Red light therapy - Ask Dr. P

How I Used Red Light to Speed Healing of a Bad Knife Cut

by Pain Doc | Mar 29, 2022 | Red light therapy

Recently I had been careless in the kitchen while cutting food and sustained two, pretty severe cuts on my left hand in separate incidents.

The first one occurred shortly after last Thanksgiving when I was using a very sharp carving knife to shave off the last bits of spiral cut ham off the bone. I held the knife with my right hand and gripped the ham bone with my left hand. The knife slipped and cut deep into the side of the base of my left index finger. The knife was so sharp that it left a surgical-quality incision; deep but very clean edges (not jagged). I could see the layers of epidermis and dermis with the distinctive, yellowish subcutaneous fat as the flesh separated, and seconds before the blood started to flow. The wound went down to the muscle and probably cut a few muscle fibers as well.

The image below shows the layers of skin, and the black arrow represents how deep the cut went. Below the muscle layer is bone (not illustrated):

Layers of the skin

The second, more recent one occurred while I was cutting an onion (NOTE: never cut an onion on the convex side, because not only is it uneven it is slippery and presents a high risk of knife slippage, especially if your knife is not very sharp). This time, the knife slipped and I again suffered a deep cut this time to the lateral, distal middle finger at the level of the base of the nail. This also cut past the dermis and was stopped by the hardness of the nail.

In both of these laceration wounds, there was profuse bleeding. I went through many Kleenex tissues and kitchen paper towels to stop the bleeding. Facial tissues and kitchen paper towels are good for such cuts because not only are they highly absorbent, they shed tiny fibers into the cut, which are used by the fibroblast reparative cells for scaffolding as they lay down collagen fibers to fill in and close the wound, as well as scaffolding for clotted blood that stops the bleeding. These fibers become part of the scab that eventually disappears, so no need to worry.

The main stages of wound healing. Credit to © Guniita | Dreamstime.com

When the bleeding stopped, I gently cleaned around it and put a bandage on, with firm but not too tight pressure. Then I used my red light therapy torch device to accelerate the wound healing. I took off the bandage and applied the light to the cut 2-3 times a day, for about 6-8 minutes each time. I placed the torch directly over the cut, so there was light contact. Long story short, the wounds healed completely in little over two weeks!

Mind you, these were NOT scrapes, abrasions, or superficial paper cuts. These were deep lacerations. The first one on the base of the index finger, which I should have gotten stitches or surgical glue in retrospect due to its severity, I estimated to be 1.8 cm long and 4-5 mm deep. Here’s what it looks like today:

Cut index finger healed scar

The second one was about 6 mm long and 3 mm deep, which would have been deeper if the hard nail bed wasn’t there to stop the knife, as I was putting a lot of force into cutting the onion.

For the second cut, I decided to take pictures to document the healing,

Images of my deep finger cut, treated with Red Light Therapy over 14 days

Picture taken 30 minutes after sustaining cut

1st red light treatment

Day 2 of cut finger

Day 3

Day 6

Day 6 rlt treatment

Note, I actually applied red light to the wound almost daily and include only pictures of two treatments here.

Day 8

Day 10

Day 15

You can see the dramatic changes in the way the cut healed in such a shorter period of time. The inflammation and swelling lessened; the space between the skin closed just after a few days, and the redness decreased until just the dead cut skin remained as a remnant of the cut. I’ve had these kinds of cuts before where I did not have red light therapy available, and they took about 50% more time to completely heal. So, that’s my best estimate of the benefits of using red light therapy to heal injuries—for small wounds such as these, it can shorten the healing rate by about 50%; meaning, red light therapy can accelerate healing a flesh wound to completion in 2 weeks, that would normally take 3 weeks to fully heal.

How Does Red Light Therapy Work?

I’ve written about how red light therapy works several times on this blog, and made some videos on YouTube explaining red light therapy. Basically, red light uses photonic (light) energy to modulate (control; affect) certain biological activities that occur following injury.

Photons, the smallest units of light, are packets of energy and are received by parts of cells called chromophores. Chromophores are found in DNA, hemoglobin, proteins and most importantly, the mitochondria—the components in all cells whose function is to generate energy for the cell in the form of molecules called adenosine triphosphate, better known as ATP.

Photons from red light (wavelength of 620-750 nm, or billionths of a meter) tend to upregulate (enhance; trigger) some of the metabolic pathways involved in wound healing; notably collagen synthesis, reparative cell migration to the wound area, ATP production in the mitochondria; and downregulate the inflammatory and pain-producing pathways (it helps reduce swelling and redness).

What the Resarch Says About Red Light Therapy

If you wish to read less biased, more scientifically-based information on health and therapy-related topics, which you should as the internet is full of unreliable and often downright false information, go to Pub Med. This site is basically an index of medical research produced by those directly involved in treating medical conditions (medical researchers, doctors) and evaluating certain therapeutic interventions for those conditions. Pub Med is free to the public (other medical databases require a subscription).

A quick search on Pub Med on the efficacy of red light therapy (also referred to as phototherapy and LED-Low Level Light therapy) produced a study, among many others, in the medical journal Laser Therapy

Here’s a snippet from the abstract:

“…Among the clinical applications, non-healing wounds can be healed through restoring the collagenesis/ collagenase imbalance in such examples, and ‘normal’ wounds heal faster and better. Pain, including postoperative pain, postoperative edema and many types of inflammation can be significantly reduced.”

Kim, W. Is light-emitting diode phototherapy (LED-LLLT) really effective?2011;20(3):205-15.

And as I like to mention whenever explaining the therapeutic effects of red light, it is actually common knowledge that light has beneficial effects on living tissue. Three, well-known examples are: how light catalyzes photosynthesis in plants, enabling them to synthesize sugars for their energy needs; how UVB light starts Vitamin D production in the skin; and how animals rely on the diurnal cycle of sunrise and sunset to regulate their biorhythms, the patterns of physiological activity involved in the functioning of all living organisms.

A fourth example that suggests the connection between light and health that isn’t quite fully understood by science is Seasonal Affective Disorder (SAD), a mood disorder characterized by depression that occurs at the same time every year in regions where there is less sunlight at certain times of the year.

In summary, therapeutic red light can speed up wound healing by accelerating the metabolic pathways involved in tissue repair. It is therefore logical to conclude that red light can also help with other types of tissue healing such as bone fractures, tendinitis, muscle bruises, gum and tooth pain, vascular pain, and nerve pain. There are even red light devices to help relieve sinus pressure and improve certain gynecological conditions.

As far as red light therapy devices go, the most common types are the handheld red light torch as I mentioned in this article, which resembles a small flashlight and are ideal for focused treatment on small wounds/injuries; and the multi-LED wraps, which can be used for larger areas such as for low back (lumbar) pain and which can be wrapped around an extremity such as the knee, elbow, or shoulder. Some people even use red light LED wraps to reduce fine facial wrinkles. You can also place your feet on an LED wrap placed flat on the floor to treat plantar fasciitis or general foot aches and pain.

Finally, there are the more expensive, “industrial strength” red light panels which are popular in medi-spas for whole body red light therapy skin treatment.

Bottom Line: Red light therapy devices make a great addition to your home therapy kit and are a great investment in your health because they are relatively affordable; are safe to use; are easy to operate and portable (take to office or travel); and most importantly, are known to provide good results for tissue repair and pain reduction, and have published medical research to back their efficacy in this regard.

What is Red Light Therapy, and Can it Help Arthritis?

by Pain Doc | Feb 13, 2022 | Arthritis, Red light therapy

Red light therapy (RLT) is a type of treatment provided in clinical and cosmetic settings that incorporates red light to improve the skin’s appearance, such as reducing fine wrinkles, scars, redness and acne. It is also used in the medical setting to help reduce pain and increase healing in the joints, such as tendinitis, sprains/strains, and arthritis.

Red Light Therapy is also known as:

Phototherapy
Photodynamic therapy
Photobiomodulation
Low-level laser light therapy*
Low-power laser therapy*
Cold laser therapy*
Biostimulation
Photonic stimulation

*this is a misnomer, because red light therapy does not use laser energy.

Interest in red light therapy emerged decades ago when NASA conducted experiments on growing plants in space and healing injuries to astronauts. Results of this research pointed to a connection between red light and positive, biological effects on human tissues. This ability of light (photons) to alter biological activity in living cells is called photobiomodulation and is the means by which RLT achieves therapeutic benefit.

What is Light?

Understanding this requires some basic knowledge of how the eye works, and physics.

First of all, vision is possible only in the presence of light. This means light must bounce off objects in your visual field and enter your eye, which then “translates” the bounced light into an image that is perceived by your brain.

But how do we perceive color? White light is actually made up of wave energy that propagates in multiple wavelengths. It is this difference in wavelengths, the molecular properties of all objects, and the design of the human eye’s retina that creates the perception of color. Objects that appear a certain color reflect the wavelength of just that color into your eye and absorb all other wavelengths. For example, a red shirt reflects the red wavelengths and absorbs the blue, orange and yellow wavelengths. Altogether, these component wavelengths of white light is called the visible spectrum of the electromagnetic spectrum, which is shown here:

Electromagnetic energy exists as an electrical field with a magnetic field 90 degrees to its axis and propagates at the speed of light. The electromagnetic spectrum is the range, in wavelengths, of electromagnetic energy existing in nature, from the very tiny wavelength gamma ray (.0001 billionth of a meter) to the very long wavelength of AM radio (100 meters). Light is in between these extremes and is the only EM waves humans can see, between the wavelengths of about 380 to 700 nanometers (nm, billionths of a meter).

When light passes through a crystal prism, it bends. Since light is made up of different wavelengths, the component EM waves of white light behave differently (bend at different angles and speeds) as they enter the prism and can now be visually distinguished from one another as separate colors in a band: red, orange, yellow, green, blue, indigo, violet. Similarly, rainbows form when suspended rain droplets bend the sun’s light and separate it into its component colors.

RED light is the longest wavelength of visible light, while VIOLET is the shortest. As the electromagnetic wavelength increases, the frequency (the number of times the wavelength passes a fixed point, measured in hertz – Hz) decreases, and so does the amount of energy it carries. So, the very small wavelength/high frequency gamma and x-rays carry a lot of energy and are dangerous to tissues. You may have heard that ultraviolet (UV) light can cause skin cancer. This is because much of its energy is absorbed by the skin, where it does damage to cells. Red light, being the longest wavelength of light, doesn’t have the energy level of UV and therefore does not pose danger to tissue; in fact, as we will discuss later, it has beneficial effects to tissues.

How Does Red Light Therapy Work?

Red light therapy is used to:

Improve wound healing
Reduce pain in joints
Treat tendonitis
Reduce headaches
Reduce stretch marks
Reduce wrinkles, fine lines and age spots
Improve psoriasis, rosacea and eczema.
Improve appearance of recent scars
Improve hair growth in people
Improve acne

It’s well established that light can initiate biological change in living organisms. Perhaps the most well-known is photosynthesis, the series of biochemical reactions where sunlight energy catalyzes the formation of sugar (glucose molecules) in plants. Photons from light get absorbed by tiny structures in a plant called chloroplasts, which provide the biological machinery to synthesize glucose (basically, stored energy) from inorganic carbon dioxide and water.

Another example of light effecting change in living tissue is vitamin D formation, where the pre-cursor of vitamin D is created when UVB light strikes 7-dehydrocholesterol molecules in the skin

Sunlight catalyzes Vitamin D synthesis in skin

With red light, the pathway is likely similar. Many research studies have been conducted over the years to uncover the mechanism behind red light photobiomodulation; i.e. the nature of its therapeutic effects. What is definitely known is that the red light wavelength (in the 660-700 nm wavelength range) tends to get absorbed in the nucleus and mitochondria of cells, in locations called chromophores. Mitochondria (image below) are the structures where energy is generated for the cell, much like the previously mentioned chloroplasts in plant cells. The nucleus contains the DNA, which is the template for protein synthesis.

We also know that photons can “excite” electrons – the tiny charges that orbit atomic nuclei. Cells and all their parts including the mitochondria are of course made up atoms. An “excited” electron means a movement of an electron to a higher energy orbit (further from/ less attracted to the nucleus).

In short, red light stimulation increases the energy state of electrons in sick tissues, enabling faster/enhanced reaction between adjacent molecules, as electron interactions between atoms are the basis of all biochemical reactions. This may translate into the cell “speeding up” its activities, particularly respiration (ATP formation from glucose via the Krebs cycle, i.e. energy production) as well as waste elimination and gas exchange. Redox signaling is the term used to describe this activity, and is the leading hypothesis for the mechanism of red light photobiomodulation.

With enhanced cellular signaling:

If the cell is a fibroblast, it could lead to faster wound healing, as fibroblasts migrate to the injury/damaged site to synthesize and lay down collagen fibers.
If the cell is a stem cell (undifferentiated cell), it could enhance the transformation of stem cells to fibroblasts or chondrocytes, which make collagen and cartilage, respectively.
If the cell is an epidermal cell, it could mean faster cell turnover to clear out abnormal cells in skin conditions such as eczema and psoriasis.

Cells are programmed to respond to specific extracellular signal molecules for development, tissue repair, immunity, and homeostasis. Errors in signaling interactions may lead to diseases such as cancer, autoimmunity (such as rheumatoid arthritis), and diabetes. Given this, it is feasible to assume that if red light therapy can enhance cell signaling, it can benefit these cellular functions and support tissue healing and pain reduction.

Red Light Therapy is Shown to Reduce Inflammation

Many studies found that red light reduced inflammation in tissues. Inflammation is the body’s response to injury or some kind of irritant and is characterized by redness, swelling, and pain. It involves a complex series of steps involving multiple protein clotting factors in the blood and tissues.

Inflammation also involves several types of cells involved in the reparative process, including macrophages (“cleaner” cells that remove debris), basophils (a type of white blood cell that secretes histamine and heparin to make blood vessels more leaky and manage clotting), and fibroblasts. It also involves cytokines—chemical signaling molecules that cells use to communicate and coordinate activities within themselves and with each other.

Inflammation often gets out of hand at the injury/ damaged tissue site and contributes to the problem by increasing pain and delaying healing. In fact, diseases like arthritis, irritable bowel syndrome, vascular disease, diabetes, and even Alzheimer’s disease involve chronic (ongoing) inflammation. This is the basis for the utilization of anti-inflammatory medications such as steroids and non-steroidal medications (NSAIDs) like Tylenol and Ibuprofen for inflammation.

The inflammation-reducing ability of red light therapy is likely due to its ability to enhance cell signaling and molecular flow in the cell. One study notes that overall reduction in inflammation is one of the most reproducible effects of photobiomodulation [from red light]. This is particularly important for inflammatory diseases affecting joints; acute trauma, lung disorders, and brain injuries resulting in inflammation.

Another proposed model to explain how light therapy works is photon-mediated ion channels in cell membranes (image below). Basically, ion channels are the passageways in membranes (think tiny gated doors) where ions flow through, which require energy to open. An electrical gradient is formed as the ion concentration differs on either side of the membrane, and this gradient can be used to drive movement of molecules into and out of the cell, very much like voltage. In fact, this is how neurons produce nerve impulses. Red light photons may be able to activate these ion channels, thereby boosting efficiency of ion flow and helping the cell maintain equilibrium.

Ion channels create energy potential in cell membranes

Should You Try Red Light Therapy for Arthritis?

Given its photobiomodulation ability, red light can be a useful, self-administered treatment for skin conditions and tissue injury/pain. It has powerful effects of improving cellular function to diseased/ injured tissues, which can improve recovery and healing. Being lower frequency, it is not harmful to the body, unlike UV light.

However, red light therapy should not be considered a “magic bullet” for “curing” things. Every person is different, and if you have complicating factors in your health and/or your condition is advanced, it may not work as well. While the human body has remarkable regenerative and healing abilities, there are limitations.

For example, in the case of advanced degenerative osteoarthritis of the knee or hip, much of the cartilage has worn away, and there are multiple areas of exposed bone. Normal, healthy cartilage that lines joint surfaces is smooth and resilient to pressure. Unlike the epidermis (skin), it does not regenerate very well, so if you lose quite a bit of it or tear it, it cannot regrow back to normal.

Osteoarthritis of the knee

But, if you are at the very early stages of osteoarthritis, red light therapy can be very helpful in arresting its progression. Arthritis usually appears mid-age, but if you engaged in heavy contact or heavy impact sports such as football and gymnastics, it may start earlier. What happens is tiny disruptions in the cartilage start to gradually separate, much like how a tiny crack in your windshield “grows” in length as your car absorbs shock from the road each time you drive. These tiny separations then form pits in the cartilage, which widen. Bone is exposed, inflammation sets in, and you’re on your way to an eventual knee or hip replacement some years later. But if you apply red light therapy to the tiny disruptions as they form, there is a much better chance of arresting their progression by stimulating cartilage growth. The red light will energize chondrocytes, the dormant cells embedded in the cartilage matrix tasked with maintaining it, and can stimulate the proliferation of chondroblasts, the cells that secrete collagen matrix.

You can still apply red light to an advanced osteoarthritic knee for palliative purposes, since red light can suppress inflammation and therefore provide some degree of pain relief. If doing so allows you to stay on your feet a couple more hours in a day, then that is definitely a positive benefit to your quality of life.

A good solution for applying red light therapy to the knee is the 120 LED wrap. It is a flexible pad containing 120 light emitting diodes (LEDs) with each diode containing one (1) 660 nm red light emitter and two (2) 850 nm infrared emitters. You wrap it around your knee and hold it in place with an elastic band that comes with it, and press a button.

Alternatively, if you are patient, you can use a red light torch device. This requires you to hold it in place for a couple of minutes. The good thing about the torch is that you can target small areas. For example, if you know you have a cartilage tear on the inside of your knee joint, you can press the torch over it and concentrate the light on that one spot. The torch is also good for small joints; i.e. knuckles.

As always, when you self-treat conditions use a multi-pronged approach: improve your diet, get enough rest, drink enough water every day (sometimes not easy to remember!), avoid ingesting toxins as best you can (nix smoking, alcohol, processed food, excessive pollution); get fresh, clean air by walking where there are lots of trees; exercise/ move often to strengthen your muscles and heart, and avoid negative thinking, which elevates stress hormones. Do all these things consistently and you can rest assured that you are giving your body its best chances for recovering from disease and pain.

Two Modalities to Heal Low Back Pain in Half the Time

by Pain Doc | Oct 20, 2021 | Low Back Pain, Pulsed EMF, Red light therapy, Self Treatment

Hey, I know there are millions of pages on the internet on how to fix low back pain. It can be a dizzying experience searching through them. It’s information overload.

I began blogging on this site around 2010, but actually have been writing articles on things like exercises for low back pain, neck pain, sprains and strains and so forth, since about 1994 when the internet was in its infancy. Fast forward 28 years, and now there are tons of articles and videos online, including mine. Much of the online content for treating low back pain is good: well-written, easy to understand and follow, and backed by evidence. Others are mediocre; just a re-hash of old-school approaches to treating back pain (rest, ice, no heavy lifting, etc.).

If you know me, when it comes to teaching others how to self-treat pain, I like to write fresh, interesting and innovative content. I figure that there are more than enough good videos on stretching and exercising for low back pain. What I like to do is explain the etiology of pain and propose interventions to prevent that pain from developing or getting worse.

If you have acute (recent onset) low back pain, research shows that in most cases, it will go away on its own if you just take it easy for a couple of days. Sure, icing, applying hot packs and no heavy lifting are obviously recommended to prevent re-aggravating the condition. The problem is that most people can’t afford to wait that long, and don’t like being in pain. They have a job, they have responsibilities to other people, and, they want to have fun and do the things they want to do.

For these individuals, there are a couple of home therapies I recommend, to shorten the healing time.

When you have low back pain, muscles and ligaments in and around your spine are generating pain. Something was disrupted mechanically, and inflammation is going on – blood vessels are releasing histamine and heparin and the inflammatory cascade is active—heat, redness, swelling, pain. The inflammatory chemicals irritate sensory nerves, causing some of the pain; as well as the pressure from the swelling. The nerves themselves may be over-firing; generating a level of pain that is not really proportional to the amount of tissue injury.

So with that, my go-to home therapy is a combination of Pulsed EMF and Red Light. Pulsed EMF is an externally-applied, pulsed electromagnetic field. The field, which is similar in frequency to the body’s own natural EM fields, passes through your body and essentially energizes the membranes of cells.

Cell membranes let things in and out of the cell, especially synthesized proteins, nutrients, oxygen, and waste products. They do this via active and passive transport, which both rely on membrane potential—a weak voltage created by negatively charged ions on the outside of the cell, and positive ions on the inside. Like how a battery’s voltage can power a light bulb, a cell’s weak voltage along its membrane powers the exchange of molecules in and out of the cell.

When cells (in this case muscle, bone, nerve, blood vessel cells) are physically damaged or weakened, this exchange is hampered and the tissues are slow to recover and return to a normal, non-pain state. Pulsed EMF lends a boost to this energy, helping cells become more robust in their healing and recovery activities.

Red Light therapy also can energize weak cells, but via photobiomodulation. Cells absorb red light in the 660-720 nanometer wavelength (electromagnetic energy), due to their molecular composition. Photons strike the nucleus, mitochondria and membrane, which changes the oxidative state of the cell. When this happens, it triggers cell signaling pathways related to metabolism and energy production. The cells increase their ATP output, which gives them more energy to repair damaged sites and synthesize needed repair proteins.

Pulsed EMF devices for home use are very easy to operate. Usually, it’s a matter of just pressing the power button, and sometimes a Mode button and Timer button. One of the better models is the BioBalance. You can order it with a full body mat, or a pad. Simply find a comfortable place in your home such as your sofa; place the mat on it, and lie down so that your low back is directly over the mat. No need to remove clothing; the pulsed EMF field passes right through. Do it 3x day for 20-30 minutes/ day to help your body heal and recover.

Another option is the OMI full body PEMF mat. It is lower power than the BioWave, but sometimes that works just as well, as the EM fields are very subtle. You don’t want fields that are too strong. Remember, your body already produces weak magnetic fields; you just want to complement them with a boost of comparable energy.

Red Light therapy is also a great investment in your health. I recommend getting a red light LED wrap, or LED panel. The wrap is a flexible pad embedded with red light LEDs emitting red light and infrared light (660, 820 nm). The red light diodes create photobiomodulation while the infrared diodes provide deep penetrating heat to dilate blood vessels and increase oxygen delivery to cells.

Red Light panels come in different sizes. The small ones are popular for treating facial skin conditions and beautification. The larger panels are better for treating pain. You can mount or hang the panel on the wall, and position yourself so that you are exposed to the red light (usually requires standing up).

In summary, if you are prone to getting lower back pain or have chronic pain issues, Pulsed EMF and Red Light Therapy are two, powerful and safe modalities that can be used at home for self-treatment and are easy to operate. Best of all, they have a long history of medical research to support their use in treating pain and healing injury. It does require a modest investment, but what is more important to your health and well-being? Without this, nothing else matters.

Can Red Light Heal Injuries and Lessen Pain?

by Pain Doc | Jul 21, 2015 | Red light therapy

The color of red has a psychological connection to stopping– stop signs, stop lights, red warning signs and so on. And, it turns out that visible light in the red bandwidth may stop pain to some degree.

The use of red light to reduce pain, inflammation and swelling and to promote wound healing has been known for almost forty years now when a scientist doing a laser experiment on mice discovered that the ones that were irradiated with a red laser grew their hair back faster. But how exactly does red light accomplish this? What are the mechanisms of action? And, can it be dangerous?

I’ll attempt to answer these questions in a way that hopefully makes sense.

When white light travels through a prism, it is dispersed into the colors of the visible electromagnetic spectrum; that is, the component colors that collectively comprise what the human eye perceives as white light. The component colors have wavelengths between about 380 nanometers (1 billionth of a meter long) to about 750 nanometers (nm) and are, from left to right: violet, blue, green, yellow, orange then red.

Just to the left of the visible spectrum is ultraviolet (UV) light and to the right is infrared light (IR); both of which are not visible to the human eye (although some animals can see IR).

spectrum

While the the therapeutic effects of red light are still being researched, there is evidence that light in this wavelength range (620-750+ nm) can in fact trigger physiological changes in cells, called photobiomodulation that have beneficial effects for injury healing and pain suppression.

The first law of photobiology says that for a low power visible light to have any effect on a living, biological organism the photons (light particles or energy units) must be absorbed by the organism via some type of molecular photo-acceptors, which scientists have given the name chromophores. (Photochem Photobiol. 2002 Aug;76(2):164-70). While the mechanism of action are still being researched, experiments show that human tissue absorbs visible light and undergoes biological changes as a result.

The Plant and Animal Connection

You probably forgot that you were introduced to the phenomenon of photobiomodulation way back in the 3rd grade. Remember in science class when you studied photosynthesis? The name says it all: photo (light) + synthesis (to make something out of other things). Sunlight strikes a plant leaf, gets absorbed by tiny structures in the leaf called chloroplasts which contain chlorophyll (the substance that makes plants green), which creates the energy the plant needs to convert carbon dioxide in the air and water into sugars for its food. Without sunlight, plants would starve to death, and so would every life form that depends on them.

Can it be that mammals have their own version of photosynthesis, or something similar to it? It sure looks that way, considering the tissue healing effects of red light.

How Red Light Influences Cellular Activity

The leading hypothesis of how red light creates photobiomodulation is by increasing cellular energy. Red light gets absorbed by a cell membrane enzyme (a protein) called cytochrome c oxidase, or cox for short. This enzyme influences the electron transport chain, the biological process that occurs in cell mitochondria and determines the rate of ATP (adenosine triphosphate) production and thus available energy in the cell.

Adenosine triphospate is every cell’s “fuel” molecule. Basically, cells trap free energy released from the breakdown (metabolism) of glucose– the basic unit of carbohydrates. The trapped energy is stored in the ATP molecule’s chemical bonds. Mitochondria are the structures in all animal cells where energy is created and can be thought of as the animal version of chloroplasts in plants. The energy released in the bonds of ATP molecules enables the cell to do the things it needs to do, such as repair membranes, remove waste and even multiply.

Another theory on how red light produces beneficial benefits is enhancing gene expression. More ATP production results in more reactive oxygen species production (ROS). In high concentrations this is bad, as excessive ROS can damage tissue and DNA (free radical damage). But with red light therapy ROS production is low level, local to the injury and has beneficial effects. ROS alters the cell’s state of oxidation, or redox state (basically, its electrical charge). Changes in a cell’s redox state induce intracellular signaling pathways such as nucleic acid synthesis, protein synthesis and enzyme activation. This activity then activates changes in transcription factors, which are the substances that up-regulate or down-regulate gene expression. Genes in DNA determine an organism’s physical features and influences its biological processes.

For example, red light activates factors involved in gene expression related to cell proliferation, remodeling, DNA synthesis and repair; ion channel and membrane potential, and cell metabolism. All these processes can benefit wound healing.

Proof of Red Light’s Healing Power

A 2014 Chinese study that involved compressing/ injuring spinal nerves in rats found that LLLT (Low Level Laser Therapy, which uses red and infrared light) “was able to enhance neural regeneration in rats following [the injury] and improve rat ambulatory behavior (ability to crawl and move).” The study’s authors concluded that the therapeutic effects of LLLT in this experiment may be exerted through suppression of the inflammatory response and induction of neuronal repair genes (increased expression of the genes involved in nerve repair). This suggests potential clinical applications for LLLT in the treatment of compression-induced neuronal disorders such as nerve root compression from disc bulges, stenosis and frank injury.

Another study concluded that low-level exposure to 980 nm laser light (near infrared) can accelerate wound healing. Exposure to low- and medium-intensity laser light accelerated cell growth in damaged fibroblast cells, whereas high-intensity light negated the beneficial effects of laser exposure.

So, it appears that the evidence on the therapeutic effects of red light therapy is convincing and the models appear plausible. More research is needed to get a better handle on how to best use light for therapeutic purposes. What we know is that light in the red visible spectrum (620-750 nm wavelength) and infrared (700 – 1000 nm) are preferred because they are better absorbed in human tissue. Shorter wavelengths (blue) scatter and are less absorbed. Red light is believed to be more appropriate for superficial areas (skin surface to a few millimeters below) because the light is quickly absorbed by the red hemoglobin of the blood and carried away; whereas the longer wavelength infrared (IR) and near infrared (NIR) light is appropriate for thick muscles and deeper joints since they are able to penetrate deeper into the body.

Factors that can influence therapeutic effect of red light besides wavelength include power output (watts), frequency, pulse rate, dosage and treatment area. Typical dosages used are 0.5 – 60 Joules/cm2, but there is no consensus among researchers on what constitutes the best dosage for any particular conditions.

Using Red Light Therapy

Red light can be delivered by “cold” lasers (lasers with minimal heat production) or diode (phototherapy) machines. The difference between the two is that lasers produce light of only one wavelength that is collimated (focused and organized), enabling deeper penetration but at a fixed depth and smaller area; whereas a red light diode generates a range of red light in different wavelengths, covering more area and depth levels due to the varying densities of human tissue (skin, fat, muscle, ligament, water).

Medical grade lasers and phototherapy devices can cost a few hundred up to thousands of dollars. These therapy devices can be found in some physical therapy, chiropractic and sports medicine clinics. There are low power, consumer level portable red light and infrared devices that get good results as well. Currently, I am not aware of any studies that compare the effectiveness of the expensive medical lasers with the cheaper consumer devices, but one must realize, light is light! If you have a soft-tissue injury or joint pain, I suggest you try a consumer level red light device before you try the more expensive options. They are available for sale direct to the consumer; no doctor’s prescription needed. So far, the studies indicate that red light therapy is safe to use although it is best to protect your eyes from scattered light during its application by wearing protective lenses.

The red light therapy device I use at home and on patients is the handheld red light therapy device, shown below:

tendlight

It is simple to use and gets surprisingly good results (and it doesn’t cost an arm and a leg). Use it for TMJ, epicondylitis, trigger points; pain in the hand and wrist joints and anywhere there is musculoskeletal pain and/or inflammation.

The Bottom Line: Yes, red light therapy can help heal injuries and lessen pain and is generally safe to use. This includes sprains, strains, bruises, burns and minor lacerations. You may even try it over your peri-orbital sinuses to help with tension headaces.

The ideal treatment protocols are not defined, but a good starting point is 2-3 minute applications of red light directly for every two square centimeters, twice a day.

Watch below how I use the red light therapy device to treat chronic tendonitis: