Therapeutic Light: What Is It and Why Red Works Best

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In recent years, therapeutic light (light therapy) has gained more prominence as a safe, effective, natural and chemical-free treatment modality, becoming more widely adopted by major professional athletes, such as Norwegian footballer Martin Ødegaard and tennis player Casper Ruud. 

What Is Therapeutic Light?

Light therapy (also known as photobiomodulation) is an umbrella term referring to various forms of therapy treatment that use photonic energy of light for purposes of producing therapeutic benefits. 

However, not all forms of light are created equal. Certain wavelengths of light are more beneficial than others, and then there are those that can even be hazardous to our health. So, how do you distinguish between different types of light? 

What Is Red Light Therapy?  

However, there’s still a lot of misunderstandings and misinformation about red light therapy out there, including claims that it’s a bogus new age invention, that it has no scientific basis, and that it’s exactly the same as going to a sauna. Although none of these claims are factual, myths about red light therapy continue to persist. 

Red light therapy, also known as low-level laser therapy or LED therapeutic light, utilizes light-emitting diodes (LEDs) in red and near infrared light wavelengths to stimulate the body’s natural process of healing.

Contrary to popularly perpetuated myths, red light therapy is neither new age nor a hoax. In fact, quite the opposite. Red light as a form of therapy has existed for more than a hundred years, having first been explored by Danish physician Niels Ryberg Finsen. He applied red light in the treatment of smallpox and lupus, and was awarded the Nobel Prize in Medicine in 1903 for his efforts. 

In the mid-1990s, NASA scientists further explored and developed this technology after an accidental discovery during plant growth experiments in space showed that light-emitting diodes helped accelerate the healing of wounds on astronauts’ hands. 

Further experiments demonstrated that red light therapy helped improve musculoskeletal training injuries in Navy SEAL team members by more than 40%, decreased wound healing time in crew members aboard a U.S. Naval submarine, and reduced the pain in children suffering from oral mucositis by 47%.  

Red Light vs Near Infrared Light 

Red light therapy treatments imitate the beneficial effects of natural sunlight at dusk and dawn, but without the harmful UV rays (more on that in the next section). 

Research has shown that this type of low-level laser therapy reaches maximum effectiveness when it combines red and near infrared light wavelengths. 

But what exactly is the difference between the two? Here’s a handy way to compare them: 

Red Light Near Infrared Light 
Belongs to the visible light spectrumBelongs to the invisible light spectrum
Wavelengths of 625-700 nanometersWavelengths of 700-2,500 nanometers
Mostly effective on the surface of the skin Effective both on the surface of the skin and 1 ½ inch underneath it 
Used primarily (though not exclusively) for wound healing, skin rejuvenation, etc. Used to relieve pain, repair muscle, recharge energy, recover faster, etc. 

There are literally thousands of research studies that show the effectiveness of red light therapy, and the list of its benefits is practically endless. Here’s only a few: 

In addition to wound healing, red light has also been proven effective in reducing fine lines, wrinkles, skin roughness, and increasing collagen density, which can improve joint health and skin elasticity. 

Near infrared light can energize your body by increasing the production of adenosine triphosphate, which fuels numerous processes in living cells.

A combination of red and near infrared light can also help relieve pain, repair muscle, and recover faster after an exercise session. 

Red Light vs UV Light 

As mentioned earlier, red light imitates certain healing properties of natural light, except for one crucial difference: it doesn’t include the harmful UV light. But what exactly is UV light? 

UV (aka ultraviolet) light has shorter wavelengths that are invisible to the human eye – typically from 100 to 400 nanometers (compare that to much longer wavelengths of red and near infrared light). 

The Sun contains the full spectrum of UV radiation: UV-A, UV-B and UV-C rays. While UV-A rays are mostly absorbed by our atmosphere, the exposure to UV-B rays can cause not only sunburn, but also increase the risk of DNA and other cellular damage that can lead to cancer

So, although the Sun provides Vitamin D, a necessary nutrient, it also poses risks that can cancel out its benefits. In contrast, red light contains no UV rays whatsoever, and it emits very little heat, so there is no risk of burns, DNA or cellular damage, or cancer. 

Red Light vs Infrared Light

The wavelengths of infrared light are much larger (approximately the size of a pin head) and longer (15 micrometers to 1 millimeter) than those of near infrared light. They’re actually closer to the microwave region of the electromagnetic spectrum. 

Infrared light is typically utilized in saunas through infrared electromagnetic radiation, and it functions through using heat for healing purposes. However, unlike near infrared light that can penetrate around an inch and a half beyond the surface of the skin, infrared light can only reach about 0.04 inches beneath the skin, while the rest of it gets absorbed by the water within our body.

Infrared saunas also emit a high amount of electromagnetic fields that, just like UV radiation, can potentially cause breaks in cellular DNA and even lead to cancer. Because red and near infrared light emit very low levels of electromagnetic fields, this form of therapy is much safer than going to an infrared sauna. 

Red light therapy has been scientifically explored for more than a hundred years, and numerous research can testify to its health benefits. It doesn’t involve heat, UV rays, or electromagnetic fields, which means that not only is it effective, it’s also the safest form of light therapy.