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Phototherapy is certainly having a surge in popularity. There are now available light-emitting tools designed to address skin conditions and wrinkles as well as muscle pain and oral inflammation, the newest innovation is an oral care tool equipped with miniature red light sources, described by its makers as “a major advance in personal mouth health.” Worldwide, 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, the thermal energy targets your tissues immediately. According to its devotees, the experience resembles using an LED facial mask, enhancing collagen production, soothing sore muscles, alleviating inflammatory responses and chronic health conditions and potentially guarding against cognitive decline.

The Science and Skepticism

“It sounds a bit like witchcraft,” notes Paul Chazot, who has researched light therapy for two decades. Naturally, 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, as well, triggering the release of neurochemicals and hormones while we are awake, and preparing the body for rest as darkness falls. Artificial sun lamps are standard treatment for winter mood disorders to boost low mood in winter. Undoubtedly, light plays a vital role in human health.

Various Phototherapy Approaches

Although mood lamps generally utilize blue-spectrum frequencies, the majority of phototherapy tools use red or near-infrared wavelengths. In rigorous scientific studies, 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, spanning from low-energy radio waves to the highest-energy (gamma waves). Therapeutic light application utilizes intermediate light frequencies, including invisible ultraviolet radiation, 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 modulates intracellular immune mechanisms, “and dampens down inflammation,” explains a dermatology expert. “There’s lots of evidence for phototherapy.” UVA goes deeper into the skin than UVB, while the LEDs in consumer devices (which generally deliver red, infrared or blue light) “typically have shallower penetration.”

Safety Considerations and Medical Oversight

Potential UVB consequences, 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 decreases danger. “Treatment is monitored by medical staff, meaning intensity is regulated,” notes the specialist. Most importantly, the devices are tuned by qualified personnel, “to ensure that the wavelength that’s being delivered is fit for purpose – different from beauty salons, where oversight might be limited, and we don’t really know what wavelengths are being used.”

Consumer Devices and Evidence Gaps

Red and blue LEDs, he says, “don’t have strong medical applications, though they might benefit some issues.” Red LEDs, it is proposed, help boost blood circulation, oxygen absorption and cell renewal in the skin, and stimulate collagen production – a key aspiration in anti-ageing effects. “Research exists,” comments the expert. “But it’s not conclusive.” In any case, 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. Appropriate exposure periods aren’t established, how close the lights should be to the skin, if benefits outweigh potential risks. There are lots of questions.”

Targeted Uses and Expert Opinions

Early blue-light applications focused on skin microbes, bacteria linked to pimples. Research support isn’t sufficient for standard medical recommendation – even though, says Ho, “it’s often seen in medical spas or aesthetics practices.” Certain patients incorporate it into their regimen, he observes, though when purchasing home devices, “we advise cautious experimentation and safety verification. Unless it’s a medical device, the regulation is a bit grey.”

Innovative Investigations and Molecular Effects

Meanwhile, in innovative scientific domains, scientists have been studying cerebral tissue, identifying a number of ways in which infrared can boost cellular health. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” 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. But his research has thoroughly changed his mind in that respect.

The researcher primarily focuses on pharmaceutical solutions for brain disorders, however two decades past, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He developed equipment for cellular and insect experiments,” he says. “I remained doubtful. It was an unusual wavelength of about 1070 nanometres, that many assumed was biologically inert.”

The advantage it possessed, though, was that it travelled through water easily, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

Additional research indicated infrared affected cellular mitochondria. These organelles generate cellular energy, generating energy for them to function. “Every cell in your body has mitochondria, including the brain,” explains the neuroscientist, who, as a neuroscientist, decided to focus the research on brain cells. “Studies demonstrate enhanced cerebral circulation with light treatment, which is always very good.”

With specific frequency application, cellular power plants create limited oxidative molecules. At controlled levels these compounds, explains the expert, “stimulates so-called chaperone proteins which look after your mitochondria, preserve cell function and eliminate damaged proteins.”

All of these mechanisms appear promising for treating a brain disease: antioxidant, inflammation reduction, and waste removal – self-digestion mechanisms eliminating harmful elements.

Present Investigation Status and Expert Assessments

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