Chronic pain afflicts over 100 million people across the United States. It diminishes their productivity and their quality of life and costs hundreds of billions of dollars each year to medically manage. It shatters people’s emotional wellbeing, tears apart families and claims lives through suicides and accidental drug overdoses
Green LED (light-emitting diodes) therapy may represent a novel, nondrug strategy for managing pain, with important implications for patients with fibromyalgia.
Treatments for chronic pain are inadequate, and new options are needed. Nonpharmaceutical approaches are especially attractive with many potential advantages including safety. Light therapy has been suggested to be beneficial in certain medical conditions such as depression, but this approach remains to be explored for modulation of pain.
We investigated the effects of light-emitting diodes (LEDs), in the visible spectrum, on acute sensory thresholds in naive rats as well as in experimental neuropathic pain. Rats receiving green LED light (wavelength 525 nm, 8 h/d) showed significantly increased paw withdrawal latency to a noxious thermal stimulus; this antinociceptive effect persisted for 4 days after termination of last exposure without development of tolerance.
No apparent side effects were noted and motor performance was not impaired. Despite LED exposure, opaque contact lenses prevented antinociception. Rats fitted with green contact lenses exposed to room light exhibited antinociception arguing for a role of the visual system. Antinociception was not due to stress/anxiety but likely due to increased enkephalins expression in the spinal cord. Naloxone reversed the antinociception, suggesting involvement of central opioid circuits. Rostral ventromedial medulla inactivation prevented expression of light-induced antinociception suggesting engagement of descending inhibition.
Green LED exposure also reversed thermal and mechanical hyperalgesia in rats with spinal nerve ligation. Pharmacological and proteomic profiling of dorsal root ganglion neurons from green LED-exposed rats identified changes in calcium channel activity, including a decrease in the N-type (CaV2.2) channel, a primary analgesic target. Thus, green LED therapy may represent a novel, nonpharmacological approach for managing pain.
Early research using green light-emitting diodes (LED) is showing some promise in rats as a novel, non-pharmacological approach to managing pain. And researchers are excited enough to start a human clinical trial for people with fibromyalgia.
Researchers at the University of Arizona had results of their study published in the February 2017 issue of the journal Pain.
In the study, rats with neuropathic pain showed more tolerance for thermal and tactile stimulus when bathed in green LED compared to rats with neuropathic pain that were not exposed to the greed LED.
Chronic pain refers to pain that typically lasts for more than three months or past the time of normal tissue healing, according to the Centers for Disease Control and Prevention (CDC). Chronic pain can be the result of an underlying medical disease or condition, injury, medical treatment, inflammation, or an unknown cause.
The prevalence of chronic pain varies, but according to CDC estimates, 14.6 percent of adults in the United States have current widespread or localized pain lasting at least three months.