You may have heard about blue light before, maybe in regards to technology and how staring at a screen for too long just before going to bed can impact your ability to fall asleep.
I remember first hearing about it a few years back, when my mum would say to me that I had to get off my phone or computer, or stop watching the TV just before going to bed because I wouldn’t be able to go to sleep, as my mind would be wide awake with thoughts racing through my head, and I’d end up lying there for hours trying to calm my mind down.
Who here has had a similar experience?
Light and sleep are tools that can be used to improve health dramatically (if you know how to use them correctly). However, not managing them properly are two of the biggest reasons for many health problems. Sound a little far-fetched? There are a lot of studies that have been done which support the idea that certain types of light, particularly blue light, have a significant impact on our circadian rhythms (which is our 24-hour internal body clock) and hormone balance in considerable ways.
What Is Blue Light?
Blue light is a colour on the visible light spectrum which our human eyes can pick up and see. Blue light has a short wavelength, which means it produces higher amounts of energy.
Before technology, the main source of blue light came from the sun! Now, we’ve brought blue light inside our homes in forms such as digital screens (like TVs, smartphones, computers, laptops, tablets, and gaming systems), electronic devices, and LED and fluorescent lighting.
Before 1879, when Thomas Edison patented the electric light bulb, artificial lighting didn’t exist. After sunset, people relied on candles, fires, and lanterns for their source of light.
After Edison’s incredible lightbulb creation, artificial lighting slowly became more and more common within households. However, it really skyrocketed within the last century as a result of the boom in technology where we’ve switched from using candlelight to mobile phone screens. It was only 30 years ago when a Harvard researcher discovered that light governs our internal clocks, and since then we’ve been slowly learning more about blue light.
As research continues, I believe more and more evidence will arise showing that interruptions in our natural circadian rhythms from artificial light will be partly to blame for many of the health problems we see in society today. Currently, it has been found that the excessive use of artificial light and the resulting lack of sleep may be linked to obesity, certain cancers, and an increased risk of heart disease.
Artificial lighting carries blue wavelengths of light that aren’t found in light sources like lanterns, candles, and fires. Blue light has been shown to improve alertness, mood and energy, and is quite important for overall health and wellbeing, but receiving it at the wrong times of the day can be harmful.
The Impact of Light on Circadian Rhythm
The body is extremely clever. It has systems in place that help regulate circadian rhythm. It relies heavily on outside input (especially from that of blue light) to signal times the body should be awake and times when it should be asleep. The eye contains about 30,000+ cells which are able to detect blue light. When they sense this light, they send signals to the brain to stop melatonin production. Melatonin is needed for sleep, and when it is suppressed at night instead of being increased, it can affect sleep quality.
Blue light wavelengths naturally occur in sunlight and can be seen during the brightest part of the day. These wavelengths are not found in other natural light sources, like fire, that would have been used at night before artificial light was created. If you’ve ever sat around a camp fire at night, you may have found it soothing and even felt a bit sleepy. This is largely due to its lack of blue light.
When it comes to blue light, it’s all about timing. Blue light during the day can be beneficial in many ways, such as:
- Promoting mood and alertness (it is possibly even better than coffee!)
- Signaling to the body to maintain healthy weight and adrenal function
- Sending the right signals to the brain for proper melatonin production.
These are crucial during the day. In fact, doctors have started using blue light therapy during certain times of the day to help improve sleep disorders, seasonal affective disorder (depression caused by lack of light) and other disorders.
Blue light becomes a problem when a person is repeatedly exposed to it in the evening after the sun has gone down, especially when this happens daily over a long periods of time. This interferes with the body’s natural rhythms and signals to the brain to reduce melatonin production, which is needed for sleep.
Sources of Blue Light Exposure
Most of us are exposed to much more blue light than we realise. Sources of this light include:
- Sunlight (the main source)
- Light bulbs and other sources of artificial lighting (LED bulbs are the main culprits).
- Electronics like phones, computers, tablets, TVs, etc.
Sunlight is a healthy source of natural blue light and it is beneficial to be exposed to blue light during the hours of the day that we can be exposed through the sun. It is impossible to receive improper blue light exposure from the sun, as blue light from the sun naturally signals correct circadian rhythms.
Now, due to artificial forms of blue light, we now receive blue light at times of the day where we are biologically ill-equipped to handle it, and this can affect our hormone levels and decreases sleep quality. Basically, artificial lights cause the body to believe that it’s daytime so the brain then suppresses the hormones required for sleep. This is excellent during the day but harmful at night.
Since recent studies have come out about the effect blue light from phones and screens has on our sleep quality, more people are now aware about not looking at a screen before going to bed, which is great. However further research has shown that indoor lightbulbs, particularly LED bulbs, may pose even more of a problem.
A paper written about the Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans found that being exposed to room light before going to bed suppressed melatonin production in 99% of individuals, as well as shortened the duration of melatonin production by around 90 minutes.
This is a huge difference and it is brought about simply from an exposure to normal room lighting. If our lightbulbs (especially LED bulbs) suppress melatonin in 99% of us, then no wonder we’re seeing a rise in disorders associated with abnormal functioning of the circadian rhythm.
What About Red Light?
While blue light is stimulating and suppresses melatonin production, red light does not have this effect and may not only be a good alternative, but may have its own benefits. You may have had the experience of a great night’s sleep while you’ve been out camping under the stars and sitting next to your campfire, or had a peaceful evening surrounded by candle light after experiencing a power outage. This lack of blue light and an exposure to red light may be why. What’s more, red light may also have benefits for hair, skin and joints as well.
As red light does not reduce melatonin levels like blue light does, it is a much better option to use as a light source at night. Blue light blocking glasses, which block out most blue light, are another alternative option for avoiding blue light at night. It helps address room lighting, as well as exposure to blue light from your phone, tablet, and computer.
How to Use Blue Light to Your Advantage
Timing your exposure to blue light throughout the day can make all the difference. Avoiding blue light altogether would be just as harmful (if not more so) to your health than blue light exposure at night. But understanding how light affects the circadian rhythm in the body enables us to use blue light to improve our health.
Actions Steps to Take to Harness the Benefits of Blue Light
- Blue light is essential during the day and it is important that you expose yourself to natural sources of it daily to aid in the proper functioning of the body’s natural circadian rhythms.
- As blue light suppresses melatonin at night, it’s a good idea to avoid blue light for 2 hours before going to bed. This can be done by avoiding screens and bright light in the home, and wearing blue light blocking glasses after sunset. TIP: this is a good, inexpensive pair of blue-light blocking glasses if you’re looking for one to use.
- Remove sources of artificial light (night lights, alarm clocks, lamps, etc.) in sleep areas.
As always, this is not personal medical advice and we recommend that you talk with your doctor.
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What are some of the ways you avoid blue light during the evening?
Have an amazing day!
What is Blue Light?. BluTech. Retrieved from http://blutechlenses.com/blog/blue-light/what-is-blue-light/
Wells, Katie. (January 11, 2018). Manipulating Blue Light to Improve Health. Wellness Mama. Retrieved from https://wellnessmama.com/91779/blue-light-improve-health/