How does Red Light Therapy work?
Conclusion at a glance
Red and Infrared LED light therapy works because:
Red light therapy, also called Low Level Laser Therapy (LLLT) or photobiomodulation - is the use of red light (or infrared light) for beneficial properties on the body. These beneficial properties are explained in detail below, but red light (in the correct intensity and dose) has a therapeutic or healing effect on the tissue and body. Practical examples of red light therapy include the use of a laser, or a red light LED, that emits light in a red light spectrum on an injured body part.
You may have heard of red light therapy under a different name, such as:
- low level light therapy
- Soft laser therapy
- Cold laser therapy
- Photonic stimulation
- Low-power laser therapy
If you have already done some research on this site or those of other brands, you will know that light has numerous effects on the body.
- exposure to light affects our mood, our sleep, our hormones and much more.
- Blue light can, for example wake us up or worsen our sleep.
- Red light is the healing and therapeutic help with growth and recovery.
- Infrared light warms us and can help in detoxification.
- UV-B light is used for vitamin D synthesis in our skin.
Light therefore not only functions as a color to illuminate your environment, but actually penetrates the body and then has biological effects in the body. See the following figure. It shows how deeply different types of light waves penetrate the body:
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As you can see, red light has a deep penetration depth compared to other forms of light, such as UV, blue, green or the longer infrared wavelengths, meaning that the red light can reach deeper body tissues. Other non-red wavelengths cannot reach that depth and cannot affect the underlying tissue in the way the red light therapy does. The deep tissue penetration also means that red light can have a systemic effect on the human body, rather than keep its biological effects localized in a specific area. The reason for the systemic effects is the ability of red lights to stimulate ATP production.
This quote from the article entitled Low-Level Laser Therapy for Fat Layer Reduction: A Comprehensive Review states:
The mechanism is based on the absorption of red and shortwave infrared photons by chromophores in the mitochondria (especially cytochrome c oxidase), leading to mitochondrial membrane potential increases, oxygen consumption, adenosine triphosphate (ATP) and a transient increase in reactive oxygen species (ROS ).
A reader of this text simplified this section with the following comment:
It is the energy of the photon used by the body. Just as a plant uses light energy to generate complex molecules through chlorophyll, our own chromophores use the energy of the photons to do the same, just for several reasons: changing membrane potential, increasing oxygen utilization, generating ATP, etc.
Red Light Therapy lamps (and the LEDs often used in them) can be made to give very specific light wavelengths, such as 630nm or 670nm, these LEDs have other advantages. NorahLux light therapy lamps aim to influence the mitochondria throughout the body. Mitochondria are the energy-producing units of our cells. Improving mitochondrial function will improve your body's overall health. Not all wavelengths of red and infrared light are optimally absorbed by the mitochondria. By targeting the LEDs at some highly therapeutic wavelengths, maximum absorption is achieved. Therefore, if you chose wavelengths that are not optimal, most of the energy would be wasted. Traditional incandescent lamps such as incandescent or halogen use many of these intermediate wavelengths that have no proven therapeutic effects, as they do not emit enough light at the very specific wavelength peaks with too much heat.
Only the safest, most proven wavelengths provide optimal health benefits. Natural light is a broad spectrum that includes many wavelengths and colors. Leading photobiomodulation researchers have found in numerous peer-reviewed studies that a narrow band of red and shortwave infrared light is the clinical sweet spot for health. The best light therapy devices use these proven wavelengths: red and infrared light in a range between 600 and 900 nanometers. [3,4]
Cytochrome c oxidase (CCO), is better described in the term electron transport chain complex 4. For every detail that is known about this, it is best to search for it. Youtube offers some graphical representations that make it a bit more tangible. During the fourth phase of cellular respiration (oxidative phosphorylation), specific wavelengths of red and short-wave infrared light break the bond between nitric oxide and CCO. This allows oxygen to bind to NADH, restoring the normal pathway for hydrogen ions to create the electrochemical potential that produces ATP (cellular energy). A simple way to think of this process is that photons are essentially charging your cellular batteries.
Activating cytochrome c oxidase is critical when it comes to photobiomodulation. With this in mind, let's look at the graph below, which shows the activation of CCO at different wavelengths. As you can see, there are specific absorption peaks in the 600nm and 800nm ranges. For example, wavelengths in the 700-730 nm range have very little biological impact due to their inability to activate CCO efficiently.
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Red Light Therapy has been (and still is) used successfully to help heal animals. Red light therapy is also often used to help plants grow. Growers in greenhouses are increasingly using LED lighting with specific colors for specific purposes, so there is a difference between the growth and the flowering period. Red light is one of the options.
Research has shown that light in the red and shortwave infrared spectrum has many benefits for the body. This light usually varies in frequency from 620 nanometers (nm) to about 1000nm. These specific wavelengths penetrate deep into the body tissues and are also very well absorbed by the body. This light range of 600-1000 nm makes up a very small part of the electromagnetic spectrum as shown below:
In fact, it includes only a small amount of the visible light spectrum that we see with our naked eye plus a small portion that is invisible.
Light sources such as the sun and ordinary incandescent lamps emit light in all spectra of visible light - hence the name 'full spectrum light' and this is also why a Red Light Therapy lamp such as a NorahLux will emit a red glow, while the sun will emit a will give a white-yellow glow.
It should be noted that shortwave infrared light around 800-1000nm is actually not visible to the naked eye, but is part of the range of the red therapeutic light due to its health benefits. These questions and the question why a part of the LED does not seem to work are answered.
Traditional incandescent lamps, such as incandescent or halogen lamps, give off red light, but they also produce large amounts of heat with a wide wavelength band and are less effective for very specific therapeutic effects than their LED counterparts.
Do not forget that not only the light color (wavelength) is important, but also the amount of that light (power density).
Scientific sources and medical references: