Red Light Therapy: Wound Healing at the Cellular Level
As miraculous as the human body can be at healing itself, sometimes the wound-healing process doesn’t go as planned. When healing is delayed or suppressed, the body becomes vulnerable to infection; the chance of scarring increases; and the individual may experience prolonged pain, loss of mobility, and other complications.
Here, we’ll discuss the benefits of red light therapy as a way to accelerate wound healing. As you’ll see, red light therapy wound healing works from the inside-out by stimulating the healing process of restoring normal tissue.
Before we get into how red light can help, here’s an overview of the healing process.
How Do Wounds Heal?
Whenever the skin breaks, such as with a cut, scratch, scrape, or puncture, it’s known as a wound; specifically, an open wound. There are also internal wounds, which can affect vital organs, arteries, blood vessels, and cartilage. If any of these wounds don’t heal properly, they can have serious consequences.
The skin is the largest organ of the body and the primary barrier between the human body and the outside world. Being the first line of defense, the skin is prone to injury, including wounds like cuts, lacerations, burns, and pressure sores.
Skin-deep wounds usually heal quickly on their own but deeper wounds—those involving nerves, blood vessels, muscles, tendons, ligaments, and bones—take longer.
Stages of Healing
The body has a remarkable ability to heal, given the right conditions. The stages of wound healing and tissue repair are:
Stage 1: Stop the Bleeding and Protect the Wound from Infection
Immediately after the injury, the immune system springs into action to protect the wound (and the rest of the body) from invading pathogens. This is called the inflammatory response.
If a wound is bleeding, the blood will quickly start to clot, and the bleeding will stop. As it dries, the clotted blood forms a scab that protects the underlying tissue. Whether or not a wound bleeds, you can see the immune system in action when you notice redness, tenderness, and swelling around the wound.
Once the bleeding has stopped, blood vessels start to reopen in the area, and new micro-capillaries (tiny blood vessels) form at the wound site to bring oxygen, white blood cells, and nutrients to the site. This stage can take several days, during which the inflammatory response begins to relax.
Stage 2: Tissue Repair and Rebuilding
Tissue growth occurs over the next three weeks or so, depending on the depth and severity of the wound. During this time, the body repairs broken blood vessels and produces collagen, which is a tough, fibrous protein that forms the structure of new tissue.
The wound starts to fill in with granulation tissue (new connective tissue), and new skin forms over that, which is when scars begin to form. Except for minor surface wounds like paper cuts, most wounds result in some degree of scarring.
As healthy tissue grows, it is normally organized into a neat latticework. But when there is a wound, the body attempts to close it as quickly as possible to guard against infection. This causes collagen to align either parallel to the plane of the skin (across the wound, to close it), or in a haphazard jumble, especially if the wound is reopened, such as falling again on a freshly skinned knee.
Because it lacks the normal lattice framework, scar tissue is weaker and less flexible than surrounding healthy tissue. New scars are bright red and will eventually fade, but many scars will not fade entirely. Scars that are large enough can also impede movement.
There is no way to completely prevent the formation of scar tissue, but its appearance can be minimized. Please see our blog post about how red light can minimize the appearance of scarring by stimulating the production of healthy skin tissue.
How Wound Healing Could Be Accelerated and Improved
Now that we’ve covered the stages of wound healing, you may be wondering if there is a way to speed up the process. Our answer to that is yes … and no.
Impediments to Healing
Healing comes from the inside, with activation of the immune system and the growth of new tissue. When a wound is slow to heal, a number of factors could be causing it, such as:
- Infections, which can damage newly formed cells and cause them to malfunction;
- Poor circulation, which can occur for two reasons: not enough oxygen and nutrients are reaching the affected area via blood flow; or there is interference with the flow of lymph, which is produced by the lymphatic system and removes waste and toxins from the affected area;
- Lifestyle choices such as smoking, and heavy alcohol and/or drug use;
- Chronic stress, which interferes with the immune system and impedes the functioning of the parasympathetic nervous system, meaning the part of the nervous system that controls the body’s rest, digest, and repair functions;
- Certain medicines, including corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and chemotherapy drugs; and radiation treatments;
- Chronic inflammation, which causes oxidative stress (an imbalance between free radicals and antioxidants) in cells, thus impeding their ability to perform their functions and causing further damage;
- Mitochondrial dysfunction. Mitochondria are tiny structures inside cells that perform like “energy factories,” within the cells, producing the energy that cells need to replicate, repair themselves, and function normally. Mitochondrial dysfunction means cells aren’t operating at full capacity so they don’t perform like they should, and are more vulnerable to infection and damage. Mitochondrial dysfunction is often caused by chronic inflammation.
The good news? All these impediments to healing can be addressed.
Speeding Up and Improving the Healing Process
Because healing takes place at the cellular level, it cannot be rushed. Some processes, however, can be accelerated and made more efficient.
Take skin cells, for example, which only replicate about once a month. In the case of a wound, new skin cells are being created simultaneously, but they still need time to grow and set into their proper places.
The process of growing new skin can be made more efficient by supporting optimal mitochondrial functioning; even if skin cells won’t grow faster, they will be healthier, and less vulnerable to infection.
Wound healing as a whole can be accelerated, however, by removing obstacles such as oxidative stress, built-up waste, poor circulation, and mitochondrial dysfunction.
Wound healing can be accelerated through:
- Improved mitochondrial functioning, which increases cellular energy;
- Reduced oxidative stress through a modulated inflammatory response. Although acute short-term inflammation is a necessary part of the healing process, if it becomes chronic, it can lead to oxidative stress in cells, preventing cells from functioning properly;
- Increased and normalized collagen production;
- Improved blood and lymph circulation, including the formation of new micro-capillaries at the site of the wound, as well as stimulation of the lymphatic system for improved waste removal;
- Activation of stem cells, which are the body’s “master cells” and a vital part of the immune system; stem cells have the ability to take on the functions of damaged or destroyed cells.
These are the processes of accelerated healing. But what mechanism can stimulate these processes? Red light therapy may hold the answer.
How Red Light Therapy Can Speed Up Wound Healing
Red light therapy, which is also known as low-level light therapy (LLLT) or photobiomodulation (PBM), has been used for over 40 years to promote skin wound healing, among innumerable other health benefits. Red light therapy’s incredible potential was initially discovered by NASA scientists
NASA astronauts have trouble healing injuries while on space flights. While studying the effects of red lights on plants, the scientists tending the plants found that their hand wounds healed faster when exposed to LED lights.
This accidental discovery sparked research into the ways that red light therapies could improve astronaut health and by extension, the health of people not traveling in space.
The science behind red light therapy wound healing is the usage of specific wavelengths of visible light to stimulate beneficial biological processes in the body. The wavelengths are measured in nanometers (nm), and those with the most therapeutic value include red light (630nm to 660nm) and near-infrared light (810nm to 850nm); collectively, these are called “red light therapy.”
Near-Infrared light therapy wound healing works by being absorbed deeper into the body than red light. Red light can be used to stimulate the healing of skin wounds, and NIR can have beneficial effects on deeper wounds that affect the muscles, bone, and connective tissue.
Devices that used low-level laser light therapy for healing were originally the primary method of delivering red light. Today, with technological advances in light-emitting diode (LED) lights, we now have a highly effective, safe, and natural way to promote red led light therapy for wound healing.
When red or NIR wavelengths of light gets absorbed into the skin, cells respond by producing more energy, which in turn helps them function optimally. This is the single most profound effect of red light therapy on wound healing, but it isn’t the only one.
Red light therapy works at the cellular level. From there, a ripple effect takes place, as individual cells improve the functioning of various bodily systems, and together, these supported systems work together to accelerate wound healing.
Here are the mechanisms by which red light therapy supports the healing process, as confirmed by thousands of studies on the efficacy of red light therapy.
Increased Cellular Energy
If you’ve ever gone to work dead tired after a sleepless night, you can see how important it is to pull yourself together and do your job. And yet, all the coffee in the world might not be enough to let you work at your best. You slog along in a fog, but you're not really "there."
It's the same inside your body. Tired cells can’t give their best, but energized cells can.
During a 2005 study, researchers T.I. Karu and SF Kolyakov, of the Institute of Laser and Information Technologies, Russian Academy of Sciences, discovered that when red or NIR light absorbs into the skin, it reaches mitochondrial chromophores, which are photosensitive, meaning the parts of molecules that are responsible for their color. The interaction stimulates increased energy production within the mitochondria; specifically, red light therapy stimulates the production of ATP.
And as previously stated, energized cells can perform their functions, more robustly fight off pathogens, and successfully repair and regenerate themselves.
Reduced Chronic Inflammation: A Modulated Inflammatory Response
Acute inflammation, such as swelling and reddened skin, is quickly followed by the production of new skin structures. If the inflammatory process continues past the initial acute stage, it can lead to oxidative stress in cells which further damages their ability to function normally.
Michael R. Hamblin, who is an associate professor of dermatology at Harvard Medical School and one of the world’s foremost experts in red light therapy, wrote in a 2017 paper about a significant reduction in inflammation in animal studies that focused on brain injury, arthritis, spinal cord injury, and wound healing.
These findings, says Dr. Hamblin, were particularly significant in human studies that focused on chronic non-healing wounds. For studies, research that focused on people with diabetic ulcers found that red light therapy modulated the inflammatory response, which means that the body benefitted from acute inflammation (a necessary part of healing) but that the inflammatory response did not become chronic.
Normalized Collagen Production
Because collagen is found throughout the body, it is an essential component of wound healing. So whether you’re healing diabetic foot wounds, herpes lesions, cuts, or deep abrasions, collagen is necessary for the restoration of normal tissue.
- Type I collagen is found in the skin, tendons, internal organs, and the growing parts of bone;
- Type II collagen is present in the cartilage;
- Type III collagen is present in the bone marrow and lymphoid tissues;
- Type IV collagen surrounds most tissues as a membrane known as the basement membrane;
- Type V collagen is found in the hair and on the surface of cells.
Red light therapy stimulates healthy collagen production as new tissue forms in the deepest layers of a scar. Organizing collagen into a normal latticework can help form healthy tissue, and minimize the formation and appearance of scars.
Dr. Hamblin co-authored a 2014 review of several in vitro and in vivo animal studies dating back to the late 1980s. The review confirmed the effect of low-level light therapy on increased collagen production throughout the body.
Activation of Stem Cells
During the skin-rebuilding phase, stem cells mobilize to the injury site where they have the magical ability to develop into almost any other cells that are needed by the body.
The 2014 research cited in the previous section found that red light activates stem cells within bone marrow, which then mobilize to the site of the injury. This deployment of stem cells is important because neighboring cells communicate with each other. Damaged cells can send the wrong signals to emerging cells. But by sending healthy stem cells to take the place of the damaged cells, the right signals are sent to the new cells. So rather than taking on the characteristics of damaged cells, these new cells take on the desired characteristics.
Improved Blood and Lymph Circulation
Efficient healing relies on good blood and lymph circulation. Red light therapy increases microcirculation, which is the circulation of the blood in the smallest blood vessels. It also increases perfusion, which is the process by which blood or other fluid passes through the blood vessels into an organ or tissue.
In 2017, a team of researchers from Vienna, Austria, conducted an in vitro study to compare the effects of different wavelengths of light on endothelial cells from the human umbilical cord. The study found that red light promotes the proliferation of endothelial cells, which make up the inner layer of capillaries; the ultimate result of red light exposure is the growth of more capillaries in the injured area. This means the delivery of more oxygen, white blood cells, and nutrients to the wound.
Treating Wounds At Home with Red Light
Wounds that require medical attention should always be treated by a doctor. For minor wounds that don’t require professional medical attention, you can use high light-energy output LED panels to administer red and NIR light therapy to accelerate wound healing.
Here are some points you need to know about using low-level light therapy for maximum benefit. You’ll probably want to administer the treatment several times per week for 10 to 20 minutes at a time until the area has healed. Be sure to always keep the wound clean.
- Give your body the support it needs through adequate rest, good nutrition, and stress relief.
- Use a light therapy LED panel that delivers high light energy output. The light needs to be intense enough to “push” into the lower layers of skin and underlying tissue, so don’t bother with portable, battery-operated devices. They simply aren’t powerful enough to do the job.
- Use an LED panel with a combination of red and NIR light. This is because you’ll want to treat wounds at the surface, at their deepest levels, and everywhere in between.
Red light powerfully stimulates the outer layers of the dermis, while NIR light absorbs deeper into the tissue to support deep healing beneath the skin.
The PlatinumLED BIO series lets you choose 660nm (red) and 850nm (NIR) wavelengths, which you can use separately or simultaneously in a 50/50 ratio.
The PlatinumLED BIOMAX series uses five different wavelengths of red and NIR light simultaneously in a ratio that ensures every layer of the scar is impacted by the light.
Get Back to Living with Red Light
Numerous independent clinical studies, animal research, and in vitro lab experiments have confirmed that red light therapy is effective at accelerating wound healing.As a bonus, you’ll discover that while you’re treating a wound, you may also experience some of the more widespread benefits of red light, including better skin health or faster muscle recovery after a tough workout.