Red Light Therapy Wavelength Rationale

Authors: Andrew Chow, Michael, Kiamanes, Carla M Parsons

Summary: Redlight Therapy is photobiomodulation, or the ability to alter biology using light. Redlight has many peer-reviewed studies showing it’s ability to increase ATP production or energy in the cell, as well as promoting increased cognitive function, wound healing, collagen growth, skin condition, and muscle recovery, to name a few. Learn about Oval’s rationale behind which wavelengths we choose for the highest efficacy. 

Full Article: 

Red light therapy is photobiomodulation, or the beneficial irradiation and exposure of the body to specific wavelengths of red and near-infrared light and is one of the therapies offered in Oval's life extension pod. Redlight is measured in nanometers, and consists of both visible red light (in the range of 600-800 nm) and invisible near-infrared light (which can go upwards of 1000 nm), rather than being referred to as “red and near-infrared light therapy,” it is colloquially referred to as simply “red light therapy.” Consider all references on this page about “red light therapy” to follow such convention.

Red light is considered the superior color of light to shine on the body because of its ability to increase ATP production via the photoreceptor molecule Cytochrome C. Oxidase and thereby increase Mitochondrial Membrane Potential (MMP) when compared to other colors such as green or blue, which have more muted therapeutic effects. [1][2] In fact, increases in ATP production and MMP from red light therapy have several scientifically demonstrated benefits, including promoting increased cognitive function, wound healing, collagen growth, skin condition, and muscle recovery, among many others.

Our pod offers a unique combination of wavelengths in order to optimize the restorative and regenerative benefits of red light and near-infrared light therapy. These values are based on published scientific research, which indicates that the wavelengths chosen for our pod would yield the maximum therapeutic benefit. These peer-reviewed studies show that wavelengths of 625 - 635 nm, 670 - 680 nm, and 810 - 830 nm yielded the most favorable results in terms of the specific outcome being tested, which ranged from cell adhesion and increased lymphocyte receptor sites, cell attachment, and DNA synthesis. [3][4][5][6] 

These results are important because they demonstrate that cells respond to red light, and they do so in a positive manner. What’s more is that based on these and other studies, it is clear that cells contain photoreceptors that respond more favorably to certain ranges of red and near-infrared wavelengths than others, and the drop-off can be quite dramatic. Figure 1 below, provides a visual representation of a cell’s reaction to a specific wavelength of light in the red and near-infrared ranges. [7] From the graph, it is clear that the highest peaks and lowest valleys are separated by shear cliffs, meaning the most ideal wavelengths are concentrated at the maximas or peaks. 

Below is the original graph based on Tina Karu’s work. 

Note, for the front-facing customer side, such as the header image for this blog, and the second graph in this blog, we converted the graph from a linear one to a non-linear graph for customer readability. 

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The study used to create Figure 1 looked into cell adhesion (as measured in the percent of attached cells), which is an indicator of cell growth and thus a cell’s reaction to red light. Cell adhesion is an important measurement for cells because of its fundamental role in the maintenance and development of tissues, and by extension its effects on body systems as a whole. At the most optimal red light wavelengths, cell adhesion could be nearly 100% (at ~830 nm), whereas at its lowest, it could be in the range of 30 - 40% (~580 nm and ~720 nm), below the levels of the nonirradiated control group. [8] More importantly, just 20 nm away (at ~850 nm) from the high of nearly 100% cell adhesion, the percent of attached cells was only at 60%. What this means in practice is that being just a bit off of the best wavelengths (even by as little as 20 nm) can dramatically affect the quality of red light therapy a user receives. This is precisely why the wavelength chosen in red light therapy is one of the most crucial determinants of success.

While the concept of irradiating different colors on the body has been explored in scientific research extensively when it comes to looking at different red and near-infrared wavelengths as an independent variable, studies are generally few and far between. Instead, most red light therapy studies look into whether or not a single wavelength in the range of 600 - 1000 nm affects a dependant variable of interest, rather than determining the most effective wavelength for the desired dependant variable. 

One of the pioneering researchers in the field of red light wavelength variance is Dr. Tiina Karu, one of the first to explore optimizing wavelengths in the red and near-infrared spectrum. Her studies, along with others, corroborate the importance of wavelength in red light therapy, and the fact that there is a stark difference in the therapeutic value between a change of wavelength as small as even 10 nm in certain ranges.

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Instead of using historical precedent or cost of goods as a determinant of wavelength in red light therapy, we at Oval seek to find the most effective wavelengths in the name of maximizing red light’s therapeutic benefits. The unique combination of wavelengths that we have found to maximize red light’s benefits are 625 nm ± 5 nm, 675 nm ± 5 nm, 810 nm ± 5 nm, and 830 nm ± 5 nm at a ratio of 1:1:1:1. This is in contrast to other red light therapy companies who use wavelengths at approximately 660-670 nm and 850 nm. When we overlay Figure 1 with these wavelengths it is clear that the effectiveness of these wavelengths is subpar. While the difference between the wavelengths 665 nm and 675 nm might not be too stark, the clearer inferior wavelength is 850 nm compared to 830 nm (a cell adhesion of nearly 100% and 70% respectively) (Figure 2).

While wavelength is perhaps the primary driver of the effectiveness of red light therapy, we at Oval believe there are additional ways to ensure maximum therapeutic value is achieved. In addition to varying wavelengths of each color, the amount of each wavelength relative to the others is an important consideration variable. While single wavelengths of red and near-infrared light used individually can have their own benefits, using multiple (effective) wavelengths in tandem can increase the overall effectiveness of red light. [9] This is why our panels utilize a 1:1:1:1 ratio of each wavelength: Each panel has 144 leds with 36 leds of each wavelength, doing so maximizes the relative strength of each wavelength with other wavelengths. In other words, keeping the ratio even ensures that no wavelength is “drowned out” by any other wavelength in order to maximize therapeutic benefit. 

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Sources: 

[1] https://pubmed.ncbi.nlm.nih.gov/28798481/

[2] https://pubmed.ncbi.nlm.nih.gov/8833286/

[3] https://pubmed.ncbi.nlm.nih.gov/15362946/

[4] https://pubmed.ncbi.nlm.nih.gov/14872239/

[5] https://www.jstage.jst.go.jp/article/islsm/10/2/10_2_55/_article/-char/en

[6] https://pubmed.ncbi.nlm.nih.gov/8833286/

[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4581240/

[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291816/