🔗 Share this article

Light therapy is clearly enjoying a surge in popularity. You can now buy light-emitting tools designed to address complexion problems and aging signs to sore muscles and oral inflammation, recently introduced is a dental hygiene device equipped with small red light diodes, marketed by the company as “a major advance in personal mouth health.” Worldwide, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. Options include full-body infrared sauna sessions, which use infrared light to warm the body directly, 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, reducing swelling and long-term ailments and potentially guarding against cognitive decline.

Understanding the Evidence

“It sounds a bit like witchcraft,” notes a neuroscience expert, a scientist who has studied phototherapy extensively. Of course, some of light’s effects on our bodies are well established. Our bodies produce vitamin D through sun exposure, needed for bone health, immunity, muscles and more. Light exposure controls our sleep-wake cycles, too, triggering the release of neurochemicals and hormones while we are awake, and preparing the body for rest as darkness falls. Daylight-simulating devices are a common remedy for people with seasonal affective disorder (Sad) to boost low mood in winter. Clearly, light energy is essential for optimal functioning.

Types of Light Therapy

Although mood lamps generally utilize blue-spectrum frequencies, most other light therapy devices deploy red or infrared light. During advanced medical investigations, such as Chazot’s investigations into the effects of infrared on brain cells, finding the right frequency is key. Photons represent electromagnetic waves, extending from long-wavelength radiation to the highest-energy (gamma waves). Therapeutic light application uses wavelengths around the middle of this spectrum, including invisible ultraviolet radiation, then the visible spectrum we perceive as colors and infrared light visible through night vision technology.

Dermatologists have utilized UV therapy for extensive periods for addressing long-term dermatological issues like vitiligo. It affects cellular immune responses, “and dampens down inflammation,” says Dr Bernard Ho. “Substantial research supports light therapy.” UVA goes deeper into the skin than UVB, in contrast to LEDs in commercial products (usually producing colored light emissions) “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 – indicating limited wavelength spectrum – which decreases danger. “Treatment is monitored by medical staff, meaning intensity is regulated,” says Ho. And crucially, the light sources are adjusted by technical experts, “to confirm suitable light frequency output – unlike in tanning salons, where oversight might be limited, and emission spectra aren’t confirmed.”

Home Devices and Scientific Uncertainty

Colored light diodes, he explains, “aren’t really used in the medical sense, but they may help with certain conditions.” Red wavelength therapy, proponents claim, 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, given the plethora of available tools, “it’s unclear if device outputs match study parameters. We don’t know the duration, proper positioning requirements, if benefits outweigh potential risks. There are lots of questions.”

Specific Applications and Professional Perspectives

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 – although, notes the dermatologist, “it’s frequently employed in beauty centers.” Certain patients incorporate it into their regimen, he observes, but if they’re buying a device for home use, “we just tell them to try it carefully and to make sure it has been assessed for safety. If it’s not medically certified, standards are somewhat unclear.”

Innovative Investigations and Molecular Effects

At the same time, in a far-flung field of pioneering medical science, Chazot has been experimenting with brain cells, revealing various pathways for light-enhanced cell function. “Virtually all experiments with specific wavelengths showed beneficial and safeguarding effects,” he says. The numerous reported benefits have generated doubt regarding phototherapy – that results appear unrealistic. Yet, experimental evidence has transformed his viewpoint.

The researcher primarily focuses on pharmaceutical solutions for brain disorders, though twenty years earlier, a doctor developing photonic antiviral treatment consulted his scientific background. “He designed tools for biological testing,” he explains. “I was quite suspicious. It was an unusual wavelength of about 1070 nanometres, which most thought had no biological effect.”

Its beneficial characteristic, however, was its ability to transmit through aqueous environments, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

More evidence was emerging at the time that infrared light targeted the mitochondria in cells. These organelles generate cellular energy, producing fuel for biological processes. “Every cell in your body has mitochondria, even within brain tissue,” notes the researcher, who concentrated on cerebral applications. “It has been shown that in humans this light therapy increases blood flow into the brain, which is generally advantageous.”

Using 1070nm wavelength, cellular power plants create limited oxidative molecules. At controlled levels these compounds, notes the scientist, “activates protective proteins that safeguard mitochondria, protect cellular integrity and manage defective proteins.”

These processes show potential for neurological conditions: oxidative protection, swelling control, 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 states, about 400 people were taking part in four studies, incorporating his preliminary American studies