This section explores Light Therapy, the use of light for therapeutic benefits. For many applications, Light Therapy is a field of medicine considered to be Complementary and Alternative.
Complementary and Alternative Medicine (CAM) is defined by the National Institutes of Health (NIH) Center for Complementary and Alternative Medicine as, “those treatments and healthcare practices not taught widely in medical schools, not generally used in hospitals, and not usually reimbursed by medical insurance companies.”
See Complementary and Alternative Medicine (CAM)
Light therapy, or phototherapy, is used for the treatment of various medical conditions, including sleep disorders, depression, skin condition and wound healing. Aside from its use in skin conditions such as actinic keratosis which will not be covered here, light therapy has been found helpful treating depression and Seasonal Affective Disorder (SAD), a condition that occurs in climates with reduced sunlight at certain times of the year. Symptoms of SAD include fatigue, depression, hopelessness, and social withdrawal.
In patients with Alzheimer’s disease light therapy used to increase circadian stimulation during the day shows benefits for those with dementias living in long-term care facilities. A study found that Alzheimer’s patients exposed to a bluish-white light source during the daytime for 4 weeks significantly increased sleep quality, efficiency, and total sleep time and reduced their depression and agitation.
Pertinent to this website, there have been recent studies evaluating the use of light therapy for low back pain and fibromyalgia. The extent of light therapy’s clinical effectiveness and practical applicability remain somewhat unexplored but nevertheless light therapy is interesting and suggests potential usefulness.
Light Therapy – Pain
Light therapy may have psychological effects or physiological changes including the possible increased release of endogenous opioids which affect pain response or perception. Although few studies have investigated the effects of light therapy on pain, a recent clinical trial evaluated the effect of bright light exposure on nonspecific back pain. In this study, patients who received once a week light exposure for 3 weeks experienced reduced pain, suggesting a potential benefit for light in controlling pain.
Pain and Green Light
Recent research has examined the use of green light exposure to treat pain in animal and human studies. Additionally, there is some evidence that being present in environments that are rich in the color green (e.g., “forest bathing”) can decrease pain and have other health benefits. A pre-clinical study on rats found that whole body exposure to green light for eight hours produced analgesic and anti-hyperalgesic benefits that were negated by blocking the eyes from the green light. These effects involved descending pain inhibitory pathways and increased activity of endogenous opioids (enkephalins) in the spinal cord.
Green Light and Migraine Headaches
One of the unique characterizations of migraine headache is that they are frequently exacerbated by light. It has recently been found that green light exacerbates migraine headache significantly less than white, blue, amber or red lights. A 2016 study indicates that 80% of migraine patients describe an intensification of headache true for all colors except green, which affects only 40% of patients. Additionally, exposure to green light reduces pain intensity in 20% of the patients. The authors of the study also concluded that the impact of color on change in pain intensity is not dependent on the degree of intensity of the color. Another study evaluating glasses that filter blue light reduce migraine frequency (but not sensitivity to light) in children and that migraineurs are more sensitive to blue and red, as compared to green light.
Green light is least likely to exacerbate migraine headache and at low intensities it may even be therapeutic by reducing the headache intensity. Therapeutically, filtering out all but green light may reduce photophobia and headache intensity. The soothing effects of green are likely to involve a complex psychobiology
The mechanisms of light sensitivity appears to involve light-sensitive nerve receptors (cones) in the retina that activate nerve pathways to the thalamus area of the brain do so to a lesser extent than white, blue and red. Thalamic nerves are most responsive to blue and least responsive to green and cortical responses to green are significantly less than blue, amber and red lights. These findings suggest that migraine light sensitivity (photophobia) originates in cone-driven retinal pathways, modified by thalamic nerves and nerves in the cortex. Additionally, the findings provide substrate for the soothing effects of green light.
Green Light and Fibromyalgia
A recently published 2021 study found that green light therapy resulted in significant decreases in pain and opioid use in individuals with fibromyalgia exposed to green LEDs for 1 to 2 hours daily for 10 weeks. Additionally, the green light therapy improved their functionality and their ability to fall and stay asleep. It has been hypothesized that the rods and cones light receptors in the eyes play a role in the inhibition of pain pathways via the visual cortex.
Light Therapy – Overviews
- Bright light treatment of winter depression a placebo-controlled trial – PubMed – 1998
- Thin-film optical notch filter spectacle coatings for the treatment of migraine and photophobia – 2016
- Migraine photophobia originating in cone-driven retinal pathways – 2016
- Light Therapy Improves Sleep, Behavior in Alzheimer’s Patients
Light Therapy – Green Light
- Long-lasting antinociceptive effects of green light in acute and chronic pain in rats – 2017
- Shinrin-Yoku (Forest Bathing) and Nature Therapy – A State-of-the-Art Review – 2017
- Green Light Exposure Improves Pain and Quality of Life in Fibromyalgia Patients – A Preliminary One-Way Crossover Clinical Trial – 2021
Light Therapy – Red Light
- Development and Characterization of An Injury-free Model of Functional Pain in Rats by Exposure to Red Ligh – 2019
Emphasis on Education
Accurate Clinic promotes patient education as the foundation of it’s medical care. In Dr. Ehlenberger’s integrative approach to patient care, including conventional and complementary and alternative medical (CAM) treatments, he may encourage or provide advice about the use of supplements. However, the specifics of choice of supplement, dosing and duration of treatment should be individualized through discussion with Dr. Ehlenberger. The following information and reference articles are presented to provide the reader with some of the latest research to facilitate evidence-based, informed decisions regarding the use of conventional as well as CAM treatments.
For medical-legal reasons, access to these links is limited to patients enrolled in an Accurate Clinic medical program.
Should you wish more information regarding any of the subjects listed – or not listed – here, please contact Dr. Ehlenberger. He has literally thousands of published articles to share on hundreds of topics associated with pain management, weight loss, nutrition, addiction recovery and emergency medicine. It would take years for you to read them, as it did him.
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