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Light therapy is definitely experiencing a surge in popularity. There are now available illuminated devices targeting issues like skin conditions and wrinkles along with sore muscles and oral inflammation, the latest being a dental hygiene device enhanced with tiny red LEDs, described by its makers as “a major advance in at-home oral care.” Worldwide, the market was worth $1bn in 2024 and is projected to grow to $1.8bn by 2035. You can even go and sit in an infrared sauna, 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, stimulating skin elasticity, easing muscle tension, reducing swelling and long-term ailments and potentially guarding against cognitive decline.

Research and Reservations

“It sounds a bit like witchcraft,” observes Paul Chazot, professor in neuroscience at Durham University and a convert to the value of light therapy. Of course, some of light’s effects on our bodies are well established. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Natural light synchronizes our biological clocks, as well, activating brain chemicals and hormonal responses in daylight, and preparing the body for rest as darkness falls. Artificial sun lamps are standard treatment for winter mood disorders to boost low mood in winter. So there’s no doubt we need light energy to function well.

Various Phototherapy Approaches

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 rigorous scientific studies, 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. Phototherapy, or light therapy uses wavelengths around the middle of this spectrum, with ultraviolet representing the higher energy invisible light, followed by visible light encompassing rainbow colors and finally infrared detectable with special equipment.

Ultraviolet treatment has been employed by skin specialists for decades to treat chronic skin conditions such as eczema, psoriasis and vitiligo. It modulates intracellular immune mechanisms, “and reduces inflammatory processes,” notes Dr Bernard Ho. “Substantial research supports light therapy.” UVA reaches deeper skin layers compared to UVB, in contrast to LEDs in commercial products (which generally deliver red, infrared or blue light) “generally affect surface layers.”

Safety Considerations and Medical Oversight

The side-effects of UVB exposure, like erythema or pigmentation, are well known but in medical devices the light is delivered in a “narrow-band” form – meaning smaller wavelengths – that reduces potential hazards. “Therapy is overseen by qualified practitioners, thus exposure is controlled,” explains the dermatologist. Essentially, the lightbulbs are calibrated by medical technicians, “to confirm suitable light frequency output – unlike in tanning salons, where it’s a bit unregulated, and we don’t really know what wavelengths are being used.”

Commercial Products and Research Limitations

Colored light diodes, he says, “aren’t typically employed clinically, but they may help with certain conditions.” Red light devices, some suggest, improve circulatory function, oxygen absorption and skin cell regeneration, and promote collagen synthesis – a primary objective in youth preservation. “The evidence is there,” says Ho. “Although it’s not strong.” Nevertheless, 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. We don’t know the duration, ideal distance from skin surface, the risk-benefit ratio. There are lots of questions.”

Specific Applications and Professional Perspectives

One of the earliest blue-light products targeted Cutibacterium acnes, microorganisms connected to breakouts. Research support isn’t sufficient for standard medical recommendation – even though, explains the specialist, “it’s frequently employed in beauty centers.” Individuals include it in their skincare practices, he mentions, but if they’re buying a device for home use, “we recommend careful testing and security confirmation. Unless it’s a medical device, standards are somewhat unclear.”

Innovative Investigations and Molecular Effects

At the same time, in innovative scientific domains, Chazot has been experimenting with brain cells, identifying a number of ways in which infrared can boost cellular health. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he reports. The numerous reported benefits have generated doubt regarding phototherapy – that it’s too good to be true. But his research has thoroughly changed his mind in that respect.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, however two decades past, a doctor developing photonic antiviral treatment consulted his scientific background. “He designed tools for biological testing,” he says. “I remained doubtful. The specific wavelength measured approximately 1070nm, that many assumed was biologically inert.”

What it did have going for it, nevertheless, was that it travelled through water easily, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

Additional research indicated infrared affected cellular mitochondria. Mitochondria produce ATP for cell function, producing fuel for biological processes. “Mitochondria exist throughout the body, even within brain tissue,” says Chazot, who prioritized neurological investigations. “Studies demonstrate enhanced cerebral circulation with light treatment, which is consistently beneficial.”

With specific frequency application, energy organelles generate minimal reactive oxygen compounds. In limited quantities these molecules, notes the scientist, “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, anti-inflammatory, and pro-autophagy – 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 states, about 400 people were taking part in four studies, including his own initial clinical trials in the US