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Light therapy is definitely experiencing a surge in popularity. You can now buy illuminated devices targeting issues like complexion problems and aging signs as well as muscle pain and gum disease, recently introduced is an oral care tool outfitted with tiny red LEDs, described by its makers as “a breakthrough for domestic dental hygiene.” Internationally, the industry reached $1 billion in 2024 and is forecast to expand to $1.8 billion by 2035. There are even infrared saunas available, which use infrared light to warm the body directly, your body is warmed directly by infrared light. Based on supporter testimonials, it’s like bathing in one of those LED-lit beauty masks, boosting skin collagen, relaxing muscles, alleviating inflammatory responses and chronic health conditions while protecting against dementia.

Research and Reservations

“It sounds a bit like witchcraft,” says a Durham University professor, professor in neuroscience at Durham University and a convert to the value of light therapy. Of course, some of light’s effects on our bodies are well established. Sunlight helps us make vitamin D, crucial for strong bones, immune defense, and tissue repair. Natural light synchronizes our biological clocks, too, stimulating neurotransmitter and hormone production during daytime, and winding down bodily functions for sleep as it fades into night. Sunlight-imitating lamps are standard treatment for winter mood disorders to combat seasonal emotional slumps. So there’s no doubt we need light energy to function well.

Different Light Modalities

While Sad lamps tend to use a mixture of light frequencies from the blue end of the spectrum, most other light therapy devices deploy red or infrared light. During advanced medical investigations, such as Chazot’s investigations into the effects of infrared on brain cells, finding the right frequency is key. Light is a form of electromagnetic radiation, which runs the spectrum from the lowest-energy, longest wavelengths (radio waves) to the highest-energy (gamma waves). Phototherapy, or light therapy employs mid-spectrum wavelengths, including invisible ultraviolet radiation, then visible light (all the colours we see in a rainbow) and then infrared (which we can see with night-vision goggles).

Dermatologists have utilized UV therapy for extensive periods for addressing long-term dermatological issues like vitiligo. It works on the immune system within cells, “and reduces inflammatory processes,” explains Dr Bernard Ho. “Considerable data validates phototherapy.” UVA penetrates skin more deeply than UVB, whereas the LEDs we see on consumer light-therapy devices (usually producing colored light emissions) “tend to be a bit more superficial.”

Safety Considerations and Medical Oversight

Potential UVB consequences, such as burning or tanning, are recognized but medical equipment uses controlled narrow-band delivery – indicating limited wavelength spectrum – which minimises the risks. “Treatment is monitored by medical staff, so the dosage is monitored,” says Ho. And crucially, the light sources are adjusted by technical experts, “to ensure that the wavelength that’s being delivered is fit for purpose – different from beauty salons, where it’s a bit unregulated, and we don’t really know what wavelengths are being used.”

Home Devices and Scientific Uncertainty

Red and blue LEDs, he says, “aren’t really used in the medical sense, though they might benefit some issues.” Red light devices, some suggest, improve circulatory function, oxygen uptake and dermal rejuvenation, and activate collagen formation – a primary objective in youth preservation. “Studies are available,” comments the expert. “But it’s not conclusive.” In any case, amid the sea of devices now available, “it’s unclear if device outputs match study parameters. We don’t know the duration, how close the lights should be to the skin, whether or not that will increase the risk versus the benefit. Many uncertainties remain.”

Specific Applications and Professional Perspectives

One of the earliest blue-light products targeted Cutibacterium acnes, a microbe associated with acne. Research support isn’t sufficient for standard medical recommendation – despite the fact that, says Ho, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he says, though when purchasing home devices, “we advise cautious experimentation and safety verification. If it’s not medically certified, oversight remains ambiguous.”

Cutting-Edge Studies and Biological Processes

Meanwhile, in innovative scientific domains, researchers have been testing neural cells, discovering multiple mechanisms for infrared’s cellular benefits. “Pretty much everything I did with the light at that particular wavelength was positive and protective,” he says. It is partly these many and varied positive effects on cellular health that have driven skepticism about light therapy – that results appear unrealistic. However, scientific investigation has altered his perspective.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, but over 20 years ago, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He designed tools for biological testing,” he says. “I remained doubtful. The specific wavelength measured approximately 1070nm, that many assumed was biologically inert.”

Its beneficial characteristic, nevertheless, was its efficient water penetration, meaning it could penetrate the body more deeply.

Cellular Energy and Neurological Benefits

More evidence was emerging at the time that infrared light targeted the mitochondria in cells. Mitochondria are the powerhouses of cells, creating power for cellular operations. “Mitochondria exist throughout the body, particularly in neural cells,” says Chazot, who concentrated on cerebral applications. “Research confirms improved brain blood flow with phototherapy, which is generally advantageous.”

Using 1070nm wavelength, energy organelles generate minimal reactive oxygen compounds. In limited quantities these molecules, says Chazot, “triggers guardian proteins that maintain organelle health, look after your cells and also deal with the unwanted proteins.”

All of these mechanisms appear promising for treating a brain disease: antioxidant, inflammation reduction, and pro-autophagy – autophagy being the process the cell uses to clear unwanted damaging proteins.

Current Research Status and Professional Opinions

Upon examining current studies on light therapy for dementia, he says, about 400 people were taking part in four studies, incorporating his preliminary American studies