Does Red Light Therapy Help Alzheimer’s Disease?

Red Light Therapy for Alzheimer's

Hundreds of peer-reviewed studies have shown red light’s benefits on brain health. In this article, we’ll discuss the therapeutic benefits of red light therapy for Alzheimer’s disease, and how red light may well become a key factor in slowing and potentially stopping the progression of this debilitating and devastating condition.

Alzheimer’s treatments typically focus on helping patients maintain mental function, while managing behavioral changes and slowing the progression of the disease. It is very common for Alzheimer’s patients to be treated with prescription drugs, which appear to work best in the early or middle stages of the disease. Currently, no medication stops the progression of Alzheimer’s disease, and it is considered incurable.

Red light therapy, which is also known as photobiomodulation (PBM) or low-level light therapy (LLLT),  is a different type of approach for treating Alzheimer’s. It works at the cellular level, targeting potential causes or contributing factors, which may lead to a reduction of symptoms.

Light Therapy for Alzheimer’s 

Before we explore how red light may benefit people with Alzheimer’s disease, we’ll review bright light therapy, which has been used as an Alzheimer’s treatment. What bright light therapy shares in common with red light is that it is natural, safe, and non-invasive.

Bright light therapy has been used for many years to treat seasonal affective disorder, as well as non-seasonal depression, and to regulate the circadian rhythm (natural sleep-wake cycle). A patient being treated with bright light therapy sits in front of a light therapy box with eyes open, so that light can enter through the retinas.

Alzheimer’s disease is often associated with prolonged/excessive daytime napping and nighttime restlessness. According to a 2013 review by researchers from the Rensselaer Polytechnic Institute, bright light therapy is beneficial for Alzheimer’s sufferers. It can be used to reset their circadian rhythm, thereby promoting restful sleep at night and restoring normal sleep. This can help minimize wandering, agitation, disruptive behavior, and sleep disturbances. 

There are, however, some challenges associated with bright light therapy as a treatment for Alzheimer’s disease. Adhering to the treatment requirements could prove difficult for Alzheimer’s patients because ...

  • The patient must take bright light therapy with the eyes open, but the light must enter the eyes indirectly, which means not looking directly at the light box;
  • The therapy is fairly lengthy: 45-minute to two-hour exposures have shown positive results, but the duration could pose a challenge;
  • The therapy must be administered at the correct time of day to move a person’s internal clock either forward or backward to bring it back into sync with normal daylight. 

Red light therapy, which we’ll cover in the next section, may be more effective for people with Alzheimer’s disease because ...

  • Light is administered via the forehead, so the patient can be relaxing or even sleeping;
  • Shorter treatment times may help reduce agitation/belligerence at having to sit still for so long.

In addition, red light has some unique qualities that make it an excellent therapy for neurodegenerative disorders.

Red and Near-Infrared Light Therapy for Alzheimer’s

Old Man with red light on his face

Red light and near-infrared (NIR) light are some of the most exciting treatments for the brain. “Many investigators believe that PBM for brain disorders will become one of the most important medical applications of light therapy in the coming years and decades,” says Michael R. Hamblin, who is an associate professor of dermatology at Harvard Medical School and a world-renowned expert on red light therapy.

Red light therapy is non-invasive, natural, and safe. According to an article in the 2016 edition of “Frontiers of Neuroscience,” red and near-infrared light therapy “Has neuroprotective effects, slowing the underlying death of neurons.” And the neuroprotective effects of red light are just the start. Below we’ll dive into the benefits of red light for a variety of Alzheimer’s symptoms. But first, let’s do a quick overview of what red light therapy is and how it works. 

What Is Red Light Therapy?

“Red light therapy” is often used as an umbrella term that encompasses red and NIR wavelengths of light. Through years of research and thousands of studies, scientists now know that the greatest therapeutic benefits are from red light, which ranges from 630 nanometers (nm) to 660nm; and NIR light, which ranges from 810nm to 850nm. This range of wavelengths is what’s known as the therapeutic window. 


Red light therapy, especially using NIR wavelengths, is poised to become a leading therapy for overall brain health. Research has clearly shown that PBM has beneficial effects on the central nervous system as a whole. It has been used to treat Parkinson’s disease, multiple sclerosis, traumatic brain injury, and stroke, as well as neurodegenerative disorders.

How Does Red Light Therapy Work?

The short answer is that red light heals the body at the cellular level, rather than temporarily masking symptoms. The longer answer is complex, but fascinating.

Powerful light-emitting diode (LED) bulbs deliver red/NIR light onto the forehead, where the light photons pass through the skull into brain tissue. While red LED light devices have been used in clinical trials for various brain conditions, the greatest results will come from near-infrared light, which delivers wavelengths that can effectively, and safely, absorb into the brain.

What does red light do once it’s absorbed into the brain?

mitochondria receiving energy from red light

Supercharging Cells

The most profound effect of red light therapy, which is at the heart of the chain of events that stimulates healing, is improved cell functioning. When red light is absorbed by the body, light photons interact with mitochondria inside cells, which are colloquially referred to as cellular “energy factories.” This stimulates the mitochondria to produce more cellular fuel, which energizes cells. 

An energized cell is a thriving cell. In fact, many studies, including a joint effort between Case Western Reserve University and the University of Texas, confirm that mitochondrial dysfunction (low-energy cells) is one of the primary causes of Alzheimer’s disease. In the published study, the authors state that when mitochondria are structurally and functionally damaged due to oxidative stress, they are early stage markers of the disease.

Reduced Inflammation and Oxidative Stress

Brain inflammation interferes with normal central nervous system (CNS) functioning and is a known cause/contributing factor in the development of Alzheimer’s. According to Dr. Hamblin, photobiomodulation reduces inflammation of CNS tissue (known as neuroinflammation) by modulating levels of both pro- and anti-inflammatory cytokines. It also reduces inflammation by promoting blood flow, which helps remove waste products.

In a 2017 publication titled “Oxidative Stress and the Central Nervous System,” University of Houston pharmacologist Dr. Samina Salim explains that oxidative stress is caused by imbalance in reactive oxygen species (ROS), which are a byproduct of cellular metabolism. 

Normally, the rate of ROS production and clearance is balanced by antioxidants. In people with Alzheimer’s, ROS production is too high, or there’s not enough antioxidants to neutralize them, which causes oxidative stress. Dr. Salim writes: “Oxidative stress–induced damage to the brain has a strong potential to negatively impact normal CNS functions.”

Oxidative stress leads to progressive mitochondrial dysfunction and a downward spiral of more oxidative stress, worsening cell functioning, even more oxidative stress… and eventually, permanent damage of the neurons.

In a 2009 study on cultured neural cells, researchers from Italy found 670nm photobiomodulation to be neuroprotective against oxidative stress. They also found that PBM stimulated the maturation of neurons.

Increased Circulation

Vascular dysfunction and micro-hemorrhages, which are associated with Alzheimer’s, can diminish blood flow in the brain. Micro-hemorrhages may indicate breakdowns of the blood-brain barrier, which is considered to be an early marker of cognitive dysfunction. 

According to a 2017 study by researchers from Pennsylvania, infections that stimulate innate immune responses likely worsen the problem. The study authors write: “Normally, brain immune cells called microglia clear beta amyloid proteins from the brain. But when these cells get fired up in response to infection, they stop, causing the proteins to build up even faster.”

Another 2017 study shows that red light stimulates the formation of capillaries in the brain and promotes production of nitrous oxide (NO), a vasodilator. This increases blood flow to various parts of the brain, including those that have been damaged by Alzheimer’s. Good blood flow throughout the brain gives the microglia (a type of brain cell) a chance to clear amyloid plaques from the brain. Red light also stimulates growth of endothelial cells (part of what makes up capillaries), to bring nutrients and oxygen to brain cells.

Neuroprotection

As previously noted, red and NIR wavelengths can reduce inflammation and oxidative stress. Protecting neurons against damage from inflammatory oxidative stress helps ensure their longevity; this has potential to slow the progression of neurodegenerative disorders like Alzheimer’s.

A 2015 study by researchers from Australia found that one month of near infrared light therapy protected mouse brains from oxidative stress and mitigated the degeneration of many (if not all) parts of the brains of treated mice. 

Tau proteins and beta-amyloid proteins are the two proteins that are well known to contribute to Alzheimer’s when they malfunction. In a 2018 study published in Molecular Neurobiology, researchers from the University of Texas exposed mice with dementia to four weeks of NIR light. This resulted in significantly reduced tau and beta-amyloid levels and improved the animals’ deteriorating memory functions.  

These are a few of the effects that PBM has on overall brain health. Here’s how red light may benefit people with Alzheimer’s symptoms while addressing the underlying causes.

Red Light for Alzheimer’s Symptoms

The most common Alzheimer’s symptoms can be broken down into memory-related decline, cognitive decline, social/behavioral decline, and to a lesser extent, physical decline.

Memory-Related Decline

Forgetting information that was recently learned is one of the early signs of Alzheimer’s disease. The inability to form new memories gets progressively worse; but the disease also attacks long-term memory, including forgetting important dates such as birthdays or anniversaries, or not recognizing family members. Someone with Alzheimer’s may have trouble performing familiar tasks like driving to the grocery store or remembering the rules of a game. Another common symptom is misplacing objects in unfamiliar places, like putting a cell phone in the freezer or wedding rings in the microwave.

Red light therapy has shown great promise in helping with memory issues. In a 2019 study, researchers from South Korea found that red light (660nm) effectively reduced oxidative stress in the hippocampus, the area of the brain responsible for emotional self-regulation, learning, memory, and motivation.

Sleep is crucial to the formation of memories. According to Dr. Hamblin, the body naturally produces melatonin from red light, and, he explains, “Medical research from many clinical trials has shown improved sleep disorders from red light therapy.”

Effect on brain by Red Light Therapy

Cognitive Decline

Tasks such as following directions, working with numbers, following a recipe, or keeping track of bills can be challenging for Alzheimer’s patients. They often have difficulty concentrating and take much longer to perform familiar tasks than before they developed the disease. Dates and places are often mixed up, they have trouble with judging distance and seeing color or contrast, and may feel off-balance. They may experience changes in decision-making and judgment, such as ignoring self-care.

How red light can help: PBM activates the prefrontal cortex, an area of the brain responsible for executive functions including focused attention, reaction times, goal-setting, impulse control, predicting, planning and anticipating.  

Clinical trials have shown impressive improvements in cognitive scores, better sleep, decreased anxiety, fewer emotional outbursts, and less wandering immediately after treatment. 

A 2017 study by medical researchers from Iran showed potential for both red and near infrared light to reduce age-related mitochondrial dysfunction, apoptosis (neural cell death), and cognitive impairment. After PBM treatment, researchers assessed the brains of mice and found significant improvements in mitochondrial function, including active mitochondria and cellular fuel known as adenosine triphosphate (ATP).

A 2017 study by researchers from the University of Texas focused on older adults at risk of developing dementia. After treatment with NIR light therapy at 1064nm, all participants showed improvement in all cognitive measures.

social connection

Social/Behavioral Decline

Alzheimer’s patients often have trouble following the plot of a movie or a conversation, repeatedly ask the same questions, struggle with vocabulary, and may call familiar objects by the wrong name. They may become more agitated and belligerent with their loved ones, withdraw from group activities and hobbies, stop following a favorite sports team, and seem to zone out when in family or social gatherings. Some experience mood and personality changes including confusion, depression, suspicion, and anxiety, especially when they are somewhere unfamiliar. 

How red light can help: A 2013 study by University of Texas researchers found that PBM helps regulate neuronal function, which stimulates emotional self-regulation. The patients who received PBM showed more sustained positive emotional states when compared with the control group. 

An October 2016 article by Dr. Hamblin, which appeared in the biomedical journal BBA Clinical, reviews studies showing that PBM promoted better sleep, fewer emotional outbursts, and reduced anxiety in Alzheimer’s patients.

bodily decline

Physical Decline

Although Alzheimer’s is not typically considered a physically debilitating disorder, some patients may experience loss of balance. Aside from faulty sensory (visual) information processing, feeling off balance may be due to loss of communication between the central and peripheral nervous systems. 

PBM improves nerve regeneration by reversing mitochondrial dysfunction, and by stimulating the production of Schwann cells, which are part of the protective myelin sheath around nerves.

Vision problems are one early indicator of Alzheimer’s. Vision problems can include difficulty discerning contrast/color and loss of the ability to judge distance, both of which can contribute to feeling off balance. 

A 2015 study by researchers from London, UK found that PBM reduced mitochondrial decline in the retinas of mice. Other research has found that treatment with PBM can help regenerate optic nerves, and appears to have a neuroprotective effect on the eyes.

Home Therapy for Alzheimer’s Disease 

Treatment for Alzheimer’s disease should always be supervised by a doctor. You can, however, (with your doctor’s approval) use red light therapy with a loved one who suffers from Alzheimer’s to boost cognitive functioning, memory, moods, and overall brain health. 

At the same time, PBM can help relieve the symptoms of other conditions commonly associated with aging including aching joints, neuropathy, and inflammatory disorders. 

You will get the most significant therapeutic benefits by using a high-output LED therapy device that delivers the optimal red and NIR wavelengths. Learn more about the PlatinumLED BIO and BIOMAX panels—the most powerful panels on the market. Powerful light output matters, because you want the maximum number of light photons to absorb into the brain tissue. Weaker low-output lights can’t measure up, so don’t waste your money on cheap handheld devices.

With the BIOMAX series, you can even mount the panels on a vertical or horizontal stand. By doing so, the patient can sit or lie comfortably in any comfortable position while receiving red light therapy.

Consistency is important, since red light works at the cellular level. Giving the body the boost it needs to reduce inflammation, regenerate neurons, and even restore cognitive functioning will take time..

Don’t Give Up Hope … Try Red Light Therapy 

Most research on Alzheimer’s-specific PBM has been with animals, but the few clinical trials on humans have found significant improvements in cognitive functioning, sleep quality, and moods. 

Red light therapy is a natural and safe therapeutic method for those who suffer from brain disorders. Its cellular-level benefits can have a powerful ripple effect throughout the brain. As more and more studies are confirming, PBM may slow the progression of neurodegenerative disorders like Alzheimer’s disease, as well as Parkinson’s and Multiple Sclerosis.

To learn more about how red light therapy can contribute to overall wellness, visit the PlatinumLED blog.