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Light therapy is clearly enjoying a surge in popularity. Consumers can purchase light-emitting tools for everything from dermatological concerns and fine lines along with sore muscles and gum disease, the latest being a toothbrush outfitted with miniature red light sources, described by its makers as “a breakthrough in personal mouth health.” Worldwide, 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, 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, stimulating skin elasticity, relaxing muscles, alleviating inflammatory responses and long-term ailments and potentially guarding against cognitive decline.

The Science and Skepticism

“It appears somewhat mystical,” notes a Durham University professor, who has researched light therapy for two decades. Certainly, some of light’s effects on our bodies are well established. Sunlight enables vitamin D production, essential for skeletal strength, immune function, and muscular health. Sunlight regulates our circadian rhythms, additionally, activating brain chemicals and hormonal responses in daylight, and preparing the body for rest as darkness falls. 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

Although mood lamps generally utilize blue-spectrum frequencies, most other light therapy devices deploy red or infrared light. In serious clinical research, such as Chazot’s investigations into the effects of infrared on brain cells, finding the right frequency is key. Photons represent electromagnetic waves, spanning from low-energy radio waves to high-energy gamma radiation. Phototherapy, or light therapy uses wavelengths around the middle of this spectrum, including invisible ultraviolet radiation, then visible light (all the colours we see in a rainbow) and then infrared (which we can see with night-vision goggles).

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. “Considerable data validates phototherapy.” UVA penetrates skin more deeply than UVB, while the LEDs in consumer devices (which generally deliver red, infrared or blue light) “typically have shallower penetration.”

Safety Protocols and Medical Guidance

UVB radiation effects, like erythema or pigmentation, are well known but in medical devices the light is delivered in a “narrow-band” form – meaning smaller wavelengths – that reduces potential hazards. “Treatment is monitored by medical staff, so the dosage is monitored,” says Ho. Most importantly, the lightbulbs are calibrated by medical technicians, “to ensure that the wavelength that’s being delivered is fit for purpose – as opposed to commercial tanning facilities, where it’s a bit unregulated, and wavelength accuracy isn’t verified.”

Consumer Devices and Evidence Gaps

Red and blue LEDs, he explains, “don’t have strong medical applications, though they might benefit some issues.” Red light devices, some suggest, enhance blood flow, oxygen absorption and cell renewal in the skin, and activate collagen formation – an important goal for anti-aging. “The evidence is there,” says Ho. “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. We don’t know the duration, ideal distance from skin surface, whether or not that will increase the risk versus the benefit. Many uncertainties remain.”

Treatment Areas and Specialist Views

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 – despite the fact that, explains the specialist, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he says, though when purchasing home devices, “we advise cautious experimentation and safety verification. Unless it’s a medical device, oversight remains ambiguous.”

Innovative Investigations and Molecular Effects

Meanwhile, in a far-flung field of pioneering medical science, researchers have been testing neural cells, revealing various pathways for light-enhanced cell function. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he says. Multiple claimed advantages have created skepticism toward light treatment – that results appear unrealistic. But his research has thoroughly changed his mind in that respect.

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 designed tools for biological testing,” he recalls. “I was pretty sceptical. This particular frequency was around 1070 nanometers, that many assumed was biologically inert.”

What it did have going for it, though, was its ability to transmit through aqueous environments, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

Additional research indicated infrared affected cellular mitochondria. Mitochondria are the powerhouses of cells, generating energy for them to function. “All human cells contain mitochondria, particularly in neural cells,” 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 generally advantageous.”

With 1070 treatment, mitochondria also produce a small amount of a molecule known as reactive oxygen species. In limited quantities these molecules, explains the expert, “activates protective proteins that safeguard mitochondria, protect cellular integrity and manage defective proteins.”

Such mechanisms indicate hope for cognitive disorders: antioxidant, inflammation reduction, and cellular cleanup – autophagy being the process the cell uses to clear unwanted damaging proteins.

Current Research Status and Professional Opinions

The last time Chazot checked the literature on using the 1070 wavelength on human dementia patients, he states, several hundred individuals participated in various investigations, incorporating his preliminary American studies