performance and overall health.

Mastering your health begins with mastering your light exposure.

Why our body needs natural morning light

Every day our ancestors’ circadian rhythms were primed by exposure to natural light from the morning sun.

When our bodies come into contact with morning light, this cue is received by our eyes and skin, which then send signals to our brain and all of our corresponding organs and glands, bringing energy, alertness and vitality.

Natural morning light is also crucial for producing brain chemicals such as serotonin (our happiness neurotransmitter), dopamine (our motivation neurotransmitter) and endorphins (other natural feel-good chemicals) that impact our energy levels, mood, drive, attention, focus, pain and sleep. Without the correct daily exposure to natural light, all of these areas of your health suffer.

The message that natural light sends to your brain is “wake up, it’s day time”.

Natural light infographic

intensity and wavelength

(This photo shows the full wavelength spectrum of light given off by daytime sunlight.)

When you begin to expose yourself to more natural light throughout the morning and daytime, you are halfway toward a healthy circadian rhythm and high quality sleep. This is one of the two most important daily steps that you can take to improve your health!

Why darkness makes us healthy and happy

For millions of years, as the sun disappeared each evening, this served as the vital environmental cue that directed our brains to wind down and produce large amounts of our KEY sleep hormone, melatonin.

Melatonin is the hormone that creates the condition for your body to experience high-quality sleep. It also affects the function of virtually ALL of the other hormones and many brain chemicals, including those related to losing weight, mood, appetite, digestion, metabolism, immune system function, muscle growth, libido, and much more…

I cannot emphasise enough how important it is that your body’s melatonin system works well. If you want to sleep better and ‘live your best life’ then you really need to pay attention to the information coming up!

Every single night our evolutionary biology expects that the sun will set and the brightness and intensity of light in our environment will slowly decrease into almost total darkness as it has been in our natural outdoor environment for millions of years.

As this process occurs over the course of each evening, our brain’s pineal gland begins to release large amounts of melatonin that sets us up for an optimal state of highly regenerative deep and restful sleep.

Contrary to morning and afternoon sunlight which wakes us up, the frequency and wavelengths of light given off by the sun at sunset provide a signal to our biology to begin to wind down and prepare for sleep.Once the sun has set this removes ALL forms of BLUE and GREEN light from our environment (these colours are found in daytime light which wakes us up).

In our modern society, brightly lit LED light bulbs and technology devices such as televisions, mobile phones, laptops, iPads, tablets and other equipment contain huge amounts of blue and green light, and they are becoming faster, brighter and more connective than ever before. This is only likely to continue into the future.

While these devices aren't the devil, if you don't consider the way we interact with the blue and green light that they give off in the evening, they will destroy your health.

light graph

(This photo shows the unnatural wavelengths of light given off by LED lighting contained within mobile phones, televisions, laptops and other artificially-lit technology devices)

The amount of melatonin that we are able to produce at night time is directly proportional to the quality of our sleep, our mood and overall health.

More night time melatonin = a longer and happier life.

How exposure to artificial light at night is destroying our health

Let’s leave the campfire and head to the city… fast forward to the 21st century.

“Houston, we have a problem.”

Two inventions changed the world forever: Thomas Edison’s first power-plants that granted access to constant electricity, and the humble light bulb.

These technologies have arguably resulted in the most miraculous achievements of our civilisation to date, and, less often considered, they have also caused much of the hidden and misunderstood decline in our everyday physical and mental health.

Even the world’s biggest technology companies such as Apple are catching on.

Why do you think that they have now implemented the Night Shift Mode to mildly alter the blue light given off by their devices in the evening?

It was after Harvard University researchers discovered that exposure to artificial blue and green light at night throws our hormones and circadian rhythm out of sync.

• Blue and green light exposure after sunset stimulates the stress hormone cortisol. This keeps us awake and alert, stopping our body from recovering fully.

• Blue and green light after sunset tells your body it's day time, suppressing your melatonin production, delaying your bed time and altering your rhythm.

• This can lower melatonin by up to 60%.

Science has shown us that lower melatonin production interrupts nearly all of the hormones in our body. Not only does this result in terrible quality sleep and reduced recovery, but it also increases your risk of anxiety, depression, cancer, obesity, autoimmune conditions, diabetes, heart disease, infertility and other diseases.

Thankfully, it's been discovered that not all colours of light have the same effect. The most damaging for our sleep are blue and green wavelengths. This means that with some smart thinking and a few changes, we are able to filter out the dangerous types of light at night and replace them with sleep-friendly lighting that doesn't ruin health.

melatonin-blocking wavelengths


This info is just the tip of the iceberg when it come to protecting your sleep and overall health. Here are the key points from this article that you should remember:

• Light is the master of our circadian rhythm, and therefore the master of our sleep.

• As our circadian biology rules our overall health, the correct day time and evening light exposure is crucial for good health.

• The sun provides the natural spectrum of light that we need to coordinate the production of serotonin, cortisol, melatonin and many other vital hormones that ensure our circadian rhythm functions well.

• Artificial light after sunset reduces our body’s ability to produce melatonin and the quality of our rest and recovery.

•To put this in the most simple terms, exposing yourself to more natural light during the day and less artificial light at night are the key ingredients for a healthy circadian rhythm, high-quality sleep, happiness and good health.

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