🔗 Share this article

Light therapy is certainly having a moment. Consumers can purchase glowing gadgets targeting issues like complexion problems and aging signs to muscle pain and periodontal issues, recently introduced is an oral care tool enhanced with small red light diodes, marketed by the company as “a major advance 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, where instead of hot coals (real or electric) heating the air, the infrared radiation heats your body itself. Based on supporter testimonials, it’s like bathing in one of those LED-lit beauty masks, enhancing collagen production, easing muscle tension, reducing swelling and long-term ailments and potentially guarding against cognitive decline.

The Science and Skepticism

“It feels almost magical,” notes Paul Chazot, a scientist who has studied phototherapy extensively. Of course, some of light’s effects on our bodies are well established. Sunlight helps us make vitamin D, essential for skeletal strength, immune function, and muscular health. Sunlight regulates our circadian rhythms, too, stimulating neurotransmitter and hormone production during daytime, and preparing the body for rest as darkness falls. 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

Whereas seasonal affective disorder devices typically employ blue-range light, the majority of phototherapy tools use red or near-infrared wavelengths. During advanced medical investigations, including research on infrared’s impact on neural cells, identifying the optimal wavelength is crucial. Photons represent electromagnetic waves, extending from long-wavelength radiation to short-wavelength gamma rays. Light-based treatment utilizes intermediate light frequencies, including invisible ultraviolet radiation, followed by visible light encompassing rainbow colors and finally infrared detectable with special equipment.

Dermatologists have utilized UV therapy for extensive periods to manage persistent skin disorders including eczema and psoriasis. It modulates intracellular immune mechanisms, “and reduces inflammatory processes,” notes 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) “generally affect surface layers.”

Safety Considerations and Medical Oversight

The side-effects of UVB exposure, such as burning or tanning, are recognized but medical equipment uses controlled narrow-band delivery – signifying focused frequency bands – which minimises the risks. “It’s supervised by a healthcare professional, meaning intensity is regulated,” notes the specialist. Essentially, 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 oversight might be limited, and wavelength accuracy isn’t verified.”

Consumer Devices and Evidence Gaps

Red and blue LEDs, he says, “aren’t really used in the medical sense, but could assist with specific concerns.” Red wavelength therapy, proponents claim, improve circulatory function, oxygen utilization and cell renewal in the skin, and activate collagen formation – an important goal for anti-aging. “Studies are available,” says Ho. “Although it’s not strong.” Regardless, amid the sea of devices now available, “we don’t know whether or not the lights emitted are reflective of the research that has been done. Optimal treatment times are unknown, ideal distance from skin surface, the risk-benefit ratio. Numerous concerns persist.”

Specific Applications and Professional Perspectives

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 – although, says Ho, “it’s frequently employed in beauty centers.” Certain patients incorporate it into their regimen, he observes, though when purchasing home devices, “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

Meanwhile, in innovative scientific domains, researchers have been testing neural cells, revealing various pathways for light-enhanced cell function. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he states. It is partly these many and varied positive effects on cellular health that have driven skepticism about light therapy – that results appear unrealistic. But his research has thoroughly changed his mind in that respect.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, but over 20 years ago, a doctor developing photonic antiviral treatment consulted his scientific background. “He created some devices so that we could work with them with cells and with fruit flies,” he says. “I was quite suspicious. The specific wavelength measured approximately 1070nm, which most thought had no biological effect.”

The advantage it possessed, nevertheless, was that it travelled through water easily, enabling deeper tissue penetration.

Mitochondrial Effects and Brain Health

Additional research indicated infrared affected cellular mitochondria. These organelles generate cellular energy, producing fuel for biological processes. “Mitochondria exist throughout the body, including the brain,” notes the researcher, who concentrated on cerebral applications. “Research confirms improved brain blood flow with phototherapy, which is generally advantageous.”

With 1070 treatment, cellular power plants create limited oxidative molecules. In limited quantities these molecules, says Chazot, “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: oxidative protection, swelling control, and waste removal – autophagy representing cellular waste disposal.

Present Investigation Status and Expert Assessments

Upon examining current studies on light therapy for dementia, he says, several hundred individuals participated in various investigations, including his own initial clinical trials in the US