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Light therapy is certainly having a moment. You can now buy light-emitting tools designed to address dermatological concerns and fine lines as well as muscle pain and gum disease, the newest innovation is a dental hygiene device equipped with miniature red light sources, promoted by the creators 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. Options include full-body infrared sauna sessions, that employ light waves rather than traditional heat sources, the infrared radiation heats your body itself. Based on supporter testimonials, the experience resembles using an LED facial mask, boosting skin collagen, easing muscle tension, alleviating inflammatory responses and persistent medical issues as well as supporting brain health.

Understanding the Evidence

“It feels almost magical,” notes a neuroscience expert, professor in neuroscience at Durham University and a convert to the value of light therapy. Of course, we know light influences biological functions. Sunlight enables vitamin D production, essential for skeletal strength, immune function, and muscular health. 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 frequently help individuals with seasonal depression to boost low mood in winter. Clearly, light energy is essential for optimal functioning.

Different Light Modalities

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. During advanced medical investigations, like examinations of infrared influence on cerebral tissue, finding the right frequency is key. Photons represent electromagnetic waves, spanning from low-energy radio waves to high-energy gamma radiation. Light-based treatment uses wavelengths around the middle of this spectrum, the highest energy of those being invisible ultraviolet, then the visible spectrum we perceive as colors and then infrared (which we can see with night-vision goggles).

Ultraviolet treatment has been employed by skin specialists for decades for addressing long-term dermatological issues like vitiligo. It works on the immune system within cells, “and dampens down inflammation,” explains a skin specialist. “There’s lots of evidence for 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

UVB radiation effects, such as burning or tanning, are recognized but medical equipment uses controlled narrow-band delivery – indicating limited wavelength spectrum – which minimises the risks. “Therapy is overseen by qualified practitioners, meaning intensity is regulated,” notes the specialist. Most importantly, the lightbulbs are calibrated by medical technicians, “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.”

Home Devices and Scientific Uncertainty

Colored light diodes, he notes, “don’t have strong medical applications, but could assist with specific concerns.” Red light devices, some suggest, enhance blood flow, oxygen absorption and skin cell regeneration, and stimulate collagen production – an important goal for anti-aging. “Research exists,” states the dermatologist. “Although it’s not strong.” In any case, with numerous products on the market, “we’re uncertain whether commercial devices replicate research conditions. Appropriate exposure periods aren’t established, proper positioning requirements, the risk-benefit ratio. Numerous concerns persist.”

Targeted Uses and Expert Opinions

One of the earliest blue-light products targeted Cutibacterium acnes, microorganisms connected to breakouts. Scientific backing remains inadequate for regular prescription – although, notes the dermatologist, “it’s commonly used in cosmetic clinics.” Individuals include it in their skincare practices, he mentions, however for consumer products, “we advise cautious experimentation and safety verification. Without proper medical classification, standards are somewhat unclear.”

Innovative Investigations and Molecular Effects

Simultaneously, in advanced research areas, Chazot has been experimenting with brain cells, discovering multiple mechanisms for infrared’s cellular benefits. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he states. The numerous reported benefits have generated doubt regarding phototherapy – that it’s too good to be true. However, scientific investigation has altered his perspective.

The scientist mainly develops medications for neurological conditions, but over 20 years ago, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He created some devices so that we could work with them with cells and with fruit flies,” he explains. “I remained doubtful. It was an unusual wavelength of about 1070 nanometres, that many assumed was biologically inert.”

What it did have going for it, though, was its ability to transmit through aqueous environments, enabling deeper tissue 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, producing fuel for biological processes. “Mitochondria exist throughout the body, even within brain tissue,” explains the neuroscientist, who prioritized neurological investigations. “Research confirms improved brain blood flow with phototherapy, which is consistently beneficial.”

Using 1070nm wavelength, mitochondria also produce a small amount of a molecule known as reactive oxygen species. In limited quantities these molecules, notes the scientist, “activates protective proteins that safeguard mitochondria, preserve cell function and eliminate damaged proteins.”

All of these mechanisms appear promising for treating a brain disease: antioxidant, inflammation reduction, and waste removal – 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 says, several hundred individuals participated in various investigations, comprising his early research projects