How The Suns Light Works
The sun emits several different wavelengths. To be more precise, the sun emits 1) visible (all the colours of the rainbow); 2) infrared (IR) and; 3) ultraviolet (UV) wavelengths of light.
And you know what’s really interesting?
You absorb those wavelengths through photoreceptors located in the skin. Your body also converts the light into energy (3).
That process works similarly to the well-known metabolic progress “photosynthesis” (4). In photosynthesis, plants use light to convert carbon dioxide into oxygen. Photosynthesis is essential for all plant life on earth.
In your cells, that process is essentially reversed!
Let’s explore that relationship between light and your body a bit further:
Without going into too much detail, the energy-producing processes in your cells are also affected by light in your environment.
That basic process of light absorption by photoreceptors brings many fundamental health benefits.
Clearlight Saunas® offers saunas that use infrared wavelengths to heat you up from the inside. In this article, however, I will not cover that specific topic.
Instead, I’ll break down the latest studies around “red and infrared light therapy” in this blog post in simple understandable terms. I’ll also talk about the benefits of this therapy and I consider some commonly-asked questions.
Contrary to using an infrared sauna, red and infrared light therapy barely heats your body up, but it does provide your body light that penetrates deep into your tissues.
Let’s explore that statement some more:
“Red and infrared light therapy” contains two primary forms of light:
- Red light
- Near infrared light, is a small piece of the infrared (IR) spectrum.
Here is a deeper explanation of the wavelengths used in red and infrared light therapy:
First, red light is made up of wavelengths between ~ 620 and 780 nanometers in length.
Secondly, near infrared light wavelengths are found between 780 and 1,400 nanometers.
Lastly, wavelengths above 1,000 - which heat your body up - are not used in red and infrared light therapy - so we won’t discuss those in this article. In other words, only infrared between 780 and 1,000 nanometers is commonly used!
(If you’re not a physics geek then there’s no need to remember those numbers!)
This red and infrared light therapy I’m talking about is also frequently described with other names, such as “Low-Level Laser Therapy (short: LLLT)”, “LED light therapy”, “photobiomodulation”, and “red light therapy”.
To keep things simple for you, I’ll go with the name “red light therapy” in this article.
So let’s consider why red light therapy is so different from anything else on the market today:
Red Light Therapy History
Red light therapy has been used for decades, although, mostly through lasers. Consumer red light therapy, on the other hand, has only been used extensively for about a decade.
Consumer red light therapy almost exclusively uses LED lights, instead of lasers, which are much safer to apply (5).
When you’re using LEDs, there’s (almost) no risk of damaging any tissues, except under the most extreme circumstances.
The red light therapy sold by Clearlight exclusively uses those side-effect friendly LEDs.
So let’s consider why LEDs are used in the first place:
Contrary to infrared saunas, red light therapy functions almost exclusively based on light and has a very low heat component. In other words, an infrared sauna heats you up from the inside while red light therapy provides you with light that penetrates deep into your body.
In northern Europe, the classic incandescent heat lamps have traditionally been very popular.
These bulbs are mainly used for sinusitis or muscular tension.
Whilst these incandescent heat bulbs also produce small amounts of red and near infrared light, these lamps have nowhere near the same benefits and intensity as their red light therapy counterpart (6).
Fortunately, the red light therapy industry as well as its applications have grown exponentially in the last few years.
New panels that emit new wavelengths and different treatment protocols hit the market every single week.
What’s amazing is that red light therapy has been very extensively researched in thousands of studies. When the correct treatment parameters are used in these studies, about 85% of these thousands of studies show positive results (7).
Due to these promising scientific findings, red light therapy quickly established itself among athletes and Olympic participants last few years.
Natural health clinics and healing centres have also integrated this form of therapy for accelerated recovery to assist their wide range of patients and customers.
Red light therapy has, in fact, taken the health industry by storm. Michael Hamblin, a Harvard University professor, thinks that within a decade, most homes will have a red light therapy device (8)!
How Does Red Light Therapy Work?
Not all light is created equal though. All these wavelengths or rays of light have a different effect or are absorbed differently by the skin.
One classic example is the effect of sunlight on the skin, which, among other things, ensures that the human body can produce vitamin D. Part of the ultraviolet light spectrum initiates the physiological creation process of vitamin D (9).
In red light therapy, two specific ranges of light wavelengths complement each other, which, when used together, cause the effect of “photobiomodulation”.
Let’s break down the term “photobiomodulation”.
In Latin, “photo” stands for “light”, “bio” denotes “biology”, and “modulation” signifies “change”. “Photobiomodulation” thus means “light modulation biology” or, simpler: “light changing life”
Phrased differently, the term “photobiomodulation” describes the metabolism of light energy into electrochemical energy in the human body.
Put in more plain terms, light that enters your body influences the chemical and electrical processes in your body (10). Every single biological process in your body depends on chemistry and electricity (and their interaction).
Or, even simpler: light energizes your body!
As a result, the effects of this supplied energy are versatile. I’ll explain that process in the blog post below.
For the effect of photobiomodulation to occur, you require two specific wavelength ranges which I’ve talked about earlier:
- Red light in the visible range of 600-670 nanometres (nm)
- Near infrared light in the range of 800-860 nanometers (nm)
The merging of these two parts of that light spectrum, at a sufficient intensity, guarantees the process of photobiomodulation is effective. Only using the right parameter will thus result in the desired health benefits.
In other words, if the light output of a panel is very low, you won’t get much if any benefit. Moreover, many wavelengths do not guarantee the desired effect, which is why classic red light lamps do not promote the same health outcomes.
If you were to use the 710 nm wavelength, you won’t get the same benefits as you would by using 630 nm or 810 nm (11).
Well, one mechanism of certain wavelengths of light is that they activate biological processes in your cell’s “mitochondria”. Scientists consider those mitochondria the “power plants of your cells”.
Mitochondria have a variety of functions in the cells, in particular, they are responsible for the production of adenosine triphosphate (ATP). ATP acts as an energy store in the cells and thus, fuels the body. Within a very short time after exposure to the correct wavelengths, the mitochondria upgrade their power station function and produce more fuel as ATP.
The increased ATP production, in turn, leads to more energy in the cells and subsequently the body.
(Alternative theories about the cell’s energy generation exist that I won’t go into here! (12))
The bottom line is this: you need the right red light therapy panel with the correct wavelengths and high light output.
Curious yet? Let’s then take a look at what health benefits you can expect from this therapy:
Red Light Therapy Health Benefits
The list of health benefits is impressively long and will examine them individually below.
In summary, it can be deduced above all that increased cell health or increased cell frequency is an ideal prerequisite for many processes that support a healthy body and mind!
That dynamic is often compromised by stress in everyday life, chronic fatigue, insufficient nutrition and insufficient movement/exercise. All these consequences can also lead to the weakening of the immune system.
At the cellular level, the cell function is reduced and the human body has less energy for vital processes.
For instance, these negative factors lead to an increase in a compound called “nitric oxide” (NO). This increase may be harmful when nitric oxide binds the enzyme cytochrome C-oxidase (CCO).
Without overcomplicating too much, “COO” is part of the energy-creation process in the cell and is needed for cell health. Adding red light therapy will break down the bonds between NO and CCO, therefore increasing overall cell health.
(Phrased differently: COO compromises one necessary step of the energy-creation process in the mitochondria - COO is highly dependent on red and infrared light as an input to function optimally! (13))
Let’s zoom in now and look at concrete benefits which you’ll likely experience from applying red light therapy:
1. Pain Relief
Red light therapy is proven to naturally reduce pain. Studies have shown, in fact, that red light therapy treatments can alleviate things such as chronic back pain, muscle pain, and knee and joint pain (14).
It has also been demonstrated that red light therapy can improve overall healing results after injuries and surgeries, reducing the need for pain medication or other over-the-counter drugs.
That potential pain relief provided by red light therapy results from increased blood circulation within the body, especially to damaged tissue (15).
Furthermore, red light therapy also has the effect of photobiomodulation: an increase in ATP in the mitochondria is achieved, which gives your cells more usable energy and thus enables them to function better.
If a physiological dysfunction is the cause of the (chronic) pain, removing that dysfunction may thus reverse the presence of pain.
And, zooming out again, that optimisation of the functions of the cell is directly linked to faster regeneration of damaged tissue; the body’s own immune system can therefore act stronger and faster to repair internal damages (16).
Hence, several pathways exist through which red light therapy reduces pain. Moving on to the second benefit:
2. Reduce Inflammation (One Of The Main Causes Of Chronic Health Diseases)
Initial research results indicate that red light therapy can help reduce excess inflammation in the body. An excess of inflammation is detrimental to your overall health in many different ways.
Hence, the possibility of lowering inflammation by red light therapy is a very welcome one. Let’s explore the results of current scientific studies:
In a 2010 study, positive developments in inflammation levels within the muscular level were found. That inflammation typically occurs during heavy strain from sports.
When red light therapy was used right before athletic endeavours, moreover, it resulted in pain relief and a shorter regeneration phase (17).
(For you, as an athlete, a shorter regeneration period entails you’re able to train or compete more frequently with a full recovery!)
Additionally, pain relief is observed in various forms of arthritis when red light therapy is regularly applied. A reduction of swelling (associated with arthritis) and stiffening resulted as well. These initial results are fantastic, as people with arthritis often live in pain and also have compromised mobility (18).
The above outcomes can be explained through the aforementioned “photobiomodulation” (i.e. “light shaping life”). Due to the supplied energy by both red and near-infrared light, the production of ATP in the mitochondria is stimulated. Due to the increase in ATP, the body's own processes, such as the supply of blood and oxygen to the muscles, are more efficient and intensive.
Next, here’s another benefit many men and especially women will love:
3. Skin Rejuvenation (Increases In Collagen And Elastin Production)
In the beauty industry, various forms of red light therapy have been known for a long time and are used regularly, especially by stars and celebrities. The main reason for this therapy is the reduction of inflammatory symptoms in the skin. Due to increased blood and oxygen circulation, the damaged skin tissue can be repaired more quickly, resulting in increased regeneration and better overall looks (19).
In fact, many people already report younger-looking skin after their first red light therapy sessions (Yes, even 20 and 30-year-olds frequently notice a difference).
Red light therapy, for instance, results in an increase in the body's own collagen (20). Collagen is a protein produced naturally in the body, which among other things provides structure and stability, e.g. in bones or in the skin.
Increased production of collagen through an application of red light therapy can therefore also lead to an improvement in the skin's appearance, which is why it has long been used in the beauty industry.
Fortunately, red light therapy now allows consumers all over the world to access these skin rejuvenation benefits. In the past, you needed to visit an expensive clinic to get these results.
Today you’ve got access to red light therapy at your fingertips!
And there’s more:
4. Muscle Recovery And Conditioning
Exciting results have also been achieved in terms of muscle recovery and conditioning. Improvements in muscle activity have been recorded in terms of strength, endurance and general performance improvement.
For instance, applying red light therapy results in an increase in maximal muscular upper-body strength and an increase in grip strength (21; 22). Similar results are obtained with regard to leg strength.
These health benefits are recorded in both women and men - both sexes attain an increase in overall strength after several sessions!
Here’s why that outcome is remarkable:
As a result of quicker recovery, you’ll experience an increase in general performance and a shortening of the regeneration phase. That combination is very exciting for both amateur and professional athletes because you’ll have an edge over the competition!
As the CEO of Clearlight Infrared Cabins, I expect the use of red light therapy on the performance level to be increasingly accepted in society in the coming years.
5. Improved Thyroid Health
The human hormone balance is a complex scientific topic. The interrelationships of hormones, basic physiology, and overall human health are currently heavily scientifically researched all around the world.
Right now, research is looking at how red light therapy affects the thyroid, one of the most important hormone glands in the human body. When fully functional, it regulates the balance of many downstream hormones.
Without a properly functioning thyroid, for instance, your body cannot optimally create:
- stress hormones that make you feel awake, such as adrenaline
- hormones involved with feeling well, sexuality, and fertility, such as testosterone. Testosterone also helps both men and women feel strong.
- hormones involved with kidney function.
- thyroid hormones are even involved in growth in puberty, such as the growth of your bones, for instance!
And much more...
Initial research has shown that red light therapy improves your overall health if you’ve got a common thyroid disease such as hypothyroidism and thyroiditis. In some cases, red light therapy can even help patients reduce or eliminate their need for levothyroxine - a commonplace thyroid medication (23; 24; 25).
Of course, the precise effects and outcomes in terms of hormonal balance and health affected by red light therapy are still being studied. What is exciting, however, is that there seems to be a strong connection between light exposure (in this case, through photobiomodulation) and overall hormonal health.
For that reason, I and others at Clearlight Infrared Cabins® keep a close eye on further research studies in this area. When new studies emerge, I’ll report on them to you!
Many people experience insufficient light exposure in their lives nowadays, which can contribute to thyroid problems in many cases. Hence, red light therapy is a perfect tool if you’re sitting indoors very frequently.
And, that’s not all yet.
6. Testosterone Increases - Especially In Men
Promising initial research has emerged on testosterone and red light therapy: initial research shows that testosterone therapy is an effective, natural tool for hormone health in men, including improving testosterone levels (26).
A randomized, placebo-controlled pilot study was conducted in 2016 by the University of Siena in Italy, in which 38 men with diagnosed low sexual desire were analyzed.
Here’s the study setup:
One group of men received red light therapy treatments in the morning, while the other group did not receive light therapy. The group of men treated with light therapy increased T levels significantly and attained higher sexual satisfaction in addition.
There was no increase in testosterone in the control group. The group with active light therapy experienced a huge increase from about 2.1 ng/ml to 3.6 ng/ml in only 2 weeks. To put that number in perspective, that’s a whopping 70% increase in testosterone!
Even though I’ve already alluded to this fact, let’s consider what makes testosterone so important:
Testosterone is a sex hormone that plays an important role in the body. In men, it is said to regulate the sex drive (libido), bone mass, fat distribution, the size of muscle cells, overall strength, and the production of red blood cells and sperm.
You might not know, however, that women also produce small amounts of testosterone in their ovaries and adrenal glands. Even for women, that testosterone is important.
Testosterone is also a building block for other hormones. In both sexes, for instance, a small amount of the circulating testosterone is converted into estradiol, a form of estrogen (27).
For female reproductive tissue and bone mass growth and maintenance , that “female” sex hormone estrogen and testosterone closely work together. Both hormones also influence behaviour.
Red light therapy is becoming increasingly interesting for women for that testosterone-optimizing effect. With regards to optimizing testosterone levels, the mode of action is somewhat different for women than men though:
One study shows that red light therapy elevated levels of “dehydroepiandrosterone” (DHEA). DHEA is essential for the synthesis of sex hormones and the production of progesterone, estrogen and testosterone. When women aren’t near their ovulation, they rely on the adrenal production of DHEA to maintain progesterone levels and prevent estrogen dominance (28).
In essence, higher DHEA helps you feel and perform better as a woman, even though you might not be in your “cycle high”!
Conclusion? Red light therapy can have an important positive influence on hormonal health in both men and women!
And there’s more:
7. Sleep, Melatonin Hormone And Circadian Rhythm Optimisation
Initial clinical research also shows that red light therapy can improve sleep quality and duration and help you produce more of your own melatonin (29).
Well, light plays an essential role in the sleep cycle. The body's internal clock (also called circadian rhythm) interprets light as a benchmark of waking and sleeping times.
Traditionally, sunlight, especially in the morning and evening, helps to tell your body what time it is. When the sun sets in the evening, for instance, we are already moving very much in the red colour of the light spectrum and your body gets a signal it’s time to wind down.
Remember that red light therapy contains ~50% red light. This reddish part of the spectrum is ideal for the evening because it has a low colour temperature - much lower than blue light and therefore very close to the natural sunset (30).
Research has shown that red light supports the sleep cycle and does not disturb it like bright blue light (31). It’s mainly the blue light, emitted from screens and regular light bulbs that wakes you up.
During the morning, moreover, red light therapy helps communicate to your brain that it’s daytime, which results in more melatonin secretion at night.
Sounds great right?
Let’s consider one last benefit:
8. Mental Health - Countering Seasonal Affective Disorder (SAD) And Depression
Light therapy also shows potential for improving the treatment of depression, SAD and mental health.
Seasonal depression affects millions of people worldwide. The lack of natural light every day is a factor that plays an important role here. Unfortunately, more and more people no longer spend large parts of their day in natural light, but mainly in front of computer monitors or other electronic devices.
Americans, for example, spend over 90% of their time indoors on average (32).
Natural light is of elementary importance, not only for vitamin D production but also for your internal clock, as described above (33).
To me, it’s a matter very close to my heart to motivate you to spend more time in nature and natural light. Sadly, for many working people it is not possible to spend much time in natural light during the week because of eight to ten-hour working days.
Fortunately, there’s a solution: red light therapy can provide an alternative source of light exposure. The health benefits of this therapy on a physical level have been described above.
And with regard to your mental condition promising scientific outcomes to exist as well:
For instance, red light therapy can directly contribute to mental health:
In 2018, leading researchers in the field of mental health conducted the pilot study "Elated-2" (34). During this study, transcranial near-infrared light therapy for people with severe depression symptoms was tested.
(“Trans-cranial” means the light diodes are placed on the skull and the light penetrates into your brain!)
After only 8 weeks of treatment, there was a medium to large-size positive effect size - which is similar to antidepressant medication without side effects! This groundbreaking study has fueled optimism for broader use of natural light treatments for people with depression.
And there’s more evidence for the thesis that red light therapy affects mental health:
Let’s consider a 2017 study involving 39 people with both traumatic brain injuries and mild to severe depression symptoms. The outcome? Once again, the light has a strong antidepressant effect (35)!
In fact, 36 of 39 study participants showed a clear positive reaction. In 32 of these people, the improvements were statistically significant and resulted in complete remission of clinical depression!
The same study also showed that participants who received more frequent and overall more daylight treatments achieved better results than participants who received fewer treatments with light!
The story gets even better though:
Suicidal thoughts were also resolved in most patients: The researchers found that suicidal thoughts stopped in almost all patients except for two participants.
In follow-up studies, the researchers also concluded that patients remained in a reduced state of depression for up to 55 months after one single treatment.
Even the currently published data is extremely positive. These results also provide a good basis for further studies.
Summarising the above health issues, it is obvious that red light therapy has a wide range of health effects.