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Phototherapy is certainly having a moment. There are now available illuminated devices targeting issues like complexion problems and aging signs as well as aching tissues and gum disease, the newest innovation is a dental hygiene device enhanced with small red light diodes, promoted by the creators 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. You can even go and sit in an infrared sauna, where instead of hot coals (real or electric) heating the air, your body is warmed directly by infrared light. Based on supporter testimonials, it’s like bathing in one of those LED-lit beauty masks, enhancing collagen production, easing muscle tension, relieving inflammation and long-term ailments while protecting against dementia.

Research and Reservations

“It sounds a bit like witchcraft,” notes a Durham University professor, who has researched light therapy for two decades. Of course, certain impacts of light on human physiology are proven. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Sunlight regulates our circadian rhythms, too, activating brain chemicals and hormonal responses in daylight, and winding down bodily functions for sleep as it fades into night. Artificial sun lamps frequently help individuals with seasonal depression to combat seasonal emotional slumps. So there’s no doubt we need light energy to function well.

Various Phototherapy Approaches

Whereas seasonal affective disorder devices typically employ blue-range light, the majority of phototherapy tools use red or near-infrared wavelengths. In rigorous scientific studies, including research on infrared’s impact on neural cells, determining the precise frequency is essential. Light is a form of electromagnetic radiation, spanning from low-energy radio waves to short-wavelength gamma rays. Light-based treatment uses wavelengths around the middle of this spectrum, the highest energy of those being invisible ultraviolet, then the visible spectrum we perceive as colors and infrared light visible through night vision technology.

Dermatologists have utilized UV therapy for extensive periods to treat chronic skin conditions such as eczema, psoriasis and vitiligo. It works on the immune system within cells, “and dampens down inflammation,” notes a skin specialist. “Considerable data validates phototherapy.” UVA goes deeper into the skin than UVB, whereas the LEDs we see on consumer light-therapy devices (which generally deliver red, infrared or blue light) “typically have shallower penetration.”

Risk Assessment and Professional Supervision

Potential UVB consequences, like erythema or pigmentation, are understood but clinical devices employ restricted wavelength ranges – signifying focused frequency bands – which minimises the risks. “Therapy is overseen by qualified practitioners, so the dosage is monitored,” says Ho. And crucially, the lightbulbs are calibrated by medical technicians, “to confirm suitable light frequency output – as opposed to commercial tanning facilities, where oversight might be limited, and emission spectra aren’t confirmed.”

Commercial Products and Research Limitations

Red and blue light sources, he says, “aren’t typically employed clinically, though they might benefit some issues.” Red light devices, some suggest, help boost blood circulation, oxygen absorption and skin cell regeneration, and activate collagen formation – an important goal for anti-aging. “Research exists,” states the dermatologist. “But it’s not conclusive.” Nevertheless, with numerous products on the market, “we don’t know whether or not the lights emitted are reflective of the research that has been done. Optimal treatment times are unknown, how close the lights should be to the skin, the risk-benefit ratio. Many uncertainties remain.”

Specific Applications and Professional Perspectives

One of the earliest blue-light products targeted Cutibacterium acnes, microorganisms connected to breakouts. The evidence for its efficacy isn’t strong enough for it to be routinely prescribed by doctors – even though, says Ho, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he observes, but if they’re buying a device for home use, “we just tell them to try it carefully and to make sure it has been assessed for safety. Without proper medical classification, oversight remains ambiguous.”

Innovative Investigations and Molecular Effects

At the same time, in advanced research areas, Chazot has been experimenting with brain cells, discovering multiple mechanisms for infrared’s cellular benefits. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he says. The numerous reported benefits have generated doubt regarding phototherapy – that claims seem exaggerated. However, scientific investigation has altered his perspective.

The researcher primarily focuses on pharmaceutical solutions for brain disorders, 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 explains. “I was pretty sceptical. It was an unusual wavelength of about 1070 nanometres, which most thought had no biological effect.”

Its beneficial characteristic, however, was its efficient water penetration, allowing substantial bodily penetration.

Cellular Energy and Neurological Benefits

Additional research indicated infrared affected cellular mitochondria. Mitochondria are the powerhouses of cells, producing fuel for biological processes. “Mitochondria exist throughout the body, including the brain,” notes the researcher, who prioritized neurological investigations. “Research confirms improved brain blood flow with phototherapy, which is generally advantageous.”

With specific frequency application, energy organelles generate minimal reactive oxygen compounds. In limited quantities these molecules, says Chazot, “stimulates so-called chaperone proteins which look after your mitochondria, protect cellular integrity and manage defective proteins.”

Such mechanisms indicate hope for cognitive disorders: oxidative protection, inflammation reduction, and waste removal – autophagy representing cellular waste disposal.

Current Research Status and Professional Opinions

Upon examining current studies on light therapy for dementia, he states, about 400 people were taking part in four studies, comprising his early research projects