This 2017 study (PDF) studied pain relief via photobiomodulation (PBM) in 49 mice. In order to provide pain relief, the researchers had to induce pain to relieve. So they injected each mouse in the abdomen with a 1% acetic acid solution (a diluted vinegar). This was enough to induce abdominal writhing, which the researchers took as evidence of the mice’s pain. They divided the mice into seven groups, one of which got no treatment for the pain, and six of which received laser or LED light at various frequencies for various periods of time. They counted how many times each mouse writhed. The mice that received the light treatments stopped writhing quicker than the untreated ones. Furthermore, the researchers were able to determine effective doses of PBM (wavelength and duration) for mice in pain. Frankly, I was uncomfortable reading this study because of the obvious suffering of the mice. But it may be good news for human pain sufferers because it suggests that, in the words of the study, “infrared light, laser or LED, under low doses and low irradiance seems the best option to solve acute pain.”
In fact, there is currently a clinical trial comparing pain relief from placebo PBM to actual PBM among 149 human adults. Rather than acute pain, this study is looking at chronic pain. That is to say, these people are not getting abdominal injections; they are volunteers who already suffer from low back pain. The researchers aim to gather “high-quality scientific evidence to support the effectiveness of this therapy in the treatment of patients with chronic low back pain, at short, medium and long term.” They expect to complete the study in April 2019.
Here’s how scientists believe PBM provides pain relief. Our cells have organelles that they use to do their work. One of these is the mitochondrion (plural mitochondria), whose job it is to generate ATP, a chemical that regulates metabolism, generates cell energy, and carries signals to other cells. Damage to the mitochondrion (regardless of cause) slows or even stops the production of ATP. I am simplifying things considerably here, but slowing the production of ATP slows cellular healing processes, increases oxidative stress, and allows inflammation. Infrared light at the right frequency seems to revive the mitochondrion and increase ATP production, as well as relaxing muscle cells. Increased ATP production reduces oxidative stress, swelling, and inflammation. It thus speeds the healing process. And muscle relaxation is itself a kind of pain relief. You can learn about the chemistry of all this from the video on this page.
We are almost a year away from the completion of the clinical trial that will provide better evidence of pain relief through PBM. But PBM has no side effects and is noninvasive, so there’s no reason not to try it if you think the experience of the injected mice holds promise for you. Over the course of several sessions, it could provide you with relief from whatever pain you have. A PBM session at Peak Recovery & Health Center usually takes 30 minutes, and many clients say they find it to be profoundly relaxing. Book a session now.
This photo may be what real pain relief looks like. It’s titled “Chiropractor” by Ryan Weisgerber. Creative Commons license.