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Red light therapy or photobiomodulation

Article aimed at all people who want to understand or expand their knowledge about how light therapy positively affects the body. With a specific description of red therapy or photobiomodulation

Whole body red light therapy or photobiomodulation

Cell regeneration therapy


A little history of light therapy

Phototherapy, in the strict sense, is the therapeutic use of light. This physical agent, light, has accompanied man since his presence on earth began; it is responsible for life as we currently know it. Together with other physical and chemical agents such as water, oxygen and terrestrial magnetism, they make life possible.

The sun is a source of thermal energy that provides cyclical lighting conditions to which numerous plants and animals have adapted, and provides essential radiation to trigger important chemical reactions.

Since ancient times, man has learned to use the therapeutic resources of solar radiation.

In a broad sense, phototherapy includes treatment with visible light, infrared and ultraviolet radiation, both in its natural form of production, considering the sun as a therapeutic agent (heliotherapy) and in those artificial forms of production of infrared radiation or ultraviolet.


Solar emission

The sun is the main natural source of light production and other radiation of interest in phototherapy. The large number of elements and energy transitions that occur in it make its radiation very varied.

The solar radiation that reaches the Earth's surface is composed of:

59% infrared (IR) radiation

40% visible light

1% ultraviolet (UV) radiation

This gives diverse effects to sunlight, photothermal, photoluminous and photochemical effects.

Today, practically all components of the solar radiation spectrum can be achieved by artificial means.

Infrared radiation (IR) includes radiation whose wavelengths are between 760 and 15,000 nm. For practical purposes, IR is usually divided into near IR (60-1,500 nm) and long IR (1,500 -15,000 nm).

UV radiation occupies the part of the electromagnetic spectrum between visible light and lower energy X-rays. The limit with visible light is around 400 nm, which is the limit of visual perception of the color violet. Since the limit is physiological, some authors place it between 400 and 390 nm.

The sun is the main natural source of this radiation; It emits in a wide range of UV frequencies.

The biological effects are highly variable and depend on the wavelength; For this reason, the ultraviolet spectrum is subdivided into three regions: UV-A: 400-320 nm UV-B: 320-290 nm UV-C: 290-200 nm

Visible light constitutes the range of the spectrum perceptible by the human retina. Under normal conditions, it includes wavelengths from 780 to 400 nm, located between IR and UV radiation. "White" light is actually a mixture of different colors (those in the visible spectrum), each with different wavelengths. Normally, we talk about the seven spectral colors: red, orange, yellow, green, blue, indigo and violet. These are fairly easily distinguished in the decomposition of white light, both artificially, using a prism, and naturally, the best-known example of which is the rainbow. Each of these light spectrums have different therapeutic properties (Chromotherapy).

Physical scheme of light

How light therapy works

Photobiomodulation Therapy (TFBM) is the application of light that covers all wavelengths (Infrared – visible light – ultraviolet) especially those of red and near infrared wavelengths for therapeutic purposes acting on the activation of the biological systems of certain light receptor proteins, called mitochondria.

Low-level laser light photobiomodulation (LLLT) works on the principle of inducing a biological response through energy transfer, in the sense that the photonic energy delivered to the tissue by the laser modulates the biological processes within of the fabric.

Light energy is transmitted through space as waves containing small "energy packets" called photons.

Each photon contains a defined amount of energy depending on its wavelength (color). Blue photons have more energy than green photons and green photons have more energy than red or NIR photons.

The photons that are absorbed interact with an organic molecule or "chromophore" located within the tissue.

The absorption of photons by chromophobic molecules leads to electronically excited states, and consequently can lead to an acceleration of electron transfer reactions.

More electron transport necessarily leads to greater production of ATP energy by the mitochondrial respiratory chain.

The light-induced increase in ATP synthesis and increased proton gradient leads to an increase in the activity of the Na+/H+ pumps and Ca2+/Na+antiporters, and of all carriers. driven by ATP, such as Na + / K + ATPase and Ca2+

Therefore mitochondria are the key to photobiomodulation.

And within these mitochondria the “Cytochrome C oxidase” proteins can absorb red light, converting photon energy into biological energy ATP.

Cytochrome C oxidase behaves as a photon acceptor"chromophore" that catalyzes activity at the cellular level when exposed to near-infrared red light.

The absorption of colors is different within the mitochondrial respiratory chain:

Complex I (NADH dehydrogenase) absorbs blue and ultraviolet light.

Complex III (cytochrome c reductase) absorbs green and yellow light.

Complex IV (cytochrome c oxidase) absorbs red and infrared light.

With Photobiomodulation therapy, mitochondria change into "giant mitochondria" with the activation of several metabolic pathways and the increase in ATP production due to the activation of the respiratory chain directly on Cytochrome C oxidase, which acts by stimulating the intracellular NF-kB pathway, which are proteins that help control many functions in the cell, such as growth and survival to cellular hypoxia stress and immune and inflammatory responses. Furthermore, it induces intracellular reactive oxygen species (ROS Free Radicals), which may also play a role in the NF-kB signaling pathway, and reduce cell apoptosis and a normalization of the mitochondrial membrane potential with the normalization of tissue metabolism due to the significant increase in antioxidant enzymes SOD and GTx.

Effect of red light therapy on cells

Use of wavelengths in photobiomodulation

Red light therapy or photobiomodulation is the application of red and near-infrared wavelengths to diseased, injured or dying cells.

The target of light photons are free radicals. These bind inappropriately to the oxygen receptor in the cell's energy reproduction cycle, triggering a chain of stress, generating inflammation, and if left unchecked, eventually cause cellular damage and are considered the underlying cause of all diseases. .

This process is known as oxidative stress.

The red light emitted increases cellular respiration, inflammation decreases, circulation increases, neutralizing oxidative stress.

The cells are then able to repair themselves as they are naturally programmed, because the hindrance of inflammation and energy reduction have been removed and the basic components of circulation and energy production have been restored.

The absorption of the mN0 molecule by the lining of blood vessels causes vasodilation, thus increasing circulation.

Photobiomodulation red light therapy

Red and near infrared light emitted by LEDs is used

Wavelengths used in photobiomodulation

There are numerous clinical studies that demonstrate the positive effect of red light photobiomodulation therapy. Below we copy a couple of them published in the National Library of Medicine (English)

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