Low-Level Laser Light Therapy - Potential Uses
by Evan McCarvill, ND
Melfort, Saskatchewan, S0E 1A0
The human body is a fragile thing, prone to acute injury, as well as to chronic degeneration as we age. In medicine, there are certain things we can do to accommodate an injury, such as disinfecting it, providing a dressing, supporting a broken bone with a splint, taking pressure off achy knees with a cane, etc. But beyond these basic support strategies, we can usually do no more than wait for the body to complete its own healing.
As efficient and miraculous as the body’s innate self-healing capacity is, it does seem to have its limitations, especially as we age. We tend not to bounce back from injury as easily as when we were younger, and our weight-bearing joints (low back, hips, knees, ankles, etc.) are prone to chronic degenerative pain with osteoarthritis.
But what if there was a therapy that has been shown to jump-start the cellular mechanisms that drive inflammation and tissue healing? What if there was a way to measurably speed up recovery from acute injury, to enhance healing of surgical wounds, to resolve diabetic ulcers, or to mitigate or even reverse chronic degenerative joint pain? Well, there is! It’s called “low-level laser therapy,” or sometimes “cold laser therapy.”
What Is Laser Therapy?
Don’t let the name throw you: We are not talking about some kind of harsh-cutting laser or some kind of destructive sci-fi laser gun. A laser is simply a form of light emission that is highly coherent and focused, enabling it to shine noninvasively through multiple layers of tissue, to deliver its healing effect to the site of injured or stressed tissue cells.
The wavelength is also something to consider, in terms of safety. If the light has a very short wavelength, which is another way of saying it has a high frequency, then it can be destructive to living tissue. Examples of this would be UV radiation or gamma radiation: These are called “ionizing radiations,” because the highfrequency photons have enough energy to blow electrons off of the molecules that build your cells, thus breaking their bonds and causing damage. This is why skin can burn in the sun, or why gamma rays can cause radiation poisoning. Such light frequencies are above and beyond the range of the naked human eye, so we can’t see them directly.
However, the light used in cold laser therapy is nothing of this sort. It has relatively long wavelengths, or low frequencies, ranging from what we perceive as “red” light, down to below the human eye’s perceptual range, also known as “infrared.” This is nonionizing radiation, and these frequencies are not at all damaging to living tissue, but as we’ll discuss, can have therapeutic effects.
Brief overview of LLLT
Light exposure has a long history as a treatment modality for healing. In Ancient times, as far back as 1400 BCE, sunlight was thought to have therapeutic value for a variety of diseases. Sunlight exposure for healing purposes was called “heliotherapy.” Much later, the Scandinavian doctor Niels Finsen, who’d used sunlight exposure to treat some of his own health issues, was researching the potential of ultraviolet light therapy for such conditions as measles, smallpox, psoriasis, and vitiligo, toward the end of the 19th century.
The “father” of modern low-level laser therapy (LLLT) was the Hungarian physician Dr. Endre Mester, who published his first paper on the stimulating effect of laser light on rat skin cells in 1966, and another paper on the stimulation of wound healing with light in 1969. Since that time, over 3000 publications with over 150 positive clinical doubleblind trials have been published to date. Low-level laser light therapy is also known as “cold laser therapy,” but also sometimes as “phototherapy” or “photobiostimulation.” This form of therapy is noninvasive, pain-free if properly applied, and—as we’ll discuss— quite effective in many stubborn cases.
Mechanism of Action
To exert a photochemical healing effect, light must be absorbed by a photoreceptor molecule within the tissue’s cells. Plants have capitalized on this mechanism beautifully, using highly specialized molecules such as chlorophyll and carotenoids to capture solar energy for their basic metabolism. In animals and humans, there is some debate as to what this molecule could be. Some researchers suggest that the light is absorbed by the outer cell membrane, which then triggers an internal signal cascade within the cell. Another leading contender is the cytochrome series of molecules, which are involved in energy production for our cells through organelles called mitochondria. When photons are thus absorbed by our mitochondria, they can generate more energy for the cell to use for its activities, including healing and replication for restoring a damaged tissue.
The most critical changes observed in tissues during laser therapy are increased cell replication, increased cell motility or movement, increased cellular metabolism, increased healthy blood-vessel production, stimulation of the immune response, and mobilization of white blood cells. In other words, it tends to jump-start the natural inflammatory response to an injury and pushes it to its natural conclusion, which is the restoration of healthy tissue. Interestingly, it has been observed that cells which are starving or otherwise under stress tend to respond more readily to the laser therapy than cells which make up healthy unstressed tissue.
There are a few safety considerations for laser therapy. If you’ve ever sat in an infrared sauna while wearing metal jewellery, then you can attest to this. Metal heats up when exposed to infrared radiation of the sort that laser therapy uses. Therefore, metal jewellery such as rings or necklaces should be removed, if that is the part of the body to be treated. Similarly, your practitioner should be informed of any metal implants or joint replacements you may have, so that they may also be avoided. In addition, tattoos are metal-based, and should be avoided for the same reason.
Other contraindications would include direct irradiation over the womb or low-back area during pregnancy, directly over the site of a malignancy, or direct radiation of the eye or thyroid.
However, there are no concerns in cases of pacemakers, epilepsy, or nonmetal prosthetics.
Factors of Effectiveness
In practical terms, certain factors play into laser therapy’s effectiveness. Firstly, there is the dose to consider, measured in joules per centimetre: The greater the dose, the more likely a physiological response. Care should be taken, however, not to give too big of a dose, or else the inflammatory response may become overstimulated, and this can result in pain and aggravation of the injury. Therefore, treatments usually begin at a relatively low intensity, and the intensity is conservatively increased, over the course of multiple treatments, according to the patient’s response.
Some injuries resolve after only one treatment. Usually, these rapid recoveries are for relatively minor acute injuries in younger people. However, most conditions, especially chronic, long-standing, degenerative problems, take several repeated treatments to show a response. There is a latency period of up to seventy-two hours, where the cells remain stimulated from the previous light treatment. It is usually a good idea to build upon this excitation, by coming in for treatments in close succession, within seventy-two hours or even forty-eight hours of the previous treatment, rather than waiting, say, a week or more. If you wait too long, you will just be stimulating cells from their baseline level of activity, and will see slow or nonexistent progress. But treatments given in close succession quickly show a response, and it is at that point that treatments can be tapered off.
Age is another factor to consider. As I mentioned above, younger people tend to respond more rapidly. This is because the mitochondria of their cells are still running very efficiently, and thus readily respond to the light stimulation. However, as we age, our mitochondria become more “leaky” and less efficient. Factors like good nutrition and regular exercise can help to preserve our mitochondrial efficiency, by the way, and so can laser therapy. With each successive treatment, cellular activity becomes more energized, and healing can take place.
Additionally, patients who are overweight will have more adipose (fat) tissue for the light to pass through, and so can require more intense treatments and longer treatment times. Similarly, patients with darker skin tones, by definition, have more melanin in their skin, which tends to block the light emission, and so can also require more intense treatments or longer treatment times.
So, allow the above factors to inform your expectations, if you think laser therapy may be helpful for you. Even if there are obstacles to overcome, it is simply a matter of applying the treatments with the appropriate effort to get results.
Here is a short list of conditions and symptoms that might appropriately call for low level laser therapy:
Reduces pain in cases of acute or chronic injury to nerves, soft tissue, muscles, tendons, joints, and bone (e.g. osteoarthritis, low back pain, sciatica).
Reduces swelling in cases of acute injuries of superficial muscles, tendons, ligaments, and bursae (e.g. sports injuries, tennis elbow / tendonitis, sprained ankle, rotator cuff injury).
Improves wound healing in slow-to-heal or nonhealing wounds of soft tissue, tendons, and bone (e.g. diabetic ulcers, surgical sutures).
Improves absorption of interstitial fluid, to increase lymphatic circulation and drainage, and thus promoting better tissue recovery (e.g. chronic venous insufficiency, leg swelling).
Improves local and systemic blood circulation, making it useful for conditions such as Raynaud’s disease and torpid leg ulcers.
Enhances autoimmune responses in immune-deficient conditions, such as psoriasis, rheumatoid arthritis, and atopic dermatitis.
Low level laser therapy now has a long-established history of use in alternative medicine practices. It has been shown to be safe and effective in a wide variety of cases. If you think you may benefit from LLLT, talk to your practitioner to see if it is right for you.