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Light therapy is clearly enjoying a moment. You can now buy light-emitting tools for everything from dermatological concerns and fine lines to aching tissues and oral inflammation, the newest innovation is a toothbrush equipped with miniature red light sources, promoted by the creators as “a major advance in at-home oral care.” Globally, 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. As claimed by enthusiasts, the experience resembles using an LED facial mask, boosting skin collagen, soothing sore muscles, alleviating inflammatory responses and persistent medical issues and potentially guarding against cognitive decline.

Understanding the Evidence

“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, certain impacts of light on human physiology are proven. Sunlight helps us make vitamin D, crucial for strong bones, immune defense, and tissue repair. Light exposure controls our sleep-wake cycles, additionally, triggering the release of neurochemicals and hormones while we are awake, and signaling the body to slow down for nighttime. Daylight-simulating devices are standard treatment for winter mood disorders to boost low mood in winter. So there’s no doubt we need light energy to function well.

Types of Light Therapy

While Sad lamps tend to use a mixture of light frequencies from the blue end of the spectrum, consumer light therapy products mostly feature red and infrared emissions. During advanced medical investigations, including research on infrared’s impact on neural cells, identifying the optimal wavelength is crucial. Light constitutes electromagnetic energy, spanning from low-energy radio waves to high-energy gamma radiation. Therapeutic light application uses wavelengths around the middle of this spectrum, the highest energy of those being invisible ultraviolet, then visible light (all the colours we see in a rainbow) 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 affects cellular immune responses, “and suppresses swelling,” says a dermatology expert. “Substantial research supports light therapy.” UVA goes deeper into the skin than UVB, while the LEDs in consumer devices (usually producing colored light emissions) “typically have shallower penetration.”

Risk Assessment and Professional Supervision

The side-effects of UVB exposure, such as burning or tanning, are recognized but medical equipment uses controlled narrow-band delivery – meaning smaller wavelengths – which minimises the risks. “Therapy is overseen by qualified practitioners, thus exposure is controlled,” says Ho. Essentially, the lightbulbs are calibrated by medical technicians, “to confirm suitable light frequency output – as opposed to commercial tanning facilities, where regulations may be lax, and wavelength accuracy isn’t verified.”

Commercial Products and Research Limitations

Colored light diodes, he explains, “don’t have strong medical applications, but could assist with specific concerns.” Red wavelength therapy, proponents claim, improve circulatory function, oxygen uptake and dermal rejuvenation, and activate collagen formation – a key aspiration in anti-ageing effects. “Studies are available,” states the dermatologist. “Although it’s not strong.” In any case, amid the sea of devices now available, “it’s unclear if device outputs match study parameters. Appropriate exposure periods aren’t established, how close the lights should be to the skin, if benefits outweigh potential risks. Many uncertainties remain.”

Targeted Uses and Expert Opinions

Early blue-light applications focused on skin microbes, 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.” Certain patients incorporate it into their regimen, he observes, however for consumer products, “we advise cautious experimentation and safety verification. If it’s not medically certified, 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 it’s too good to be true. Yet, experimental evidence has transformed his viewpoint.

The scientist mainly develops medications for neurological conditions, 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 explains. “I remained doubtful. This particular frequency was around 1070 nanometers, that many assumed was biologically inert.”

What it did have going for it, nevertheless, was its efficient water penetration, enabling deeper tissue penetration.

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. “All human cells contain mitochondria, even within brain tissue,” explains the neuroscientist, who prioritized neurological investigations. “It has been shown that in humans this light therapy increases blood flow into the brain, which is consistently beneficial.”

Using 1070nm wavelength, cellular power plants create limited oxidative molecules. In low doses this substance, says Chazot, “triggers guardian proteins that maintain organelle health, protect cellular integrity and manage defective proteins.”

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

Present Investigation Status and Expert Assessments

The last time Chazot checked the literature on using the 1070 wavelength on human dementia patients, he reports, about 400 people were taking part in four studies, including his own initial clinical trials in the US