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Light therapy is certainly having a wave of attention. You can now buy light-emitting tools designed to address dermatological concerns and fine lines along with aching tissues and gum disease, the newest innovation is an oral care tool outfitted with tiny red LEDs, marketed by the company as “a breakthrough for domestic dental hygiene.” Worldwide, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. There are even infrared saunas available, that employ light waves rather than traditional heat sources, the infrared radiation heats your body itself. According to its devotees, the experience resembles using an LED facial mask, stimulating skin elasticity, easing muscle tension, relieving inflammation and chronic health conditions and potentially guarding against cognitive decline.

Research and Reservations

“It feels almost magical,” says a neuroscience expert, who has researched light therapy for two decades. Certainly, we know light influences biological functions. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Natural light synchronizes our biological clocks, too, stimulating neurotransmitter and hormone production during daytime, and signaling the body to slow down for nighttime. Sunlight-imitating lamps are standard treatment for winter mood disorders to combat seasonal emotional slumps. 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, finding the right frequency is key. Light is a form of electromagnetic radiation, extending from long-wavelength radiation to short-wavelength gamma rays. Phototherapy, or light therapy 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).

UV light has been used by medical dermatologists for many years to manage persistent skin disorders including eczema and psoriasis. It works on the immune system within cells, “and suppresses swelling,” explains Dr Bernard Ho. “Considerable data validates phototherapy.” UVA penetrates skin more deeply than UVB, whereas the LEDs we see on consumer light-therapy devices (typically emitting red, infrared or blue wavelengths) “generally affect surface layers.”

Risk Assessment and Professional Supervision

UVB radiation effects, including sunburn or skin darkening, are recognized but medical equipment uses controlled narrow-band delivery – indicating limited wavelength spectrum – which minimises the risks. “Treatment is monitored by medical staff, thus exposure is controlled,” explains the dermatologist. Most importantly, the light sources are adjusted by technical experts, “to guarantee appropriate wavelength emission – different from beauty salons, where it’s a bit unregulated, and we don’t really know what wavelengths are being used.”

Consumer Devices and Evidence Gaps

Colored light diodes, he notes, “aren’t really used in the medical sense, though they might benefit some issues.” Red light devices, some suggest, enhance blood flow, oxygen uptake and cell renewal in the skin, and promote collagen synthesis – a key aspiration in anti-ageing effects. “Studies are available,” comments the expert. “But it’s not conclusive.” In any case, with numerous products on the market, “we’re uncertain whether commercial devices replicate research conditions. 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.”

Treatment Areas and Specialist Views

Initial blue-light devices addressed acne bacteria, a microbe associated with acne. The evidence for its efficacy isn’t strong enough for it to be routinely prescribed by doctors – despite the fact that, says Ho, “it’s often seen in medical spas or aesthetics practices.” Individuals include it in their skincare practices, he mentions, though when purchasing home devices, “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 innovative scientific domains, Chazot has been experimenting with brain cells, revealing various pathways for light-enhanced cell function. “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. 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 physician creating light-based cold sore therapy requested his biological knowledge. “He created some devices so that we could work with them with cells and with fruit flies,” he recalls. “I was quite suspicious. It was an unusual wavelength of about 1070 nanometres, that many assumed was biologically inert.”

Its beneficial characteristic, though, was its efficient water penetration, meaning it could penetrate the body more deeply.

Mitochondrial Impact and Cognitive Support

Additional research indicated infrared affected cellular mitochondria. Mitochondria produce ATP for cell function, generating energy for them to function. “All human cells contain mitochondria, even within brain tissue,” notes the researcher, who, as a neuroscientist, decided to focus the research on brain cells. “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, explains the expert, “stimulates so-called chaperone proteins which look after your mitochondria, look after your cells and also deal with the unwanted proteins.”

These processes show potential for neurological conditions: free radical neutralization, swelling control, and waste removal – self-digestion mechanisms eliminating harmful elements.

Present Investigation Status and Expert Assessments

The last time Chazot checked the literature on using the 1070 wavelength on human dementia patients, he reports, several hundred individuals participated in various investigations, comprising his early research projects