🔗 Share this article

Light therapy is certainly having a surge in popularity. You can now buy illuminated devices designed to address skin conditions and wrinkles to sore muscles and periodontal issues, the latest being a dental hygiene device outfitted with tiny red LEDs, described by its makers as “a significant discovery 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, where instead of hot coals (real or electric) heating the air, the infrared radiation heats your body itself. Based on supporter testimonials, it feels similar to a full-body light therapy session, boosting skin collagen, soothing sore muscles, relieving inflammation and persistent medical issues while protecting against dementia.

Research and Reservations

“It appears somewhat mystical,” says Paul Chazot, a scientist who has studied phototherapy extensively. Naturally, we know light influences biological functions. Our bodies produce vitamin D through sun exposure, crucial for strong bones, immune defense, and tissue repair. Light exposure controls our sleep-wake cycles, additionally, stimulating neurotransmitter and hormone production during daytime, and signaling the body to slow down for nighttime. Daylight-simulating devices are standard treatment for winter mood disorders to boost low mood in winter. Clearly, light energy is essential for optimal functioning.

Types of Light Therapy

While Sad lamps tend to use a mixture of light frequencies from the blue end of the spectrum, 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, identifying the optimal wavelength is crucial. Light is a form of electromagnetic radiation, extending from long-wavelength radiation to the highest-energy (gamma waves). Phototherapy, or light therapy employs mid-spectrum wavelengths, including invisible ultraviolet radiation, then visible light (all the colours we see in a rainbow) and finally infrared detectable with special equipment.

Ultraviolet treatment has been employed by skin specialists for decades to manage persistent skin disorders including eczema and psoriasis. It works on the immune system within cells, “and dampens down inflammation,” notes a dermatology expert. “Considerable data validates phototherapy.” UVA goes deeper into the skin than UVB, while the LEDs in consumer devices (typically emitting red, infrared or blue wavelengths) “tend to be a bit more superficial.”

Risk Assessment and Professional Supervision

Potential UVB consequences, like erythema or pigmentation, are recognized but medical equipment uses controlled narrow-band delivery – meaning smaller wavelengths – which minimises the risks. “Therapy is overseen by qualified practitioners, meaning intensity is regulated,” notes the specialist. Most importantly, the light sources are adjusted by technical experts, “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

Colored light diodes, he says, “don’t have strong medical applications, though they might benefit some issues.” Red light devices, some suggest, help boost blood circulation, oxygen utilization and cell renewal in the skin, and stimulate collagen production – a primary objective in youth preservation. “The evidence is there,” says Ho. “But it’s not conclusive.” Nevertheless, with numerous products on the market, “we’re uncertain whether commercial devices replicate research conditions. Optimal treatment times are unknown, ideal distance from skin surface, the risk-benefit ratio. There are lots of questions.”

Targeted Uses and Expert Opinions

Early blue-light applications focused on skin microbes, a microbe associated with acne. Scientific backing remains inadequate for regular prescription – despite the fact that, says Ho, “it’s often seen in medical spas or aesthetics practices.” Certain patients incorporate it into their regimen, he mentions, but if they’re buying a device for home use, “we recommend careful testing and security confirmation. If it’s not medically certified, the regulation is a bit grey.”

Innovative Investigations and Molecular Effects

At the same time, in advanced research areas, Chazot has been experimenting with brain cells, identifying a number of ways in which infrared can boost cellular health. “Virtually all experiments with specific wavelengths showed beneficial and safeguarding effects,” he reports. The numerous reported benefits have generated doubt regarding phototherapy – that results appear unrealistic. Yet, experimental evidence has transformed his viewpoint.

The scientist mainly develops medications for neurological conditions, though twenty years earlier, a physician creating light-based cold sore therapy requested his biological knowledge. “He designed tools for biological testing,” he says. “I was pretty sceptical. This particular frequency was around 1070 nanometers, that many assumed was biologically inert.”

What it did have going for it, nevertheless, was its ability to transmit through aqueous environments, meaning it could penetrate the body more deeply.

Mitochondrial Effects and Brain Health

Growing data suggested infrared influenced energy-producing organelles. Mitochondria produce ATP for cell function, generating energy for them to function. “All human cells contain mitochondria, particularly in neural cells,” notes the researcher, who prioritized neurological investigations. “Research confirms improved brain blood flow with phototherapy, which is always very good.”

With specific frequency application, energy organelles generate minimal reactive oxygen compounds. At controlled levels these compounds, says Chazot, “triggers guardian proteins that maintain organelle health, look after your cells and also deal with the unwanted proteins.”

These processes show potential for neurological conditions: oxidative protection, inflammation reduction, and pro-autophagy – autophagy being the process the cell uses to clear unwanted damaging proteins.

Present Investigation Status and Expert Assessments

Upon examining current studies on light therapy for dementia, he says, about 400 people were taking part in four studies, including his own initial clinical trials in the US