Light & Sleep

Located just behind the bridge of the nose is a tiny region of the brain in the hypothalamus called the suprachiasmatic nucleus or (SCN). The SCN serves as the central control room for all our biological clocks; it oversees all of the body's time-activated processes.

When a light stimulus hits the retina of the eye a signal travels to the SCN and then onward to the brain's pineal gland, the gland responsible for the production of melatonin. This interaction between the SCN and pineal gland, affects our sleep cycle and other functions that show circadian rhythmicity like: physical activity, alertness, hormone levels, body temperature, immune function, and digestive activity. The SCN coordinates these rhythms across the entire body and in addition it regulates gene expression in specific tissues.

Sleep is essential for our health. It gives the brain time to brain repair, restock, and reenergize. It is during sleep that debris from the daily brain functions and activities is cleaned up. There is a layer of piping that surrounds the brain’s existing blood vessels called the glymphatic system. During sleep the space between brain cells increase this allows the brain via the glymphatic system, to flush-out debris and toxins that build up during waking hours. Without sleep debris piles up and actually damages the brain.

Therefore sleep is essential to regulate the circadian rhythm; the time clock of the body and to allow clean up from the daily activities as well as a time to consolidate memories and reflect upon what the brain learned that day.

Quality sleep is essential to brain health!

Our circadian cycles regulate our energy levels, performance, metabolism and our recovery. Regular exposure to cycles of natural light is required to synchronize these circadian rhythms. Unfortunately most of us don’t get enough natural light during the day and get too much artificial light at night. Studies show that artificial light at night disrupts our circadian rhythms and thereby increases the risk of insomnia, depression, cancer, diabetes, and cardiovascular disease.

Sleep deprivation can alter the function of up to 711 genes, including some involved in stress, inflammation, immunity and metabolism. We depend on genes to produce a constant supply of proteins for replacing or repairing damaged tissues and they stop working after just a week of poor sleep. Insomnia alters the function of the immune system and impedes the metabolism and absorption of nutrients. A lack of sleep affects your ability to heal!

Emergent research confirms that our sleep habits have a direct impact on the composition of our gut bacterial colonies. When we don’t get enough rest, the health and diversity of our microbiome suffers.

Scientists even suggest that the microbiome is the link between sleep deprivation and mental decline. When we don’t get enough sleep, imbalance in our guts causes inflammation in the brain which manifests as anxiety and depression and contributes to the eventual development of dementia and Alzheimer’s.

Get quality light and sleep!

Key Points

Sunlight is essential to set our biological clocks.
Our biological clocks run on a 24 hour cycle called a Circadian Rhythm. The sleep-wake cycle is the most important and well-known circadian rhythm, but the body has other time-activated processes like physical activity, alertness and hormone levels. And every cell in the body has its very own biological clock.
Light stimulus passes the retina of the eye and a signal travels onward to the suprachiasmatic nucleus (SCN) and the pineal gland in the brain. The light input to the SCN synchronizes all the biological clocks in the body. And light stimulus to the pineal gland stimulates it to produce and release our sleep hormone melatonin.
Throughout evolution the light stimulus has been the natural changing light intensities of sunlight.
Today we are bombarded with artificial light, particularly at night. Artificial light from computer and phone screens and from LED lights contains blue light. Natural night time light only has red light that fades to complete darkness.
Exposure to cycles of natural light and darkness regulates hormone production and release. Morning sunlight activates production, mid-day blue light stops production and evening darkness stimulates the release of hormones. Prolonged blue light exposure can affect hormone production.
Artificial light exposure at night disrupts our circadian rhythms and thereby increases our risk of insomnia, depression, cancer, diabetes and cardiovascular disease.
Sleep deprivation alters the function of our genes and has a direct negative impact on the composition of our gut bacterial colonies, which has an impact on brain inflammation.
While we sleep the glymphatic system in the brain flushes out debris and toxins that build up during our waking hours. If we do not sleep, debris and toxins pile up and damage our brain.

Action Steps

Manage your circadian rhythms by trying to expose your eyes to changing natural light intensities. You might have to wake earlier and step outside to watch the sunrise. Get outside at lunch time so your eyes are exposed to natural blue light. At night time limit as much exposure to artificial blue light as you can. This is especially important if you are having a difficult time falling asleep.

At night turn off as many LED lights as you can. Consider using candlelight as that is natural red light. Limit your use of computer screens and cell phones that emit blue light. You can mitigate blue light exposure from you computer by downloading an App called f.lux. This app changes the light intensity on your computer screen. It warms up your screen at night to help you relax and wind down before bed.
https://justgetflux.com/

You can also change your iPhone screen to red at night by triple-clicking the Home Button. Follow the instructions on the link below.

Red light is a healing frequency of light and when used correctly could provide health benefits. Red light stimulates the production of collagen; it can help with joint pain and aid in muscle recovery. The frequencies of light with the most proven benefits are 660 nm visible red light and 850 nm invisible infrared light. These are the two frequencies to look out for when purchasing a red-light therapy device. Red light also has the ability to stimulate ATP production and ATP is energy! For further information click on the link below.

Consider purchasing blue light blocking glasses. Make sure you get quality glasses that truly block the short wavelengths of 400 nm to 500 nm of blue/green light. Check out this website that have quality glasses.

https://www.blublox.com/

These glasses are great to use if you are on the computer at night or if you like to read with your ipad.

TV screens emit blue light but because you generally sit a fair distance from the screen that helps mitigate exposure. This is not the case if you are watching movies on your laptop at night! Blue light blocking glasses would be beneficial in this situation as you are so close to the screen.

You need to make sleep a priority! The best way to set your circadian rhythms is to practice good sleep hygiene. Good sleep hygiene is all about putting yourself in the best position to sleep well each and every night. For tips on how to improve your sleep hygiene check out the link below.

It is a misconception that being a morning or evening person is a “choice”. It's our genes that predetermine whether we'll be early birds or night owls. We can tweak our natural programming, but not by more than two hours in either direction. Everyone’s circadian rhythm is slightly different.

Dr Michael Breus is a clinical psychologist and a sleep expert. He has taken circadian rhythms one step further. He has come up with four classifications called sleep chronotypes. Based on morning and evening preferences, he identified four different chronotypes, or circadian rhythm personalities, and then associated each one with an animal whose sleep-wake habits best mirrored them.

When Dr Breus switched up his patients’ daily routines to accommodate their sleep chronotype, their productivity soared and several sleep issues resolved.

Understanding your particular sleep chronotype could help you figure out the best time of day to make an important decision, work out, and do anything better.

It’s easy to learn your chronotype by taking this quiz: www.chronoquiz.com.

For more information from Dr Breus Phd checkout his website. He is also a good resource for sleep supplement information.

https://thesleepdoctor.com/

BodyCheck Prevention & Health Physical Therapy Centre

Light & Sleep

Exposure to natural light and sleep are essential for good health.

Visible Light Spectrum

Glasses block out the blue light spectrum.

Blue Light Blocking Glasses

Blue Light Blocking Glasses

Glasses block out the blue light spectrum.

Blue Light Blocking Glasses

Glasses block out the blue light spectrum.

Glasses block out the blue light spectrum.

Glasses block out the blue light spectrum.

Key Points

Action Steps