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Light therapy is certainly having a moment. Consumers can purchase illuminated devices targeting issues like complexion problems and aging signs as well as aching tissues and gum disease, recently introduced is an oral care tool outfitted with small red light diodes, marketed by the company as “a major advance for domestic dental hygiene.” Internationally, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. You can even go and sit in an infrared sauna, where instead of hot coals (real or electric) heating the air, the thermal energy targets your tissues immediately. As claimed by enthusiasts, the experience resembles using an LED facial mask, boosting skin collagen, easing muscle tension, alleviating inflammatory responses and persistent medical issues while protecting against dementia.

Understanding the Evidence

“It appears somewhat mystical,” says a neuroscience expert, who has researched light therapy for two decades. Certainly, certain impacts of light on human physiology are proven. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Light exposure controls our sleep-wake cycles, as well, activating brain chemicals and hormonal responses in daylight, and signaling the body to slow down for nighttime. Daylight-simulating devices are a common remedy for people with seasonal affective disorder (Sad) to combat seasonal emotional slumps. Undoubtedly, light plays a vital role in human health.

Various Phototherapy Approaches

While Sad lamps tend to use a mixture of light frequencies from the blue end of the spectrum, the majority of phototherapy tools use red or near-infrared wavelengths. During advanced medical investigations, including research on infrared’s impact on neural cells, determining the precise frequency is essential. Photons represent electromagnetic waves, spanning from low-energy radio waves to high-energy gamma radiation. Therapeutic light application utilizes intermediate light frequencies, with ultraviolet representing the higher energy invisible light, then the visible spectrum we perceive as colors and infrared light visible through night vision technology.

Ultraviolet treatment has been employed by skin specialists for decades to treat chronic skin conditions such as eczema, psoriasis and vitiligo. It works on the immune system within cells, “and reduces inflammatory processes,” explains Dr Bernard Ho. “Substantial research supports light therapy.” UVA goes deeper into the skin than UVB, in contrast to LEDs in commercial products (which generally deliver red, infrared or blue light) “typically have shallower penetration.”

Safety Considerations and Medical Oversight

The side-effects of UVB exposure, like erythema or pigmentation, are well known but in medical devices the light is delivered in a “narrow-band” form – indicating limited wavelength spectrum – which minimises the risks. “Therapy is overseen by qualified practitioners, thus exposure is controlled,” explains the dermatologist. Essentially, the lightbulbs are calibrated by medical technicians, “to confirm suitable light frequency output – unlike in tanning salons, where oversight might be limited, and wavelength accuracy isn’t verified.”

Home Devices and Scientific Uncertainty

Colored light diodes, he says, “aren’t typically employed clinically, though they might benefit some issues.” Red wavelength therapy, proponents claim, enhance blood flow, oxygen uptake and dermal rejuvenation, and stimulate collagen production – an important goal for anti-aging. “Research exists,” says Ho. “Although it’s not strong.” In any case, with numerous products on the market, “it’s unclear if device outputs match study parameters. Appropriate exposure periods aren’t established, proper positioning requirements, if benefits outweigh potential risks. 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 frequently employed in beauty centers.” Individuals include it in their skincare practices, he says, but if they’re buying a device for home use, “we recommend careful testing and security confirmation. If it’s not medically certified, standards are somewhat unclear.”

Cutting-Edge Studies and Biological Processes

At the same time, in a far-flung field of pioneering medical science, Chazot has been experimenting with brain cells, revealing various pathways for light-enhanced cell function. “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. Yet, experimental evidence has transformed his viewpoint.

The researcher primarily focuses on pharmaceutical solutions for brain disorders, but over 20 years ago, a doctor developing photonic antiviral treatment consulted his scientific background. “He created some devices so that we could work with them with cells and with fruit flies,” he says. “I was quite suspicious. The specific wavelength measured approximately 1070nm, that many assumed was biologically inert.”

What it did have going for it, nevertheless, was its efficient water penetration, meaning it could penetrate the body more deeply.

Mitochondrial Effects and Brain Health

Additional research indicated infrared affected cellular mitochondria. Mitochondria are the powerhouses of cells, producing fuel for biological processes. “Mitochondria exist throughout the body, particularly in neural cells,” explains the neuroscientist, who, as a neuroscientist, decided to focus the research on brain cells. “Research confirms improved brain blood flow with phototherapy, which is generally advantageous.”

With specific frequency application, cellular power plants create limited oxidative molecules. In low doses this substance, says Chazot, “activates protective proteins that safeguard mitochondria, protect cellular integrity and manage defective proteins.”

These processes show potential for neurological conditions: antioxidant, swelling control, and pro-autophagy – autophagy representing cellular waste disposal.

Present Investigation Status and Expert Assessments

The last time Chazot checked the literature on using the 1070 wavelength on human dementia patients, he reports, approximately 400 participants enrolled in multiple trials, incorporating his preliminary American studies