I recently finished a helpful book giving an overview of the benefits of red light therapy and how to go about it with regard to dosing, the suitability of what's currently on the market, etc. The book is called
Red Light Therapy, by Ari Whitten, who is an energy and fatigue specialist with a BSc in Kinesiology, a PhD in Clinical Psychology, and 2 advanced certifications from the Nat’l Academy of Sports Medicine. He hosts a podcast on his website.
Bioactive Light and Human Health
Whitten does a brief overview of the most well known types of bioactive light in humans:
Blue light (450 - 495 nm) —sets the circadian rhythm in our brain, which in turn regulates numerous different neurotransmitters and hormones. Increases cortisol.
UV light (300-400 nm) —allows us to synthesize vitamin D from the sun.
Far-infrared (>1000 nm)—acts to heat up our cells (this is the part of the sun’s spectrum that you feel as heat) which stimulates changes in cell function, as well as circulation changes.
Red light (630-680 nm) and
near-infrared light (800-880 nm)—act on the mitochondria in our cells to stimulate increased cellular energy production and stress resilience.
This is an incomplete list of all the effects of each obviously. Elliot has a more comprehensive video on this
HERE. A good interview with Dr Alexander Wunsch discusses more about the benefits of dosing sunlight for vitamin D is available
HERE. Anyway back to the book and its discussion about mal-lumination.
List of diseases linked to lack of sunlight:
-neurodegenerative diseases like Alzheimer's, dementia, Multiple Sclerosis, Parkinson's.
-cancer
-obsesity, diabetes, and metabolic syndrome
-heart disease.
List of diseases or negative outcomes linked to artificial light exposure at night:
-cancer
-depression
-fat gain, obesity, diabetes, metabolic syndrome
-insomnia and poor sleep quality
-mood disorders
While many light frequencies have various beneficial effects when in the right proportion, the book focuses on Red and NIR light (obviously) and how they specifically benefit the human body.
Molecular Mechanisms of Red and NIR Light's Action
Red and NIR light chiefly benefits us through two mechanisms: increasing mitochondrial energy production, and hormetically up-regulating the cell's antioxidant and antinflammatory defense systems. The author also mentions two poential mechanisms which are less definitvely proven but exist as possibilities.
Increasing Mitochondrial Energy Production
R/NIR light increases mitochondria energy production by being absorbed by cytochrome c oxidase: one protein complex in the electron transport chain that converts oxygen to water in order to drive ATP production in the cell. The performance of cytochrome c oxidase can often be inhibited by increased amounts of nitrous oxide in the cell, which is an essential signalling molecule but which binds and inhibits cytochrome c oxidase's ability to bind and reduce oxygen. Red and NIR light essentially knocks nitrous oxide off of cytochrome c oxidase, allowing it to properly bind and reduce oxygen. Shining rea and NIR light on the body directly improves the mitochondria's ability to generate energy for the cell.
Hormetic Up-Regulation of Cytoprotective Genes
Red and NIR acts as a low-level stressor on the mitochondria also, by increasing the amount of reactive oxygen species therein. This causes the mitochondria to signal to the cell nucleus to up-regulate antioxidant and anti-inflammatory pathways to quench the free radicals and inflammation. This results in a net increase in the activity of these these protective measures, improving the cell's ability to deal with similar stressors. Some have even called red and NIR light an exercise mimetic, because exercise itself stimulates these same cellular pathways in response to reactive oxygen species and inflammation.
Fourth Phase of Water (?)
One of these was related to Jack Pollack's on the fourth phase of water, and that red and NIR light may charge the structured water battery in cells and tissues for whatever kinetic or chemical reactions they facilitate.
Photosynthesis (?)
At least one study has found that mammals are capable of taking up chlorophyll metabolites into the mitochondria and using them to generate ATP. This mechanism is chiefly involved in the regeneration of CoQ10: a prominent antioxidiant and cofactor in facilitating electron transport in the mitochondria. When doing this work it converts from its active and reduced form (ubiquinol) to its oxidized and inactive from (ubiquinone), which itself needs to be regenerated back into ubiquinol to help the mitochondria or quench free radicals. It was found that mixing the inactive form with chlorophyl metabolites (the kind the mitochondria incorporate) and shining red or NIR onto it converted CoQ10 back into its active form. What's also interesting is that CoQ10 can be transported via the bloodstream to cells and tissues deficient in it. This allows the regenerated CoQ10 in our skin and organs closer to the skin (given they receive healthy amounts of R/NIR light) to permeate deeper tissues and so improve the mitochondrial function of more of our body.
Effects of Red and NIR Light
I'll use his own words here:
Cellular Benefits
Inflammation: One of the most important cellular mechanisms that red/NIR light have is their effect on inflammation pathways. It appears to do this through inhibition of inflammatory prostaglandin PGE2 production and expression of COX-1 and COX-2, as well as inhibition of the NF-kB pathway. The net effect: Reduced inflammation.
Cytoprotection: Various studies have shown that red/NIR light can help protect cells from dying after being exposed to various toxins (e.g. methanol, cyanide, etc.). It appears to have cell-protective effect in some instances.
Proliferation: Some types of cells (e.g. skin cells, bone cells, cells that line blood vessels, etc.) have been shown to grow and replicate faster with exposure to red/NIR light.
Migration: Some types of cells (e.g. tenocytes in tendons or melanocytes in skin) need to actually move to get to the location they’re needed. Some research has shown that red/NIR light can stimulate this.
Protein Synthesis: Red/NIR light can also stimulate cells (e.g. skin cells, bone cells, etc.) to produce more proteins (e.g. collagen). Stem Cells: Stem cells are apparently even more sensitive to red/NIR light. Red/NIR light has been shown to positively affect growth, movement, and viability of stem cells. This may be relevant to both stem cells already present in our body, as well as in the context of stem cell therapy.
Tissue Benefits
Muscles: Numerous studies have shown that red/NIR light affect muscle performance, recovery from exercise, and adaptations (i.e. enhanced strength, endurance, muscle growth, fat loss) to exercise. (These studies are discussed in this book in later sections.)
Brain: Red/NIR light has been shown to benefit brain function as well. Studies have shown improvements in cognitive performance and memory, improved functioning after traumatic brain injury, improved mood, as well as improvements in certain neurological diseases (e.g. Alzheimer’s disease). The improvements in mitochondrial function, reduction in inflammation, and increased Brain-Derived Neurotropic Factor (BDNF) likely all play a role in enhancing neuron health.
Nerve (Pain): Some studies have shown that red/NIR light can dull pain due to blocking conduction at nerve fibers. Anti-inflammatory actions, as well as blocking of substance P, likely play a role in this effect.
Healing (Bones, Tendons, and Wounds): Numerous studies have shown that red/NIR light can stimulate and accelerate healing of numerous types of injuries—from tendon/muscle/ligament tears to bone fractures, and skin wounds. This is likely by affecting local growth factors involved in cellular repair, as well as effects on the inflammatory processes.
Hair: Red/NIR light is also used in the context of hair re-growth, and numerous studies have shown it to be effective for this purpose. This is likely due to local blood vessel dilation and anti-inflammatory effects.
Skin: Numerous beneficial effects on skin wrinkling and laxity, cellulite, collagen production and other aspects of skin health have been found. Anti-aging of the skin is one of the most common uses for red/NIR light.
Fat: The exact mechanisms of how this happens are still debated among researchers, but numerous studies have shown that red/NIR light can stimulate the release of fatty contents from fat cells, and ultimately, lead to body fat loss.
The extent to which the mitochondria's function affects our overall health cannot be overestimated, and the same goes for red and NIR light exposure:
-Anti-aging effects in the skin and hair (enhancing collagen synthesis, production, and elastin production for youthful skin and dramatically reducing cellulite)
-Lowering inflammation
-Enhancing fat loss
-Enhancing physical performance and muscle recovery afterward
-Boosting testosterone
-Speeding wound healing
-Spurring neurogenesis in the human brain, strengthening synapses, spurring brain cell growth
-Helping prevent cognitive decline
-Reducing waist circumference and liberating fat from cells so it can be burned again
-Enhancing physical performance and muscle recovery afterward
-Enhancing fertility
-Combatting gingivitis and promoting healthy gums
-Enhancing stem cell implantation and proliferation63 Enhancing gland health from the thyroid to the lymphatic system
-Clearing skin for sufferers of acne, rosacea, eczema, psoriasis Improving eye health
-Fighting chronic fatigue and fibromyalgia
-Potentially helping the body to fight cancer (in tandem with chemotherapy)6
-Removing wrinkles, lines, and veins on the surface of the skin
-Increasing energy
-Improving the appearance of scars
-Killing pain
-Protecting cells against damage from stress
The author devotes large sections toward talking about the specific clinical benefits of red and NIR light on fibromyalgia, hashimoto's disease, cancer, bone healing, inflammation-linked diseases, eye health, depression/anxiety, fat loss, and many others.
Guide to Dosing Red Light Therapy
A Brief Note on the Bimodal Response
The most important point when it comes to dosing red and NIR light is that the human body has a biomodal response to R/NIR dosing. Too little produces few effects, and too much can actually reverse the beneficial effects and be inhibitory or harmful. Harm can come from excess R/NIR light via excess production of reactive oxygen species, excess shunting of nitrous oxide from the mitochondria into other cellular pathways, and may induce apoptosis in weak or ailing cells which may have recovered. So there is a sweet spot to dosing that one needs to achieve for optimal benefits.
The most important things to consider for dosing are
-distance from the light
-wavelength of the light
-actual wattage of efficacious frequencies (which can be quite different from claimed -wattage)
-size of the device or treatment area
Power and Dosage
Dose = power density x time, which is in units of energy (joules). Eg, 100 W/cm^2 shone for 10 seconds gives 1 J/cm^2. This energy will be distributed in a decreasing gradient from the skin inwards.
This energy dosage decreases with distance from the light source. A 100 W/cm^2 light source may drop to 90 at 6", 60 at 12", 40 at 18", etc. Closer allows a higher dosage over a small area, and farther allows a lower dosage over a wider area. Most red and NIR devices provide information about the wattage per cm^2 based on distance. A power of at least 30 mW/cm^2 is recommended by the author at least, and often 100mW/cm^2 at 6" away is optimal, since doing it from farther away offers more energy. A device that emits a quarter of the irradiance will require using it for four times as long to produce the same effect.
Dosing for Skin
The optimal dosage is between 3 and 15 joules. Because of the low dosage required, it is better to use from farther away when using high power devices, so as not to exceed to maximum beneficial dose. On one 100W/cm^2 device it works out roughly to 1-4 minutes from 12" away, 1.5-5 minutes from 18" away, or 2-8 minutes from 24" away.
Dosing for Deeper Tissues and Organs
This may vary a lot more, depending on the depth and obstructions, but the author recommends 10-60 J. To emphasize, it is better to be conservative since the immediate large benefits give way to diminishing returns, and then inhibition. The higher dosing requirements also mean that a closer, high-powered light is recommended such as the 100 W/cm^2 device at 6" for 2-7 minutes or at 12" for 5-10 minutes.
Penetration Depth
Penetration depth varies with tissue type (denser tissues absorbing more light), power of the device, its distance from the body, and wavelength. For the latter, it is measured by the distance within the body after which the light intensity decreases to 1/e (~37%). For red and NIR light this technically is 3-6mm, but since the power level decreases fractionally the light still produces benefits as deep as 5cm into the body. In terms of practical benefits they can still be conferred at 2 inches of depth.
In one study it was found that NIR penetrates much deeper than red light, and was found to penetrate as much as 4cm into the head, passing the skull and meninges and reaching the brain. Because red light does not penetrate as deeply as NIR, it is better suited for delivering energy to the skin, where most of the energy of red light will be absorbed. NIR light is better for reaching deeper into organs and muscles, since less of it is absorbed at the skin level.
Other differences between red and NIR light:
-Red light is visible to the human eye.
-NIR typically has much stronger irradiance per LED bulb than red.
-most companies charge more for having more NIR LEDs than a mixture of NIR and red LEDs. Pure red lights are often cheaper.
Most red light therapies of a mixture of the two types, but having a specific aim lets you fine tune which frequency range you can best use: red (630-680 nm) or NIR (800-880 nm).
A Word on Infrared Lamps
Many heating IR lamps (1500K) contain some red and NIR light, but since that is not the chief purpose of these devices a much smaller percentage of their power output is in the 630-680 and 800-880 nm therapeutic ranges - sometimes as low as 15%.
Recommended Devices
Whitten says outright that it is better to invest in medium- or large-size devices, since their power and spread will make dosing the body much easier. He had a top 5 list, and said he arranged discount codes with manufacturers for readers interested in buying, so FWIW:
His recommended medium devices:
-Red Rush360 by RedTherapy.co (360 watts, 100mW/cm^2 at 6", 16.3" tall by 10.6" wide, $450)
-BIO-300 by Platinum Therapy Lights (300 watts, almost 100mW/cm^2, 19" tall by 9" wide, $450
-Joov mini (which on paper is less powerful and more expensive than the others so I'm not sure why he recommended it, other than it's an old brand with at least a well established reputation.)
His recommended larger devices:
-BIO-600 by Platinum Therapy Lights (600 watts, over 100mW/cm^2, 36" tall by 8" wide, $750
-Joov Original Light by Joov (300 watts, about 70mW/cm^2, roughly same dimensions as BIO-600, $1000
Full body devices:
-Joov Max by Joov (960 watts, 4.5' x 16", $2400-$3000
)
-setting up two Red Rush 360s or Platiunum BIO-300s and using them side-by-side
Misc. Comments from the FAQ
Some misinformation abounds stating to the effect that only laser R/NIR lights are effective. This came about because many studies have ran tests using low level laser therapy. Over 250 studies have shown LEDs have been found to be just as effective.
The best time of day to do it is based on aims. The time of the day for the most part does not matter, and the benefits are more about getting an edge before an activity.
-for cognitive benefits, at the start of the day
-for enhancing physical performance, 5-60 minutes before the activity
-for fat loss or muscle gain from exercise, before or after
-to speed recovery, after
Rates of improvement based on consistent use of R/NIR light
-pain; 20 minutes
-cuts or injuries; variable (heals much faster)
-hair loss; several weeks or months
-arthritis, a few weeks or months
-cellulite reduction; a few months
-wrinkle reduction and anti-aging; a few weeks
While benefits to eye health have been found for exposure to R/NIR light using LEDs, using a laser light is a very bad idea. Aside from that excessive exposure may cause the same drawbacks as other tissues vis-a-vis the bimodal response. Less than 5 joules is more than a suitable dose for eyes.
R/NIR usually does not penetrate through clothes, so get in your nickers or the birthday suit if using a full-body light.
For pregnant women, there is insufficient data on the effects of R/NIR light on the fetus. In theory other parts of the body should be okay (consult your doctor!)
If you notice any strange or negative effects, including fatigue, lower the dosage.
The book on the whole made me curious about how to quantify the power of the infrabed and its LED array, to see where it fit with regard to the recommended dosages and so on. I've also decided to obtain some chlorophyll supplements and see if it makes a difference in red light therapy.
