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Phototherapy is certainly having a wave of attention. There are now available light-emitting tools designed to address dermatological concerns and fine lines as well as sore muscles and gum disease, the newest innovation is a dental hygiene device outfitted with tiny red LEDs, described by its makers as “a significant discovery in at-home oral care.” Worldwide, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. There are even infrared saunas available, where instead of hot coals (real or electric) heating the air, your body is warmed directly by infrared light. As claimed by enthusiasts, it’s like bathing in one of those LED-lit beauty masks, boosting skin collagen, soothing sore muscles, relieving inflammation and chronic health conditions and potentially guarding against cognitive decline.

Understanding the Evidence

“It sounds a bit like witchcraft,” notes a neuroscience expert, professor in neuroscience at Durham University and a convert to the value of light therapy. Of course, 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, stimulating neurotransmitter and hormone production during daytime, and winding down bodily functions for sleep as it fades into night. Sunlight-imitating lamps are a common remedy for people with seasonal affective disorder (Sad) to elevate spirits during colder months. Clearly, light energy is essential for optimal functioning.

Various Phototherapy Approaches

Whereas seasonal affective disorder devices typically employ blue-range light, consumer light therapy products mostly feature red and infrared emissions. In serious clinical research, such as Chazot’s investigations into the effects of infrared on brain cells, determining the precise frequency is essential. Photons represent electromagnetic waves, spanning from low-energy radio waves to the highest-energy (gamma waves). Therapeutic light application uses wavelengths around the middle of this spectrum, with ultraviolet representing the higher energy invisible light, then the visible spectrum we perceive as colors and finally infrared detectable with special equipment.

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,” says Dr Bernard Ho. “There’s lots of evidence for phototherapy.” UVA penetrates skin more deeply than UVB, whereas the LEDs we see on consumer light-therapy devices (usually producing colored light emissions) “typically have shallower penetration.”

Risk Assessment and Professional Supervision

Potential UVB consequences, such as burning or tanning, are understood but clinical devices employ restricted wavelength ranges – meaning smaller wavelengths – that reduces potential hazards. “Treatment is monitored by medical staff, thus exposure is controlled,” notes the specialist. Most importantly, the lightbulbs are calibrated by medical technicians, “to confirm suitable light frequency output – different from beauty salons, where oversight might be limited, and emission spectra aren’t confirmed.”

Home Devices and Scientific Uncertainty

Red and blue light sources, he explains, “aren’t typically employed clinically, though they might benefit some issues.” Red LEDs, it is proposed, enhance blood flow, oxygen absorption and dermal rejuvenation, and promote collagen synthesis – a primary objective in youth preservation. “Studies are available,” comments the expert. “Although it’s not strong.” Regardless, given the plethora of available tools, “we don’t know whether or not the lights emitted are reflective of the research that has been done. Optimal treatment times are unknown, proper positioning requirements, if benefits outweigh potential risks. There are lots of questions.”

Specific Applications and Professional Perspectives

Early blue-light applications focused on skin microbes, bacteria linked to pimples. Research support isn’t sufficient for standard medical recommendation – even though, explains the specialist, “it’s often seen in medical spas or aesthetics practices.” Certain patients incorporate it into their regimen, he observes, however for consumer products, “we just tell them to try it carefully and to make sure it has been assessed for safety. If it’s not medically certified, the regulation is a bit grey.”

Innovative Investigations and Molecular Effects

At the same time, in advanced research areas, researchers have been testing neural cells, identifying a number of ways in which infrared can boost cellular health. “Virtually all experiments with specific wavelengths showed beneficial and safeguarding effects,” he states. The numerous reported benefits have generated doubt regarding phototherapy – 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 created some devices so that we could work with them with cells and with fruit flies,” he explains. “I was quite suspicious. The specific wavelength measured approximately 1070nm, that nobody believed did anything biological.”

The advantage it possessed, however, was its efficient water penetration, meaning it could penetrate the body more deeply.

Mitochondrial Effects and Brain Health

More evidence was emerging at the time that infrared light targeted the mitochondria in cells. Mitochondria produce ATP for cell function, creating power for cellular operations. “Every cell in your body has mitochondria, including the brain,” notes the researcher, who prioritized neurological investigations. “It has been shown that in humans this light therapy increases blood flow into the brain, which is consistently beneficial.”

With specific frequency application, mitochondria also produce a small amount of a molecule known as reactive oxygen species. In low doses this substance, notes the scientist, “triggers guardian proteins that maintain organelle health, look after your cells and also deal with the unwanted proteins.”

Such mechanisms indicate hope for cognitive disorders: free radical neutralization, anti-inflammatory, and waste removal – self-digestion mechanisms eliminating harmful elements.

Ongoing Study Progress and Specialist Evaluations

When recently reviewing 1070nm research for cognitive decline, he reports, approximately 400 participants enrolled in multiple trials, including his own initial clinical trials in the US