We already know that red light therapy, also known as photobiomodulation or low-level laser/light therapy (LLLT), enhances overall wellness and is effective in treating numerous physical conditions.
Through mitochondrial stimulation and the natural increase in cellular energy produced by red light therapy, inflammation is reduced, circulation is improved, stem cell production is activated, and your body’s natural ability to heal itself is kicked into high gear. The benefits are seemingly endless: anti-aging, relief from skin conditions, pain management, accelerated wound healing, better athletic performance, weight loss assistance, and cellulite reduction, just to name a few.
But, can red light therapy have a significant impact on brain health? The science says yes. Significant clinical research shows that red light therapy can have as significant an impact on your brain cells as it does on any other cells in your body.
Michael Hamblin, PhD., Associate Professor at Harvard Medical School and avid LLLT researcher, is quoted as saying: “Near-infrared light can penetrate quite deep into the body. So if you shine it on your head, it will penetrate your skull and quite a lot of it is absorbed by your brain. Once you understand this, it’s amazing to think of the various diseases of the brain that need regeneration and healing, which could potentially be treated with light therapy.”
In this article, we will discuss what red light therapy can do for your overall brain health, your mind, and your psychological well-being.
Table of Contents
Can Red Light Really Penetrate Your Skull?
Yes. Near-infrared (NIR) light emitted from a powerful, high-quality device can penetrate your skull up to five centimeters (cm), which is almost two inches. These wavelengths provide the same energizing properties and healing benefits to your brain cells that they do to the cells in the rest of your body.
Because the red light needs to be powerful enough to penetrate your skull to provide any benefit to your brain, the irradiance level of your device is significant. “Irradiance” refers to the power density of the light emitted over a given area of its target (not the power of the light at its source). Light irradiance is measured in milliwatts per square centimeter (mW/cm²). If the irradiance of a device is too low, the level of cellular penetration will be inferior and likely not be sufficient to penetrate your skull.
Keep in mind that the further you are from the light source, the lower the level of irradiance you will experience. This is governed by a mathematical property known as the inverse square law, meaning that light irradiance at a certain distance from a device equals the inverse of the square of the distance from the source. For example, if the device is three times as far away, the light will be one-ninth as intense as it was at its source. For this reason, it is important to be aware of the manufacturer’s recommended minimum usage distance. By following this recommendation, you will be sure to experience the maximum possible level of irradiation.
For red light brain therapy, the higher the power density/irradiance numbers, the better. Most light therapy devices have power output readings ranging anywhere from 20 to 200 mW/cm². To ensure the deep cellular penetration required for red light brain therapy, using a device with a high irradiance reading as close to 200 mW/cm² as possible is recommended. The higher the irradiance level, the more efficiently the light can penetrate your skull to reach your brain cells. An irradiance level of 100 mW/cm² or less has little chance of penetrating sufficiently.
Most manufacturers openly disclose the testing procedures and resulting irradiance readings of their devices. If that information is not readily available, you can always email the manufacturer and ask questions. Be aware, though, that if no irradiance readings are listed, this can be a red flag. The manufacturer might not want you to know the irradiance reading if it is low. Reputable manufacturers are aware that irradiance is an important factor in the therapeutic power of a device and will openly provide this data to consumers.
Wavelength or frequency is equally as important as irradiance when it comes to red light therapy for your brain. Red light-emitting diode (LED) light is only capable of penetrating your body to a depth of about 10 millimeters (mm). It is important to make sure your device can also administer NIR light to reach the depth of penetration necessary to effectively reach your brain cells.
When administered by a high-quality, high-irradiance device, red NIR light can replenish and regenerate your brain cells and tissue. Cerebral blood flow is increased and oxygenation is elevated, allowing your brain to function more efficiently and heal itself if necessary. Oxygen is necessary to your brain so that it can signal the rest of your body as to which muscles and tissues are in need of blood flow. Increased blood and flow and oxygen to your brain help your entire body function more productively.
The ABC’s of Brainwaves: How Do Our Brains Work?
To fully comprehend how red light therapy can benefit your brain, it is helpful to gain an understanding of basic brain function.
All of our thoughts, behaviors, and feelings are generated by the neurons within our brains communicating with one another via neural pathways (synapses). Electrical pulses emitted by our neurons during this communication process create brainwaves.
The frequency of brainwaves can be high, low, or anywhere in between, and will vary based upon our actions and emotions at any given moment. When we feel super-charged, hyper-energized, confused, hysterical, frenetic, or panicked, our brainwave frequencies are at their highest. When we feel sleepy, sluggish, lethargic, depressed, or fatigued, our brainwave frequencies are very low.
Brainwave speed is measured in Hertz (Hz), or the number of cycles per second. Brainwave speeds are classified into six basic categories based upon speed.
Infra-Low Waves (less than 0.5 Hz)
Also known as Slow Cortical Potentials, Infra-Low brainwaves are the slowest of all. These are the only brainwaves that are completely innate and function independently of external stimuli. Infra-low brainwaves are intrinsic, rhythmic electrical vibrations in the cortex of our brains that control our basic brain functions. Less is known about infra-low than about brainwaves that measure higher in frequency. This is mainly because higher frequencies are easier to detect, measure, and record.
Delta Waves (0.5 to 3 Hz)
Delta brainwaves are deep and rhythmic, resembling a low, steady drumbeat. Delta waves put our external consciousness on hold and allow for deep, restorative sleep. Like infra-low waves, delta brainwaves are more innate and less regulated by external forces or awareness.
Theta Waves (3 to 8 Hz)
Theta brainwaves are also characteristic of sleep, but not the deep, dreamless sleep of Delta waves. Theta waves are more common during the rapid eye movement (REM) sleep phase when our senses are still focused inward instead of on the external world, but our minds are nevertheless active. This is when we dream in vivid detail and have a heightened sense of internal awareness and intuition. If you have ever gone to bed with a problem on your mind and woken up with a solution, you likely have Theta brainwaves to thank for your nocturnal problem-solving skills. The Theta brainwave phase is also where our brains house our personal fears and issues; the ones we ruminate on.
Alpha Waves (8 to 12 Hz)
Alpha brainwaves occur when we are at peace and “living in the moment”. Alertness, serenity and a general feeling of restfulness and satisfaction characterize and generate Alpha brainwaves. This range of frequency is common when you are deep in thought, feeling creative, and are focused on doing something intricate that you enjoy.
Beta Waves (12 to 38 Hz)
Our normal state of being awake, alert, and engaged in normal thinking processes and problem-solving generate Beta brainwaves. Beta waves are essential for focus and logical thinking; however, on the higher end of their frequency range, they are also associated with stress. At this level, Beta brainwaves can hinder productivity and creativity.
Gamma Waves (38 to 42 Hz)
Gamma waves have the highest frequency of all brainwaves. They are conducive to the concurrent processing of multiple pieces of data. Different areas of your brain are communicating rapidly and efficiently with one another. Gamma brainwaves are associated with deep thinking and high levels of concentration. On the downside, very high-frequency brainwaves can also be associated with feelings of frenzy, over-excitement, stress, and chaos.
Our brainwaves flow in direct proportion with our psychological and physical experiences of the world around us. If our brainwaves are off-balance, our thoughts, emotions, and behavioral choices are affected. Overstimulation in certain areas of the brain is tied to depression, anxiety, sleep disorders, agitation, aggression, and even chronic nerve pain. Unstable brainwave activity can cause conditions like bipolar disorder, obsessive-compulsive disorder, panic attacks, and seizures.
Red NIR light therapy has been proven to enhance the instance of Delta, Theta, and Alpha brainwaves and reduce the instance of Beta brainwaves. [1] This allows your brain to function at a higher cognitive level and perform more efficiently.
Red light therapy has also been shown to increase your ability to [2]:
- Organize
- Prioritize
- See tasks through to completion
- Set and achieve goals
- Process, understand, and regulate emotional responses
- Empathize
- Control impulses
Red light reduces oxidative stress, improves metabolic function, and it protects neurons from deterioration and damage. New neurons and new synapses (neural pathways through which neurons transmit information) are generated, allowing for more efficient overall brain function and better potential for healing.
How Does Red Light Therapy Enhance Your Mind and Cognitive Abilities? What Neurological Conditions and Diseases Can It Treat?
Red light therapy can benefit a healthy brain, an injured brain, and even help treat mental health conditions and degenerative neurological diseases.
With a better grasp of brainwave and brain function basics, we can now explore the wide array of applications for which red light therapy can improve overall brain health.
Cognitive Ability, Mental Sharpness and Acuity
Even a healthy brain does not consistently function at its greatest potential. Clinical research shows that red light therapy can enhance:
- Memory
- Concentration
- Focus
- Problem-solving and reasoning skills
- Learning ability
- Reaction time
- Overall mood; you think more clearly in general when you are in a good mood
One of the first red light studies performed on human subjects (rather than animals) with regard to cognitive function concluded with the treatment group exhibiting more positive emotional states, better moods, memory improvement, and quicker reaction times as compared to the placebo group. [2]
A study on mice showed marked increases in memory and learning ability after receiving red light therapy. [3]
Another study performed on healthy human subjects performed event-related tests and evaluated responses before and after red light therapy. Results showed significant improvement in cognitive measures and reaction times in the treatment group, but not in the control/placebo group. [4]
Red light therapy provides a means of accessing your brain’s untapped potential and capabilities.
Post-Traumatic Stress Disorder (PTSD) and Gulf War Syndrome
PTSD can occur if you have experienced a shocking, dangerous, scary, traumatic event. The fear and immediate reaction generated by the event lingers and is re-experienced even when you are no longer threatened or in danger.
“Gulf War Syndrome” is similar to PTSD in that it is caused by traumatic events that create lasting effects; however, it also has a real physical impact. At least one-fourth of 1991 Gulf War veterans are afflicted by a range of unexplained symptoms including chronic headaches and respiratory disorders. The exact cause of Gulf War Syndrome remains undetermined, but it may be the result of exposure to harsh chemicals and pesticides.
Research shows that PTSD symptoms decline with the use of red light therapy. Studies have focused on accident victims with PTSD, war veterans, and subjects with depression and anxiety-induced PTSD from various past events. [5] [6] [7]
The study of red light therapy as it applies specifically to Gulf War Syndrome is just beginning, but the first two Gulf War veterans studied reported a marked reduction in symptoms after undergoing treatment. [8]
Mental Illness and Psychiatric Disorders
- Depression [9]
- Anxiety
- Bipolar disorder
- Schizophrenia
- Borderline personality disorder
- Narcissism
- Seasonal Affective Disorder and other mood disorders
Light therapy is not new in the world of depression treatment; however, red light therapy is. Seasonal Affective Disorder has long been treated with light, but traditionally, white or blue light has been used. Unlike red light which is safe for the skin and eyes, artificial blue and white light can produce harmful side effects. Red light therapy is growing in popularity as a treatment for depression and disorders like SAD, with its efficacy being progressively proven by science.
One eight-week trial concluded that “NIR light therapy demonstrated antidepressant properties with a medium to large effect size in patients with major depressive disorder.” [10]
Another study on mice induced depressed states by reducing mobility and restricting space. Red light therapy consistently reduced depression-like behaviors in the treatment group of mice. The placebo group continued to exhibit depressed behavior. [11]
Circadian Rhythm and Sleep Patterns
Proper sleep patterns factor into your overall mental state. Your “circadian rhythm” [12] is your internal biological clock that dictates the cycle of when your body instinctively wants to sleep and wake. Circadian rhythm repeats approximately every 24 hours with the rotation of the earth, although this is not exact for everyone.
Circadian rhythms are controlled by a part of your brain called the hypothalamus. Your hypothalamus governs several crucial functions including sleep and growth. The portion of your hypothalamus that responds particularly to light and darkness controls your circadian clock.
Red light applied to your brain stimulates your hypothalamus to produce appropriate levels of melatonin, the hormone that induces your body to maintain healthy sleep patterns. [13] This also helps to counteract the effects of the blue light exposure we encounter every day through the use of electronics and other artificial blue and white light sources.
One study demonstrated that red light increased melatonin production and sleep quality in female basketball players as compared to a control group who received a placebo treatment instead of red light therapy. [14]
Degenerative Neurological Diseases
Clinical research concludes that red light therapy shows great promise in treating a range of debilitating neurological disorders [5], including:
- Alzheimer’s Disease — a progressive brain disorder that causes confusion, thinking and memory problems, and frequently the total loss of short-term memory and a profound loss of long-term memory
- Parkinson’s Disease — a chronic and progressive nervous system disorder affecting movement and causing tremors that become more severe over time [15]
- Huntington’s Disease — a progressive, degenerative condition of nerve cells in the brain causing a decline in thinking and reasoning ability, and involuntary movements such as twitching, jerking, and eventual death
- Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease) — a progressive neurological disorder that results in weakened muscles, deformity, and eventually complete paralysis and respiratory failure
- Multiple Sclerosis (MS) — a disease affecting the central nervous system caused by an abnormal development of protein in brain tissues, creating lesions and plaques on the brain
- Age-Related Cognitive Decline and General Dementia — neurocognitive disorders commonly experienced during advancing age [15]
Treatments and cures for these diseases and disorders have been long sought, but with very limited success. Because aging and degenerative conditions are associated with reduced mitochondrial quality and activity, the cellular energy generated by red light therapy may prove to be a revolutionary breakthrough in treating such neurological disorders and diseases.
One study in which Alzheimer’s patients received red NIR light therapy revealed immediate improvement of cognitive ability, reduced anxiety, a more level emotional state, and less confusion and episodes of wandering. [16]
Traumatic Brain Injury
A traumatic brain injury (TBI) is caused by a forceful blow to the head from an external force, jolting your brain inside your skull. Penetration of the skull by a foreign object (like a bullet) also causes TBI.
A mild TBI is commonly referred to as a concussion. Athletes who participate in high-risk contact sports like football frequently suffer concussions. A mild TBI can affect your brain cells temporarily and repeated instances of mild TBI compound this effect.
A more severe TBI can cause torn brain tissue, damaged brain cells, brain bleeding, and other physical brain damage. In extremely serious instances, death can occur.
The ability of red light to jumpstart your body’s innate healing abilities is the key to its success in treating TBI.
Dr. Michael Hamblin concludes in an abstract that “Many studies in small animal models of acute TBI have found positive effects on neurological function, learning and memory, and reduced inflammation and cell death in the brain. [17]
Studies prove that NIR light not only alleviates the symptoms of TBI but also inhibits neurodegeneration. [12] [9]
In addition to helping heal a TBI, red light therapy can also restore cognitive ability after such an injury. [5] [18] A study involving victims of various accidents (automobile, motorcycle, sports-related, and explosive-related) revealed “significant improvements in executive function and verbal memory” and “fewer post-traumatic stress disorder (PTSD) symptoms reported” after red light therapy. [6]
Another study revealed cognitive improvements in patients experiencing chronic mild TBI. Executive brain function, verbal skills, learning ability, and sleep patterns were all improved, and PTSD symptoms were relieved when they were a factor. [19]
Strokes
There are three basic types of strokes (or “brain attacks”):
- Ischemic Stroke — a “regular” stroke; the interruption or blockage of blood and oxygen flow to your brain causing brain cells to begin dying within minutes [5] [17]
- Hemorrhagic Stroke — a stroke caused by a bleeding artery inside your brain
- Transient Ischemic Attacks (TIA) — a series of “mini-strokes”, sometimes perceptible but sometimes not, with symptoms usually resolving within 24 hours [5]
Symptoms of all types of strokes include bodily weakness, confusion, trouble speaking, and sometimes the inability to move or control different body parts associated with the area of your brain in which the stroke took place.
A 2016 study treated stroke patients who were experiencing pain, weakness, muscle rigidity, and spasticity with red light. Patients exhibited an improvement as to the length of time before muscle fatigue set in and reported experiencing less pain. [20]
Another study performed on mice concludes that: “Non-invasive intervention of LLLT in ischemic brain injury may provide a significant functional benefit with an underlying mechanism possibly being suppression of neuroinflammation and reduction of BBB (blood-brain barrier) disruption.” [21]
Encephalopathy
Encephalopathy is a general term referring to damage to your brain or a disease that affects your brain. A change to your brain has occurred, altering your mental state and causing you to feel confused and act differently than you normally would.
Examples of encephalopathy include:
- Encephalitis — brain swelling and inflammation usually caused by infection
- Encephalomalacia — localized softening of brain tissue due to bleeding or inflammation
- Cerebral Edema — brain swelling causing increased pressure within your skull; can be the result of injury, infection, or an accumulation of fluid in the brain
The anti-inflammatory properties of red light and the activation of stem cells promote healing and recovery from the various conditions of encephalopathy. [22]
In conclusion, red light therapy offers a safe, non-invasive, innovative new approach to unlocking and engaging your ultimate brain capacity.
It is clear that red light therapy is also on the road to becoming a prevalent and powerful means of treating brain injuries, disorders, and psychological conditions. One significant clinical study [5] concluded: “The brain suffers from many different disorders that can be classified into three broad groupings: traumatic events (stroke, traumatic brain injury, and global ischemia), degenerative diseases (dementia, Alzheimer’s, and Parkinson’s), and psychiatric disorders (depression, anxiety, post-traumatic stress disorder). There is some evidence that all these seemingly diverse conditions can be beneficially affected by applying light to the head.”
Red light therapy produces no harmful side effects; however, as always, it is wise to consult with your doctor or another health professional before beginning any new form of treatment.
Resources
[1] Effect of Low-Level Laser Stimulation on EEG (opens in a new tab)
[2] Transcranial infrared laser stimulation produces beneficial cognitive and emotional effects in humans – PubMed (nih.gov) (opens in a new tab)
[3] Photobiomodulation and the brain: a new paradigm – PubMed (nih.gov) (opens in a new tab)
[4] Acute Effects of Near Infrared Light Therapy on Brain State in Healthy Subjects as Quantified by qEEG Measures – PubMed (nih.gov) (opens in a new tab)
[5] Shining light on the head: Photobiomodulation for brain disorders (nih.gov) (opens in a new tab)
[6] Transcranial, Red/Near-Infrared Light-Emitting Diode Therapy to Improve Cognition in Chronic Traumatic Brain Injury – PubMed (nih.gov) (opens in a new tab)
[7] Psychological benefits 2 and 4 weeks after a single treatment with near-infrared light to the forehead: a pilot study of 10 patients with major depression and anxiety – PubMed (nih.gov) (opens in a new tab)
[8] Improvements in Gulf War Illness Symptoms After Near-Infrared Transcranial and Intranasal Photobiomodulation: Two Case Reports – PubMed (nih.gov) (opens in a new tab)
[9] Multi-Watt Near-Infrared Phototherapy for the Treatment of Comorbid Depression: An Open-Label Single-Arm Study – PubMed (nih.gov) (opens in a new tab)
[10] Transcranial Photobiomodulation for the Treatment of Major Depressive Disorder. The ELATED-2 Pilot Trial – PubMed (nih.gov) (opens in a new tab)
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[11] Low-Level Laser Irradiation Improves Depression-Like Behaviors in Mice – PubMed (nih.gov) (opens in a new tab)
[12] What is Circadian Rhythm? | Sleep Foundation (opens in a new tab)
[13] Effects of red light on sleep inertia – PubMed (nih.gov) (opens in a new tab)
[14] Red Light and the Sleep Quality and Endurance Performance of Chinese Female Basketball Players (opens in a new tab)
[15] Brain Photobiomodulation Therapy: a Narrative Review – PubMed (nih.gov)
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[16] Photobiomodulation for Alzheimer’s Disease: Has the Light Dawned? (nih.gov) (opens in a new tab)
[17] Photobiomodulation for traumatic brain injury and stroke – PubMed (nih.gov) (opens in a new tab)
[18] Improved cognitive function after transcranial, light-emitting diode treatments in chronic, traumatic brain injury: two case reports – PubMed (nih.gov) (opens in a new tab)
[19] Significant improvements in cognitive performance post-transcranial, red/near-infrared light-emitting diode treatments in chronic, mild traumatic brain injury: open-protocol study – PubMed (nih.gov) (opens in a new tab)
[20] Effects of low-level laser therapy (LLLT 808 nm) on lower limb spastic muscle activity in chronic stroke patients – PubMed (nih.gov) (opens in a new tab)