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Light-based treatment is certainly having a surge in popularity. There are now available glowing gadgets designed to address complexion problems and aging signs as well as sore muscles and periodontal issues, the latest being a dental hygiene device enhanced with tiny red LEDs, described by its makers as “a significant discovery for domestic dental hygiene.” Internationally, 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 thermal energy targets your tissues immediately. Based on supporter testimonials, it’s like bathing in one of those LED-lit beauty masks, boosting skin collagen, easing muscle tension, relieving inflammation and long-term ailments as well as supporting brain health.

The Science and Skepticism

“It appears somewhat mystical,” observes Paul Chazot, professor in neuroscience at Durham University and a convert to the value of light therapy. Naturally, certain impacts of light on human physiology are proven. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Natural light synchronizes our biological clocks, as well, activating brain chemicals and hormonal responses in daylight, 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.

Types of Light Therapy

Whereas seasonal affective disorder devices typically employ blue-range light, consumer light therapy products mostly feature red and infrared emissions. In serious clinical research, including research on infrared’s impact on neural cells, determining the precise frequency is essential. Light is a form of electromagnetic radiation, spanning from low-energy radio waves to high-energy gamma radiation. Therapeutic light application uses wavelengths around the middle of this spectrum, including invisible ultraviolet radiation, then visible light (all the colours we see in a rainbow) and infrared light visible through night vision technology.

UV light has been used by medical dermatologists for many years for addressing long-term dermatological issues like vitiligo. It affects cellular immune responses, “and dampens down inflammation,” notes a skin specialist. “Considerable data validates phototherapy.” UVA reaches deeper skin layers compared to UVB, in contrast to LEDs in commercial products (which generally deliver red, infrared or blue light) “tend to be a bit more superficial.”

Safety Protocols and Medical Guidance

The side-effects of UVB exposure, such as burning or tanning, are well known but in medical devices the light is delivered in a “narrow-band” form – signifying focused frequency bands – which minimises the risks. “It’s supervised by a healthcare professional, so the dosage is monitored,” says Ho. Essentially, the devices are tuned by qualified personnel, “to ensure that the wavelength that’s being delivered is fit for purpose – unlike in tanning salons, where regulations may be lax, and emission spectra aren’t confirmed.”

Commercial Products and Research Limitations

Red and blue LEDs, he explains, “don’t have strong medical applications, but they may help with certain conditions.” Red light devices, some suggest, enhance blood flow, oxygen absorption and cell renewal in the skin, and promote collagen synthesis – a primary objective in youth preservation. “Research exists,” comments the expert. “However, it’s limited.” Regardless, with numerous products on the market, “it’s unclear if device outputs match study parameters. Optimal treatment times are unknown, proper positioning requirements, whether or not that will increase the risk versus the benefit. Numerous concerns persist.”

Targeted Uses and Expert Opinions

One of the earliest blue-light products targeted Cutibacterium acnes, bacteria linked to pimples. The evidence for its efficacy isn’t strong enough for it to be routinely prescribed by doctors – even though, notes the dermatologist, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he mentions, but if they’re buying a device for home use, “we recommend careful testing and security confirmation. Without proper medical classification, the regulation is a bit grey.”

Innovative Investigations and Molecular Effects

Meanwhile, in advanced research areas, Chazot has been experimenting with brain cells, identifying a number of ways in which infrared can boost cellular health. “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 results appear unrealistic. However, scientific investigation has altered his perspective.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, however two decades past, a physician creating light-based cold sore therapy requested his biological knowledge. “He developed equipment for cellular and insect experiments,” he recalls. “I was pretty sceptical. It was an unusual wavelength of about 1070 nanometres, which most thought had no biological effect.”

What it did have going for it, though, was that it travelled through water easily, allowing substantial bodily penetration.

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, producing fuel for biological processes. “Every cell in your body has mitochondria, even within brain tissue,” explains the neuroscientist, who concentrated on cerebral applications. “Studies demonstrate enhanced cerebral circulation with light treatment, which is consistently beneficial.”

Using 1070nm wavelength, 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, protect cellular integrity and manage defective proteins.”

All of these mechanisms appear promising for treating a brain disease: free radical neutralization, anti-inflammatory, and pro-autophagy – autophagy representing cellular waste disposal.

Ongoing Study Progress and Specialist Evaluations

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, incorporating his preliminary American studies