Red and near-infrared light are a subset of sunlight, which has actual value as a nutrient. Red and near-infrared light therapies can produce those benefits, and it may be beneficial to individuals who lack adequate exposure to sunlight.
Our bodies need sunlight for normal cell function. A lack of exposure to sunlight can result in abnormal cell function. And there are many mechanisms through which this can happen.
Vitamin D production is a well known benefit of exposure to sunlight. It helps regulate more than 2,000 genes related to musculoskeletal health, immune health, and more.
Red light therapy
The current red and near-infrared light therapy has its foundation in Heliotherapy, which is sun-based therapy. Heliotherapy has long been used to treat many diseases such as tuberculosis.
Over the past several decades, over 5,000 studies have been published about red and near-infrared light therapy, which is also called photobiomodulation. The studies have investigated the efficacy of this therapy to treat everything from accelerated injury recover and hair growth to reducing cellulite and wrinkles. Other benefits can include improvement in strength levels, better muscle protein synthesis, greater fat loss, and increased insulin sensitivity when using it together with exercise as opposed to exercise alone.
Some research shows that red and near-infrared light therapy can help people with Hashimoto’s hypothyroidism by decreasing thyroid antibodies. Other studies show help for diabetic ulcers, arthritis pain, tissue and bone healing, and joint health.
Researchers are also investigating red and near-infrared light therapy to help Parkinson’s and Alzheimer’s patients, although they face challenges in delivering the therapy, which must penetrate the skull.
Moderation is key
A common misunderstanding is that more is better with a beneficial therapy. This is not the case with red and near-infrared therapy. The right amount can produce positive effects, but too much may result in negative effects. Moderation is the key.
Even so, the risk of getting too much red and near-infrared dosage is small. For instance, when compared with exercise, you have a higher risk of tissue damage from overdoing it than you would have from overdoing red and near-infrared light therapy.
Still, the potential exists. This may be because light therapy is a type of hormetic stress, much like fasting and exercise. It works by increasing reactive oxygen species or free radicals. Individuals with very poor mitochondrial health will have a low resilience threshold. Their ability to tolerate the burst of reactive oxygen species will be low. They are creating damage, and their bodies can’t effectively recover from it.
Mechanisms of action
Red and near-infrared light therapy works through several mechanisms of action. The most well-known mechanism is cytochrome c oxidase, which is a photoreceptor on your mitochondria that captures the photons of red and near-infrared light. The most effective wavelengths that activate this system are in the 600 to 700 nanometer and the 800 to 1,000 nanometer ranges. In response to those light photons, your mitochondria will produce energy more efficiently. Hence, your other cells will work better when the mitochondria produce more energy. This is one general principle of how this therapy helps such a diverse range is issues.
Another mechanism is associated with the benefits of hormesis and the transient spike in reactive oxygen species. That burst of reactive oxygen species creates a cascade of signaling effects that stimulate the NRF2 pathway and heat shock proteins.
The intracellular antioxidant response system is strengthened this way. The mitochondria grow stronger and larger. It also stimulates mitochondrial biogenesis, the creation of new mitochondria. This increases your resistance to a wide array of environmental stressors.
When given correct doses, red and near-infrared light therapy will temporarily stress the system and stimulate adaptive mechanisms that make the entire system more resilient.
Light therapy modulates gene expression
Another key mechanism of action involves retrograde signaling and the modulation of gene expression. The mitochondria have a key role in this as well. Mitochondria sense environmental elements including toxins, pathogens, and inflammatory cells. They sense the light signals and reactive oxygen species from hormetic stress. They relay the signals back to the mitochondria in a way that modulates gene expression.
There is a certain set of genes that respond to red and near-infrared light therapy. These are genes involved in cellular growth, cell regeneration, and cell repair.
In the brain, it activates brain derived neurotrophic factor (BDNF). In the skin, it increases expression of fibroblasts that synthesize collagen, and in muscles, it locally increases expression of IGF1 and factors involved in muscle protein synthesis.
In addition, exposure to UVA, red light and near-infrared light increases the release of nitric oxide (NO) which has many metabolic benefits in optimal concentrations. Many of the benefits of sun exposure cannot be explained solely through the production of vitamin D, and the influence of NO may solve that part of the puzzle.
Other research suggests that red and near-infrared light interact with chlorophyll metabolites in a way that helps recycle ubiquinol from ubiquinone (the reduced version of CoQ10).
So, those specific wavelengths of light may help recycle reduced CoQ10, which also enhances energy production. Scientists are studying the synergy between diet and red and near-infrared light therapy. Consuming more chlorophyll-rich compounds may improve the effect.
Final thoughts
Many people are not getting enough exposure to sunlight, especially this last year due to COVID-19 isolation. Now more than ever, it’s time to get out and enjoy the sunlight and beauty of nature. You will be helping your own body strengthen and heal.