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Phototherapy is certainly having a surge in popularity. You can now buy glowing gadgets targeting issues like complexion problems and aging signs to muscle pain and gum disease, the newest innovation is a dental hygiene device outfitted with tiny red LEDs, described by its makers as “a breakthrough for domestic dental hygiene.” Globally, the industry reached $1 billion in 2024 and is forecast to expand to $1.8 billion by 2035. There are even infrared saunas available, which use infrared light to warm the body directly, the infrared radiation heats your body itself. Based on supporter testimonials, the experience resembles using an LED facial mask, enhancing collagen production, soothing sore muscles, alleviating inflammatory responses and long-term ailments and potentially guarding against cognitive decline.

The Science and Skepticism

“It sounds a bit like witchcraft,” observes a neuroscience expert, professor in neuroscience at Durham University and a convert to the value of light therapy. Naturally, we know light influences biological functions. Our bodies produce vitamin D through sun exposure, 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. Daylight-simulating devices are standard treatment for winter mood disorders to boost low mood in winter. Undoubtedly, light plays a vital role in human health.

Types of Light Therapy

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. In serious clinical research, such as Chazot’s investigations into the effects of infrared on brain cells, determining the precise frequency is essential. Photons represent electromagnetic waves, which runs the spectrum from the lowest-energy, longest wavelengths (radio waves) to the highest-energy (gamma waves). Therapeutic light application utilizes intermediate light frequencies, with ultraviolet representing the higher energy invisible light, then visible light (all the colours we see in a rainbow) and then infrared (which we can see with night-vision goggles).

Ultraviolet treatment has been employed by skin specialists for decades to treat chronic skin conditions such as eczema, psoriasis and vitiligo. It works on the immune system within cells, “and suppresses swelling,” explains a dermatology expert. “There’s lots of evidence for phototherapy.” UVA goes deeper into the skin than UVB, while the LEDs in consumer devices (usually producing colored light emissions) “tend to be a bit more superficial.”

Safety Considerations and Medical Oversight

UVB radiation effects, including sunburn or skin darkening, are recognized but medical equipment uses controlled narrow-band delivery – signifying focused frequency bands – which decreases danger. “Therapy is overseen by qualified practitioners, thus exposure is controlled,” notes the specialist. And crucially, the light sources are adjusted by technical experts, “to ensure that the wavelength that’s being delivered is fit for purpose – different from beauty salons, where oversight might be limited, and emission spectra aren’t confirmed.”

Consumer Devices and Evidence Gaps

Colored light diodes, he says, “aren’t typically employed clinically, though they might benefit some issues.” Red wavelength therapy, proponents claim, enhance blood flow, oxygen utilization and cell renewal in the skin, and promote collagen synthesis – a key aspiration in anti-ageing effects. “The evidence is there,” states the dermatologist. “However, it’s limited.” Nevertheless, given the plethora of available tools, “it’s unclear if device outputs match study parameters. Optimal treatment times are unknown, how close the lights should be to the skin, whether or not that will increase the risk versus the benefit. Numerous concerns persist.”

Treatment Areas and Specialist Views

Early blue-light applications focused on skin microbes, bacteria linked to pimples. The evidence for its efficacy isn’t strong enough for it to be routinely prescribed by doctors – although, notes the dermatologist, “it’s commonly used in cosmetic clinics.” Some of his patients use it as part of their routine, he mentions, but if they’re buying a device for home use, “we just tell them to try it carefully and to make sure it has been assessed for safety. If it’s not medically certified, oversight remains ambiguous.”

Cutting-Edge Studies and Biological Processes

At the same time, in a far-flung field of pioneering medical science, scientists have been studying cerebral tissue, discovering multiple mechanisms for infrared’s cellular benefits. “Pretty much everything I did with the light at that particular wavelength was positive and protective,” 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 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 recalls. “I remained doubtful. The specific wavelength measured approximately 1070nm, that many assumed was biologically inert.”

What it did have going for it, nevertheless, was its ability to transmit through aqueous environments, enabling deeper tissue penetration.

Mitochondrial Impact and Cognitive Support

Growing data suggested infrared influenced energy-producing organelles. Mitochondria produce ATP for cell function, producing fuel for biological processes. “Every cell in your body has mitochondria, even within brain tissue,” explains the neuroscientist, who prioritized neurological investigations. “It has been shown that in humans this light therapy increases blood flow into the brain, which is consistently beneficial.”

With specific frequency application, cellular power plants create limited oxidative molecules. In limited quantities these molecules, notes the scientist, “activates protective proteins that safeguard mitochondria, protect cellular integrity and manage defective proteins.”

All of these mechanisms appear promising for treating a brain disease: oxidative protection, swelling control, and cellular cleanup – self-digestion mechanisms eliminating harmful elements.

Present Investigation Status and Expert Assessments

Upon examining current studies on light therapy for dementia, he states, approximately 400 participants enrolled in multiple trials, incorporating his preliminary American studies