🔗 Share this article

Light-based treatment is clearly enjoying a wave of attention. There are now available illuminated devices for everything from skin conditions and wrinkles as well as sore muscles and periodontal issues, the latest being a toothbrush outfitted with miniature red light sources, promoted by the creators as “a significant discovery in personal mouth health.” Internationally, the sector valued at $1bn last year is expected to increase to $1.8bn within the next decade. There are even infrared saunas available, where instead of hot coals (real or electric) heating the air, your body is warmed directly by infrared light. As claimed by enthusiasts, the experience resembles using an LED facial mask, boosting skin collagen, easing muscle tension, reducing swelling and long-term ailments while protecting against dementia.

The Science and Skepticism

“It sounds a bit like witchcraft,” says Paul Chazot, 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. Light exposure controls our sleep-wake cycles, additionally, activating brain chemicals and hormonal responses in daylight, and signaling the body to slow down for nighttime. Artificial sun lamps frequently help individuals with seasonal depression to boost low mood in winter. Undoubtedly, light plays a vital role in human health.

Different Light Modalities

Whereas seasonal affective disorder devices typically employ blue-range light, most other light therapy devices deploy red or infrared light. In serious clinical research, such as Chazot’s investigations into the effects of infrared on brain cells, identifying the optimal wavelength is crucial. Light constitutes electromagnetic energy, spanning from low-energy radio waves to the highest-energy (gamma waves). Therapeutic light application 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).

Dermatologists have utilized UV therapy for extensive periods to manage persistent skin disorders including eczema and psoriasis. It affects cellular immune responses, “and reduces inflammatory processes,” explains a skin specialist. “There’s lots of evidence for phototherapy.” UVA penetrates skin more deeply than UVB, in contrast to LEDs in commercial products (typically emitting red, infrared or blue wavelengths) “typically have shallower penetration.”

Safety Protocols and Medical Guidance

Potential UVB consequences, like erythema or pigmentation, are well known but in medical devices the light is delivered in a “narrow-band” form – signifying focused frequency bands – that reduces potential hazards. “Therapy is overseen by qualified practitioners, so the dosage is monitored,” notes the specialist. Essentially, the devices are tuned by qualified personnel, “to confirm suitable light frequency output – as opposed to commercial tanning facilities, where oversight might be limited, and we don’t really know what wavelengths are being used.”

Consumer Devices and Evidence Gaps

Red and blue light sources, he explains, “aren’t typically employed clinically, but could assist with specific concerns.” Red LEDs, it is proposed, improve circulatory function, oxygen utilization and dermal rejuvenation, and promote collagen synthesis – a key aspiration in anti-ageing effects. “The evidence is there,” says Ho. “But it’s not conclusive.” Regardless, with numerous products on the market, “we’re uncertain whether commercial devices replicate research conditions. Appropriate exposure periods aren’t established, how close the lights should be to the skin, if benefits outweigh potential risks. There are lots of questions.”

Treatment Areas and Specialist Views

One of the earliest blue-light products targeted Cutibacterium acnes, microorganisms connected to breakouts. 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 commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he observes, however for consumer products, “we just tell them to try it carefully and to make sure it has been assessed for safety. Unless it’s a medical device, oversight remains ambiguous.”

Innovative Investigations and Molecular Effects

Simultaneously, in innovative scientific domains, scientists have been studying cerebral tissue, revealing various pathways for light-enhanced cell function. “Virtually all experiments with specific wavelengths showed beneficial and safeguarding effects,” he says. Multiple claimed advantages have created skepticism toward light treatment – that claims seem exaggerated. Yet, experimental evidence has transformed his viewpoint.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, but over 20 years ago, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He designed tools for biological testing,” he says. “I was quite suspicious. It was an unusual wavelength of about 1070 nanometres, that many assumed was biologically inert.”

Its beneficial characteristic, though, was that it travelled through water easily, enabling deeper tissue penetration.

Mitochondrial Effects and Brain Health

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, including the brain,” says Chazot, who prioritized neurological investigations. “Studies demonstrate enhanced cerebral circulation with light treatment, 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, notes the scientist, “activates protective proteins that safeguard mitochondria, look after your cells and also deal with the unwanted proteins.”

All of these mechanisms appear promising for treating a brain disease: antioxidant, anti-inflammatory, and cellular cleanup – autophagy being the process the cell uses to clear unwanted damaging proteins.

Ongoing Study Progress and Specialist Evaluations

Upon examining current studies on light therapy for dementia, he reports, several hundred individuals participated in various investigations, comprising his early research projects