I just want to start this stop by saying, Light is freaking cool. I’m not going to pretend to know everything there is to know about the full spectrum of light and how it affects our health. In fact, I think there are very few that understand it to the full extent of what is becoming known by science. But I find it completely cool and fascinating.
Here is what I do know. Our bodies have a natural rhythm to them, called circadian rhythms. These rhythms are important in determining sleeping and feeding patterns and this cycle links to brain wave activity, hormone production, cell regeneration and other biological activities.(1) In short it’s important to maintaining a healthy sleep pattern and our health in general.
Why Is Sleep So Important?
During our sleep we consolidate memories. We recover, we heal. Lack of sleep is a detrimental barrier to health, performance, mood and memory. It plays a pivotal role in the normal function of the endocrine (including pituitary glands) and immune systems. Lack of sleep is linked to health problems including obesity, diabetes, heart disease, kidney disease, and depression. Sleep helps maintain a healthy balance of hormones such as leptin (your hunger hormone) and insulin (your blood sugar hormone that is vital to optimal energy production), which is why a lack of it is linked to obesity and diabetes, and low energy. A good night’s sleep improves learning and memory, mood, decision making and problem solving. Not to mention, as a kid, sleep is when you do your most growing, and is thus even more vitally important in the early years. (5)
Circadian Rhythms and Our Health
So back to circadian rhythms. These rhythms are found in most living things and respond to light/darkness cycles in a being’s environment.
They are controlled by the body’s master clock. This master clock is located in the hypothalamus, and consists of a large group of nerve cells (about 20,000) in the brain called the suprachiasmatic nucleus, or SCN. The hypothalamus is located in the brain just above where the optic nerves from the eyes cross. (2) And that location is important.
Circadian rhythms are produced by the body, but they are affected by signals in the environment, mainly the light and dark cues.
98% of sunlight enters the body through the eyes. (3) And with the location of the SCN being just above the optic nerves, is it all that surprising light plays such a huge role in controlling the rhythms. The SCN relays information about light coming through to the brain.
Truly the number one way to get a consistent good night’s rest is to reset your internal clock. To do this you have to be wary of light exposure.
Blue light messes with your internal clock and the production of melatonin. Exposure to bright blue lights in the evening can turn off your melatonin production that is going to help you fall asleep. Further getting out into the sunlight or the bright lights of your kitchen, etc. first thing in the morning wakes you right up, and actually helps nighttime melatonin production occur sooner. (4) So we want bright morning light in the morning ideally from the sun. The melatonin rhythm phase advancement caused by exposure to bright morning light has been effective against insomnia, premenstrual syndrome, and seasonal affective disorder (SAD).
So here’s the hot tip for resetting your internal clock:
- Eat your breakfast outside whenever possible. Poor weather isn’t a great excuse. Really poor weather, well ok.
- Even if it’s cloudy or rainy you’ll still get the blue light from the sun coming through.
- And certainly don’t put on sunglasses during this time.
The Woes of Blue Light Especially at Night
However at night, we need less light, and specifically less blue light in order to make more melatonin. Unfortunately all our favorite tech devices (ipads, tvs, cellphones) have blue light coming from their screens. But not just our tech devices. CFL light bulbs are heavy on the blue light spectrum.
While natural blue light is good for us especially in the morning and early day, at night time blue light can affect our circadian rhythms. Further artificial blue light from staring at our screens all day can affect our eye health. Blue light has a tendency to flicker due to its short wavelengths. This flickering can cause glare and contribute to eyestrain, headaches, and physical and mental fatigue, and potential retinal damage and macular degeneration. (6)
Further there is some evidence that blue light exposure at night is linked to diseases (many similar to the lack of sleep related diseases – coincidence?) Study after study has linked working the night shift and exposure to light at night to several types of cancer (breast, prostate), diabetes, heart disease, and obesity. (7)
Even dim light can interfere with a person’s circadian rhythm and melatonin secretion. A mere eight lux—a level of brightness exceeded by most table lamps and about twice that of a night light—has an effect, notes Stephen Lockley, a Harvard sleep researcher. Light at night is part of the reason so many people don’t get enough sleep, says Lockley, and researchers have linked short sleep to increased risk for depression, as well as diabetes and cardiovascular problems. (7)
So what can we do to avoid blue light exposure at night? Specifically at least an hour before bed, but ideally as soon as the sun sets, so yes much longer in the winter when you make more melatonin and you begin to make it earlier.
Remember 98% of light enters the body through the eyes. So you can get nifty blue blocking glasses like these?
Don’t I look nifty. Truth is, there are much more fashionable ones, but these are cheap and do the job. And honestly from the day I started wearing them at night, my body knew what was up. I’ve gotten sleepier and fell asleep much more easily.
Further, you can get apps like f.lux, it’s free, to automatically turn down the blue light on your computer. Though to be completely honest I don’t love flu.x. I think it could do a better job of giving you control over when your light switches, though it’s recent update has improved it greatly. Mac computers have an app called candlelight that I think does a better job at getting all the bluelight out, but flu.x is great for “forget it and set it”, and I generally put on the glasses on top of that.
But remember light also comes through your skin, so if you really want to get hardcore about it, which I suggest you do, change out your light bulbs and/or where full coverage clothing in your house at night. Lowbluelights.com is great for all your orange and amber lighting needs. I’m a big fan of amber night lights. Incandescent, while being phased out (so harder to find), is much better in terms of low blue light than CFLs or LEDs. Halogen lights are also a decent option.
The best sleep hack I know is to block all light in your room at night. Get blackout curtains. Remove your clock. You don’t need it. Turn your phone on airplane mode and use an app like Sleep Cycle as your alarm, which wakes you up when you are at the top of your sleep cycle.
Infrared and UV light
I’ve become a bit of a light nerd. Light is so freaking cool, and as it turns out, it has quite the impact on our health. And if you think about it, it’s not much of a shocker. The sun is what gives us life. The Earth being the perfect distance from the sun allowed life to not only exist, but flourish on this planet, so why wouldn’t it have a big impact on our biology.
Going back to the electromagnetic spectrum, we just talked about how the visible light spectrum plays a big part in our circadian rhythm, in particular blue light, but really the full spectrum, which is why actual sunlight is best for resetting your circadian rhythm (and why those with seasonal affective disorder use full spectrum lighting to help battle it). But now I want to talk about UV light benefits, and how Infrared (IR) and Ultraviolet (UV) light play their part.
Infrared is becoming well known in healing circles as a powerful tool for health. There are handheld tools like Infrared lasers for pinpointing spots, and there are also infrared saunas to soak your whole body in IR light. There is even this really cool company called HigherDOSE that is trying to bring Infrared lighting to all hot yoga studios as there heating source, because IR light emits heat. If you live in a big city you can probably find a yoga studio that has it already, and they are doing it because they know what IR lighting can do for the body. You can even make your own homemade IR saunas and tools, though I don’t have the expertise to share how to do that, it is definitely available on the Internet. Then there is of course the sun as the easiest and most powerful light source that emits plenty of and the complete range of IR light.
Infrared lighting exists in a broad spectrum, ranging from near IR to far IR. Both are beneficial, though far IR is more commonly found in saunas and current healing tools, however, if you can find a full IR spectrum sauna, that is where it is at.
Benefits of IR include: (8)
- lowered blood pressure
- improved circulation
- weight loss
- pain relief
- cell health/immunity
- wound healing
- oxygenation of tissues
Infrared laser therapy helps: (9)
- Reduce pain
- Reduce inflammation
- Enhance tissue healing
- Including muscles, ligaments or even bones
So what about UV light? It’s bad, right? Well too much, yes, it’s probably not great. Burning out in the sun is not a good thing, never will be. However, a little bit goes a long way and that little bit is vital.
We have this cultural fear of UV light. Sunscreen, sunscreen, sunscreen. Well for starters have you ever looked at the ingredients in commercial sunscreen. Gross. Talk about toxic and unhealthy. But more than the fact that commercial sunscreens tend towards unhealthy levels of toxins, how about the fact that getting some sunlight, just a bit, everyday is ideal and healthy. Sunlight, the full spectrum, including UVA and UVB.
Sunlight is the most natural way to get vitamin D. Your body produces vitamin D in response to UVB, and with humans spending 93% of their time indoors (10) coupled with the fact that UVB is varies greatly according to certain times of day, certain times of year and latitude, it is easy to see why deficiency is extremely common. So getting out in the middle of the day without sunscreen for even just 5 minutes (more depending on your skin color and sensitivity) can do you a world of good.
Vitamin D is important, and helps the body function in (11)
- Immune system, which helps you to fight infection
- Muscle function
- Cardiovascular function, for a healthy heart and circulation
- Respiratory system –for healthy lungs and airways
- Brain development
- Anti-cancer effects
There is compelling evidence that low vitamin D levels lead to increased risk of developing rickets, osteoporosis and osteomaloma, 16 cancers (including cancers of breast, ovary, prostate and non-Hodgkin’s lymphoma), and other chronic diseases such as psoriasis, diabetes mellitus, hypertension, heart disease, myopathy, multiple sclerosis, schizophrenia, hyperparathyroidism and susceptibility to tuberculosis. (12)
If you check out the Vitamin D council you can see how vitamin D can play a roll in healing or preventing a huge range of health problems from tooth decay to multiple sclerosis.
UV Light Benefits Beyond Vitamin D
And if you delve into this further, you can see there is some evidence as to why getting some UV light (again not advocating you go out and burn without sunscreen while tanning at the beach) is important beyond the benefits of creating vitamin D (in case you were thinking I’ll just take the vitamin supplement some more):
A study in New York found that summer sun exposure but not vitamin D levels was associated with increased grey matter volume and whole brain volume. (13)
It has long been known that the risk of MS increases at higher latitudes. From the relation with latitude, it appears that low solar UVB doses during winter are an important risk factor. (14)
There was just a study published in 2014, done in Sweden, that tested 30,000 women over 20 years, and it correlated their amount of sun exposure to all caused mortality, which means that anything that they died from. They were twice as likely to die from anything when they got less sun exposure. (15)
Direct immune suppression. Exposure to both UVA and UVB radiation can have direct immunosuppressive effects through upregulation of cytokines (TNF-α and IL-10) and increased activity of T regulatory cells that remove self-reactive T cells. These mechanisms may help prevent autoimmune diseases. (16)
Treating skin diseases, such as psoriasis, vitiligo, atopic dermatitis, and scleroderma. UV radiation also enhances skin barrier functions (17)
Enhancing mood and energy through the release of endorphins (17)
Relieving fibromyalgia pain (17)
Increasing testosterone levels – yes, many people lack this important hormone, including women. A quite old study, 1939 found that getting UV radiation on your chest increases testosterone 120% and it increases 200% when the genitals are exposed. (18)
Humans make several important peptide and hormone “photoproducts” when our skin is exposed to the UVB wavelength of sunlight. (19) These:
- induce relaxation and increases pain tolerance
- protect against hypertension, vascular inflammation, and oxidative stress
- promote blood flow and regulates the immune system in response to acute stressors
- Produce a polypeptide hormone that controls cortisol release by the adrenal glands, thus regulating the immune system and inflammation
- reduce appetite and increases libido
Exposure to the UVA wavelength of sunlight increases the release of nitric oxide from storage. Nitric oxide produces a strong cellular signal that dilates the blood vessels and thus reduces blood pressure. (19)
We’re designed to live in light, in particular, sunlight. Based on heredity and the latitude your ancestors lived at and you live at, we all need different amounts. But, don’t be scared of it, don’t burn, don’t aim to burn, but get your sunlight. Tan’s aren’t bad. Not great for wrinkle developing, but not bad for your health. People who work indoors are much more likely to get melanoma than people who work outdoors. (15)
The vitamin D council explains this well. I encourage you to read the whole article if you are concerned about melanoma. It’s not the sun itself that we need to be scared of, but we do need to be cautious how we go about exposing ourselves to it.
According to many studies, the risk of melanoma increases with recreational UV exposure. But melanoma risk does not increase with chronic UV exposure such as from outdoor occupations. People who participate in recreational UV exposure often go in the sun just a few times a year. Their skin has not been prepared for higher UV doses.
However, when the skin is exposed to UV gradually, such as a few minutes longer each day in the spring, the skin develops a protection factor. This protection doubles or quadruples the time of sun exposure without burning.
Some articles with good sun safety tips.
The Energy Takeaway:
Light from the sun plays a vital role in normalizing our circadian rhythm. A normal circadian rhythm not only helps us sleep which helps us with our daily energy, it also helps support a proper HPA axis which is important for normalized cortisol levels that are so very important to energy production. Further infared and UV light benefits include promoting blood flow and oxygenation, both will help support optimal energy production.
Check out my free webinar: The 5 Keys to Optimal Energy for my biggest and best tips to shortcut getting back and sustaining optimal energy.
The Short of It:
I am not capable of diagnosing or treating diseases. Nor is that my intention. These statements have not been FDA approved. I’m a girl that has been studying holistic wellness for over 10 years, working on my own health, and feel compelled to share the information I have learned, that I believe in, and that has changed my vitality, performance, resilience, and health for the better. I of course can not guarantee its accuracy, though most has supporting scientific studies, it is always important to note that scientific studies are fallible and some are completed much more stringently than others. Again I’m only sharing information that I believe has improved my life. Further this article contains affiliate links (TOS) and I truly appreciate your support.