Phototherapy uses different colours of light associated with specific wavelengths (blue 450 nm, red 604 nm, infrared 850 nm) to exert a therapeutic influence on biological processes. This involves low-intensity light that does not generate heat and does not damage the tissue. The light beams can be coherent (as with lasers) or non-coherent (as with LEDs).
Key benefits
Numerous randomised clinical trials confirm that photobiostimulation can relieve pain and reduce inflammation.
There is convincing evidence that phototherapeutic treatments are effective for various indications, such as:Limitations
- muscle pain and muscle fatigue
- trauma and functional disorders
- oral mucositis
- neuropathic pain
- depression and head injuries
- lymphoedema and wound healing
- even in fertility support
1) One of the major problems in photomedicine is the limited penetration depth of photons in the human body. Depending on the wavelength and the type of tissue, the penetration depth of photons in soft tissue ranges from 1 to 2 mm for blue light, from 1 to 2 cm for red light, and from 3 to 4 cm for infrared light.
2) A second major problem concerns the optical properties of the light source.
Is a coherent light source (laser) required for the optical biological stimulation of endogenous chromophores, or can the same effects be achieved with non-coherent light sources (LEDs)?
Coherence is a property common to all lasers. The emitted waves are coherent in terms of time and position.
The absorption of photons by biological molecules is, in principle, always a non-coherent process. As long as the size of the molecular target compartment is smaller than the wavelength of the emitted radiation (400–900 nm), the coherent properties of lasers do not manifest themselves. A coherent light source and a non-coherent light source with the same wavelength and intensity cause the same photobiological stimulation. Furthermore, from the perspective of molecular excitation, it is advantageous that the spectral bandwidth of non-coherent light-emitting diodes better matches the spectral bandwidth of chromophores, which typically lies between 30 and 50 nm.
The best-studied endogenous chromophore is cytochrome C oxidase (CCO). The absorption spectrum of CCO exhibits maxima at 660 nm and 850 nm.
For optimal absorption and thus optimal electronic excitation, light sources are required that are adapted to the absorption maxima of CCO. If this condition is met, the energy of the absorbed photons is used exclusively for the electronic excitation of the molecule (specific absorption), without absorption heat being produced in the tissue (non-specific absorption).
In summary, we can conclude that
- Biological stimulation by CCO offers the possibility of normalising dysfunctional mitochondrial metabolism.
- Biological light stimulation of CCO can be carried out using non-coherent light-emitting diodes (LEDs), whose spectrum is adapted to an absorption band of the target molecule and which emit light intensities higher than the critical excitation threshold.
FAQ:
CCO:
The enzyme cytochrome c oxidase, cytochrome oxidase, cytochrome A3 or complex IV of the oxidative phosphorylation (respiratory chain) oxidises four molecules of cytochrome c and reduces one molecule of oxygen, thereby forming two molecules of water. This is the final enzyme in the electron transport chain in the inner membrane of mitochondria.
Laser
A laser is a light source capable of producing a narrow, coherent beam of light. Laser light always produces a beam that converges or diverges very little, if at all.
The word ‘laser’ is an acronym for ‘Light Amplification by Stimulated Emission of Radiation’, in English: light amplification by stimulated emission of radiation.
LED
An LED (from the English light-emitting diode) is an electronic semiconductor component designed as a diode that emits light when current flows through it in the forward direction. This can be visible light in various colours, but also infrared or ultraviolet radiation.
CHROMOPHORE
The chromophore, literally: colour carrier, is the part of the molecule responsible for the absorption of light in the visible and ultraviolet regions of the electromagnetic spectrum.
ATP – Adenosine triphosphate
an increase in ATP, the primary energy source for most cellular functions, enhances the cell’s ability to fight infections and accelerates the healing process.
ROS – reactive oxygen species;
modulation of ROS activates transcription factors that have a positive effect on cell repair and healing.
NO – Nitric oxide;
the release of NO, a powerful vasodilator, increases blood circulation, reduces inflammation and improves the transport of oxygen and immune cells through the tissue.
Mitochondria:
Your energy levels do not depend on your mood, but on your cells. Every cell in your body contains on average between 500 and 2,000 mitochondria. An adult’s body consists of approximately 30 trillion cells, or roughly 30,000 trillion mitochondria. They originated from parasites and invaded the cells of our ‘ancestral organisms’ around a billion years ago. In exchange for the fuel they provide, the cells harbour the mitochondria.
Mitochondria are veritable molecular power stations. They convert food into nutrients 24 hours a day, 7 days a week. Your body can produce 3 types of fuel from food. The body’s cells derive their energy primarily from the burning of glucose. Mitochondria burn glucose, producing ATP. ATP is the fuel for your cells and is used throughout your body.
- Proteins are broken down into amino acids,
- fats are broken down into fatty acids
- Sugars are broken down into smaller units and produce glucose.
Comparison between needle acupuncture and Acu-LED therapy
Origins
Acupuncture: an ancient tradition, still relevant today
Acu-LED therapy: 2023 Kay Aubrey-Chimene (United States), Verbanck Hervé (Belgium)
Mechanism of action
Needle acupuncture:
- increase in histamine following the destruction of approximately 500,000 cells
- reduction in the membrane potential of peripheral nerves, the nociceptors
- formation of action potential (AP) cascades at the acupuncture point
Acu-LED therapy:
Increases the production of mitochondrial ATP
Reactive oxygen species (EROx) are formed
NO is released
Increase in RNA/DNA synthesis
These four effects trigger a cascade of stimulating effects on the mitochondria (cells) via the central nervous system to the brain.
Local action
Acupuncture with needles:
Acts on a single point, suitable for ting points and the head
Acu-LED therapy:
Acts on the area around a point and stimulates the underlying area, as an acupuncture point is the tip of a cone lying deeper beneath the skin; not suitable for ting points; do not use on the scalp.
Effect over time:
Acupuncture with needles:
maximum stimulation upon insertion of the needle, peaks and troughs during manipulation of the needle
Acu-LED therapy:
Stimulation reaches its maximum after 1 minute and the intensity remains constant.
Duration of treatment:
Acupuncture with needles:
20 to 30 minutes, after which the effect wears off
Acu-LED therapy:
10–15 minutes; any longer cancels the effect
Effect on cells
Acupuncture with needles : destruction of approximately 50,000 cells per needle
Acu-LED therapy:
Stimulation of the CCO in the mitochondria of a larger area of cells belonging to the acupuncture point.
Two simultaneous wavelengths possible in a single zone (650 nm and 850 nm)
Pain-relieving effect:
Acupuncture: pain-relieving effect enhanced by electro-acupuncture
Acu-LED therapy: pain-relieving effect thanks to the pulsed frequency
Benefits:
Acupuncture with needles:
self-healing capacity, pain relief
Acu-LED therapy:
self-healing capacity, pain-relieving, cell regeneration, wound healing, anti-inflammatory
Risks:
Acupuncture with needles:
With frequent use of the same points, effectiveness may decrease due to the continuous destruction of cells by scar tissue, the risk of pneumothorax and bleeding.
Acu-LED therapy:
no risk, home treatments possible
Conclusion:
Both are equivalent and compatible, but the Acu-LED is an indispensable addition for applying acupuncture safely and accurately, in terms of safety, cost and the ability to carry out treatments at home.
Bibliography:
Effect of coherent red light (laser) and non-coherent red light (LED) on the rate of DNA synthesis in HeLa cells T. Karu ‘10 lectures on the fundamental sciences of laser phototherapy’ Prima Books AB, Sweden, Grängesberg, 2007, pp. 84–85
D. Schikora, Faculty of Science, Biophysics Group Non-coherent light sources, such as LEDs, may have even more beneficial effects thanks to their better spectral adaptation to the broad absorption bands of biological molecules!