Key Takeaways...
Question: Does red light help you sleep?
Short Answer: Yes, kind of…
It’s not really that red light helps you sleep, it’s that red light is devoid of the blue wavelengths of light which prevent the body from releasing melatonin.
Melatonin helps you set your circadian rhythm and naturally make you tired after the sun sets. I’ve heard many people online say that they’ve tried melatonin before and it doesn’t do any good. Most likely they’re doing it all wrong.
If you’re taking melatonin you need to know that there’s a certain way you need to take melatonin which I go into detail here.
Combing a light environment utilizing low amplitude red light, along with getting morning sun and taking melatonin when the sun goes down is a powerful trifecta to help you sleep.
On the other hand, red light therapy has been all the rage for the past 10 years now. Red light therapy is also called low level laser therapy (LLLT) or photobiomodulation. Back in 2012 I heard a lecture by Dr. Jack Kruse on how light affects our biology. It really changed my understanding of how light impacts our sleep and health.
I’m assuming that when you searched about how red light impacts sleep you’re wanting to know how ambient lighting affects sleep and not necessarily red light therapy.
An important note is that red light therapy uses a high intensity light, so I don’t even recommend doing that after sunset. Surprisingly there have been a couple studies showing how even high intensity red light could suppress melatonin.
This article is about the ambient indoor lighting in your home or bedroom and its impact on insomnia and other sleep conditions.
“Dim light at night (LAN)-induced melatonin suppression disrupts this circadian-regulated host/cancer balance among several important cancer preventative signaling mechanisms, leading to hyperglycemia and hyperinsulinemia in the host and runaway aerobic glycolysis, lipid signaling and proliferative activity in the tumor.” – Source
Back to Dr. Jack Kruse and his work on light.
He talked about the color of light and how that impacts our circadian rhythms, hormone secretions, cellular functions, detoxification and melatonin levels. Melatonin is our golden hormone. We need to do everything we can to protect it.
At that point I was eating a more Paleo type diet and I thought that your health was determined by the food you eat, not necessarily the light you live under.
I couldn’t have been more wrong.
There are now thousands of studies showing how man made light like fluorescent light and LED lights alter circadian rhythms, suppress melatonin, increase oxidation & inflammation, cause diseases like skin cancer and diabetes. Last but not least there are even studies showing that artificial light at night causes sleep disruptions like insomnia.
The main idea about red light and sleep that hit home was how light directly impacts melatonin. When you understand that melatonin is the most powerful antioxidant and anti cancer hormone you make, you realize melatonin isn’t just a sleep hormone. It’s a repair hormone. Because melatonin helps prevent cancer and blue light from technology shuts down melatonin, could you say that blue light causes cancer?
My argument is a resounding yes.
Regardless we need to be aware of the light we live under if we want to optimize our sleep.
The Science of Light & Circadian Rhythms
On our skin, in our gut and in our eyes we have what’s called photoreceptors. These are photopigments that receive photons of light from our environment. Photoreceptors have different names depending on where they are on or in the body. The photoreceptors we have in our eyes are called melanopsin. In our skin we have neuropsin (OPN5) and encephalopsin (OPN3) aka panopsin.
Melanopsin is a photopigment found in the intrinsically photosensitive retinal ganglion cells (ipRGCs). This isn’t just another molecule; it’s a game-changer for your circadian rhythm and overall health. Melanopsin absorbs blue light, particularly around 480 nm wavelength.
Melanopsin-containing cells, specifically the intrinsically photosensitive retinal ganglion cells (ipRGCs), are found in your retina. That’s the light-sensitive layer at the back of your eyeball.
All man made light contains blue light with no yellow, orange or red frequencies like the sun does. This is terrible for your hormones, longevity and sleep. 3 things you probably want to optimize.
When any light hits these photoreceptors they impact your mitochondria and send circadian timing signals to your suprachiasmatic nucleus (the master clock in the human body located in the hypothalamus in your brain).
Now inside your eyes there are rods and cones to detect wavelengths of light. The rods are your night vision specialists as they don’t detect color in as much as detect and help with low light conditions.
The cones in your eye can be broken down as follows:
- Cones – There are three types, each sensitive to different wavelengths of light. They give you color vision and work best in bright light.
- L-cones – Long-wavelength (red light)
- M-cones – Medium-wavelength (green light)
- S-cones – Short-wavelength (blue light)
Why Blue Light Keeps You Awake
People don’t understand how powerful a signal light is on our health. Most CBT-I practitioners and sleep coaches will tell you to simply avoid screen time 30 minutes before bed. When they say such things, I know right way that they’ve never really read any research papers on how light impacts hormones like melatonin and cortisol. This under expression of melatonin and over expression of cortisol creates oxidative stress and prevents sleep.
For example, let’s say you turn off your computer screen or stop using your cell phone 30 minutes before bed. But your house has fluorescent or LED lighting on, that light coming into your eyes and on your skin is still going to suppress melatonin secretion for up to 4 hours. So yes it’s good you stopped looking at a screen but what kind of ambient lighting is in the home or bedroom you live in?
“…blue-enriched (460–495 nm) light in the evening (during the 3 hours before bedtime) disrupts nocturnal sleep, phase delays the circadian system and disrupts circadian rhythms more than blue-depleted light at the same intensity.” – Source
All light matters.
This is why I recommend using proper bulbs in your home that contain orange and red wavelengths. Here’s a picture of our home from the backyard.
I also hear sleep coaches recommend turning off your phone and laptop 30 minutes before bed, but that isn’t enough. It needs to be at least 4 hours before you go to sleep.
There are tricks you can utilize like running a certain kind of software that allows you to remove all blue from your computer. There are even computers that are now made that have no blue light in them.
Blue light around 480 nanometers keeps you awake by activating melanopsin activity in the ipRGCs. This then sends a strong signal through the retinohypothalamic tract directly to the suprachiasmatic nucleus which again is your master clock. This frequency of light is going to tell the master clock to tell all the other clocks in the body to halt the secretion of melatonin into the blood. At the same time, cortisol from your adrenal glands will rise (like its supposed to in the morning in response to sunlight) increasing oxidative stress and keeping you awake and alert.
Regular exposure to blue light in the evening can shift your sleep phase, making it harder to fall asleep at your desired time. This used to be me. I’d be working in a data center under florescent and LED lights until midnight. I couldn’t figure out why I couldn’t sleep until 3am.
The Many Nuances of Light
Not all light is the same. Essentially we want to mimic the sun as best as possible. This means the brightest man made light we should be exposed to is around 12 or 1pm. This is because that’s the exact time that the sun over head is the brightest. In an ideal world, when the sun has set, we don’t want any man made light hitting our skin or entering our eyes at all, even if it’s red light.
The most natural light we should be exposed to is perhaps 2 hours of candle light or firelight after sunset, then total darkness.
That’s not completely practical but the ideal is to mimic nature and how we’re biologically made and have lived since the beginning of time. When the light bulb was invented in 1879 and we started living in electrical grids around 1920 to 1930, that’s when all of our health conditions started.
Prior to the invention of electricity, we were much more healthier and people didn’t have a problem sleeping like we do now.
Yes red light helps with sleep but only as much as it doesn’t suppress melatonin. But the red wavelength of light isn’t magical in the sense that it promotes sleep. It just doesn’t cause sleep issues like insomnia that blue light does.
Remember to mimic nature. Embrace bright days and make your evenings dark. If you have to have lights on at night, consider getting red light bulbs. If you live with somebody that doesn’t want to have a red lit home (I get it, this concept isn’t easy to accept), then you can still install software on your own computer or cell phone that turns off the blue light. You can also wear blue blocking glasses if your partner wants to live under LEDs.
Mimic nature and enjoy better sleep.
Color Temperature
Color temperature really just refers to the hue of light, which is measured in Kelvins (K). Daylight, which has a high color temperature (5000K-6500K), is extremely abundant in blue wavelengths and signals your brain to stay alert. In contrast, light with a lower color temperature (2000K-3000K), like candlelight or incandescent bulbs, has less blue light and is more conducive to relaxation and sleep. I set the color temperature of my Iris computer software to 1800 kelvin during the day and 0 kelvin after sunset. Exposure to high color temperature light in the evening disrupts melatonin production and can interfere with your circadian rhythm, making it harder to fall asleep. This goes for any light you’re exposed to.
Irradiance
Irradiance is the measure of the power of light received per unit area, typically expressed in watts per square meter (W/m²). Higher irradiance means more intense light exposure, which can significantly impact your circadian rhythm and alertness levels. During the day, high irradiance from sunlight helps regulate your internal clock, promoting wakefulness and proper timing of physiological processes. However, exposure to high irradiance light in the evening can suppress melatonin production,
Duration
Extended exposure to blue light, especially in the evening, can significantly suppress melatonin production. The longer you’re exposed to blue light, the greater the disruption to your circadian rhythm, making it harder to fall asleep and achieve restful sleep. To maintain healthy sleep patterns, it’s crucial to limit blue light exposure in the hours leading up to bedtime. I recommend zero blue light after sunset. That’s the way nature does it.
Timing
As I’ve discussed in this article, the timing of blue light exposure is crucial for maintaining a healthy circadian rhythm. Blue light from the sun during the day is natural and normal. It boosts alertness and mood, aligning your internal clock with the natural day-night cycle. But, exposure to blue light in the evening (after sunset) disrupts melatonin production and interferes with sleep. To avoid this, minimize blue light exposure at least 2 to 3 hours before bed to ensure your body can naturally wind down and prepare for sleep.
Conclusion
So yes, red light does help you sleep. But only in so much as it doesn’t keep you awake like blue light does. Blue light in all its forms should be avoided after sunset. Get regular sunlight on your body and in your eyes (without burning) during the day while grounded, and embrace the darkness of night.
This will put your body in alignment with nature’s daily cycles and even seasonal cycles.
I’ve found that by using dim red lights in our home, getting more sunlight and blocking blue light (during the day and night) while taking melatonin has been the foundation of my sleep. I do many other things as well but doing those things has really changed my sleep quality over the years.
The “side effects” to doing those things will be having more energy, feeling rested when you wake up, having more drive in life, less depression, better sex drive and hormone levels, longer life, disease prevention and more.
Questions:
- Do you currently use red lights in your home?
- Would your partner be on board or not?
- Does it make more sense how avoiding screen time 30 minutes before bed is too basic?
- Do you block blue light during the day?
