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Phototherapy is clearly enjoying a surge in popularity. You can now buy glowing gadgets targeting issues like dermatological concerns and fine lines along with aching tissues and oral inflammation, the newest innovation is a dental hygiene device equipped with tiny red LEDs, marketed by the company as “a major advance in personal mouth health.” Globally, the industry reached $1 billion in 2024 and is forecast to expand to $1.8 billion by 2035. There are even infrared saunas available, that employ light waves rather than traditional heat sources, the infrared radiation heats your body itself. As claimed by enthusiasts, it feels similar to a full-body light therapy session, stimulating skin elasticity, easing muscle tension, reducing swelling and long-term ailments and potentially guarding against cognitive decline.

Research and Reservations

“It sounds a bit like witchcraft,” observes Paul Chazot, professor in neuroscience at Durham University and a convert to the value of light therapy. Naturally, some of light’s effects on our bodies are well established. Our bodies produce vitamin D through sun exposure, crucial for strong bones, immune defense, and tissue repair. Sunlight regulates our circadian rhythms, too, 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. Clearly, light energy is essential for optimal functioning.

Various Phototherapy Approaches

While Sad lamps tend to use a mixture of light frequencies from the blue end of the spectrum, 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, identifying the optimal wavelength is crucial. Light constitutes electromagnetic energy, spanning from low-energy radio waves to the highest-energy (gamma waves). Therapeutic light application utilizes intermediate light frequencies, including invisible ultraviolet radiation, followed by visible light encompassing rainbow colors and then infrared (which we can see with night-vision goggles).

Dermatologists have utilized UV therapy for extensive periods for addressing long-term dermatological issues like vitiligo. It modulates intracellular immune mechanisms, “and reduces inflammatory processes,” explains Dr Bernard Ho. “There’s lots of evidence for phototherapy.” UVA reaches deeper skin layers compared to UVB, while the LEDs in consumer devices (which generally deliver red, infrared or blue light) “generally affect surface layers.”

Risk Assessment and Professional Supervision

UVB radiation effects, like erythema or pigmentation, are well known but in medical devices the light is delivered in a “narrow-band” form – signifying focused frequency bands – 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 – as opposed to commercial tanning facilities, where it’s a bit unregulated, and we don’t really know what wavelengths are being used.”

Home Devices and Scientific Uncertainty

Red and blue light sources, he says, “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 – an important goal for anti-aging. “The evidence is there,” comments the expert. “Although it’s not strong.” Nevertheless, amid the sea of devices now available, “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, whether or not that will increase the risk versus the benefit. There are lots of questions.”

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 – although, explains the specialist, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, 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

Meanwhile, in innovative scientific domains, researchers have been testing neural cells, discovering multiple mechanisms for infrared’s cellular benefits. “Pretty much everything I did with the light at that particular wavelength was positive and protective,” he says. The numerous reported benefits have generated doubt regarding phototherapy – that it’s too good to be true. 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 says. “I was quite suspicious. The specific wavelength measured approximately 1070nm, which most thought had no biological effect.”

The advantage it possessed, however, was its efficient water penetration, allowing substantial bodily 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, generating energy for them to function. “All human cells contain mitochondria, including the brain,” says Chazot, who, as a neuroscientist, decided to focus the research on brain cells. “Research confirms improved brain blood flow with phototherapy, which is generally advantageous.”

With specific frequency application, energy organelles generate minimal reactive oxygen compounds. In low doses this substance, notes the scientist, “triggers guardian proteins that maintain organelle health, protect cellular integrity and manage defective proteins.”

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

Ongoing Study Progress and Specialist Evaluations

When recently reviewing 1070nm research for cognitive decline, he states, approximately 400 participants enrolled in multiple trials, comprising his early research projects