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Light therapy is definitely experiencing a wave of attention. You can now buy illuminated devices targeting issues like dermatological concerns and fine lines to muscle pain and gum disease, recently introduced is a toothbrush equipped with small red light diodes, promoted by the creators as “a major advance in at-home oral care.” Internationally, the industry reached $1 billion in 2024 and is forecast to expand to $1.8 billion 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. As claimed by enthusiasts, it feels similar to a full-body light therapy session, boosting skin collagen, relaxing muscles, reducing swelling and persistent medical issues while protecting against dementia.

Research and Reservations

“It appears somewhat mystical,” observes Paul Chazot, professor in neuroscience at Durham University and a convert to the value of light therapy. Naturally, certain impacts of light on human physiology are proven. Our bodies produce vitamin D through sun exposure, essential for skeletal strength, immune function, and muscular health. Natural light synchronizes our biological clocks, as well, stimulating neurotransmitter and hormone production during daytime, and winding down bodily functions for sleep as it fades into night. Daylight-simulating devices are a common remedy for people with seasonal affective disorder (Sad) 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, most other light therapy devices deploy red or infrared light. In serious clinical research, including research on infrared’s impact on neural cells, finding the right frequency is key. Photons represent electromagnetic waves, spanning from low-energy radio waves to high-energy gamma radiation. Therapeutic light application utilizes intermediate light frequencies, with ultraviolet representing the higher energy invisible light, followed by visible light encompassing rainbow colors and then infrared (which we can see with night-vision goggles).

UV light has been used by medical dermatologists for many years to manage persistent skin disorders including eczema and psoriasis. It modulates intracellular immune mechanisms, “and dampens down inflammation,” says Dr Bernard Ho. “There’s lots of evidence for phototherapy.” UVA reaches deeper skin layers compared to UVB, while the LEDs in consumer devices (typically emitting red, infrared or blue wavelengths) “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 – meaning smaller wavelengths – which minimises the risks. “It’s supervised by a healthcare professional, thus exposure is controlled,” says Ho. Essentially, the devices are tuned by qualified personnel, “to guarantee appropriate wavelength emission – unlike in tanning salons, where it’s a bit unregulated, and wavelength accuracy isn’t verified.”

Commercial Products and Research Limitations

Red and blue light sources, he explains, “aren’t really used in the medical sense, but they may help with certain conditions.” Red light devices, some suggest, improve circulatory function, oxygen absorption and cell renewal in the skin, and stimulate collagen production – a key aspiration in anti-ageing effects. “Studies are available,” states the dermatologist. “However, it’s limited.” 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. Appropriate exposure periods aren’t established, proper positioning requirements, if benefits outweigh potential risks. There are lots of questions.”

Treatment Areas and Specialist Views

Early blue-light applications focused on skin microbes, bacteria linked to pimples. Scientific backing remains inadequate for regular prescription – despite the fact that, notes the dermatologist, “it’s often seen in medical spas or aesthetics practices.” Some of his patients use it as part of their routine, he mentions, though when purchasing home devices, “we just tell them to try it carefully and to make sure it has been assessed for safety. Unless it’s a medical device, the regulation is a bit grey.”

Innovative Investigations and Molecular Effects

Simultaneously, in advanced research areas, Chazot has been experimenting with brain cells, identifying a number of ways in which infrared can boost cellular health. “Pretty much everything I did with the light at that particular wavelength was positive and protective,” he says. It is partly these many and varied positive effects on cellular health that have driven skepticism about light therapy – that claims seem exaggerated. However, scientific investigation has altered his perspective.

Chazot mostly works on developing drug treatments for neurodegenerative diseases, though twenty years earlier, a GP who was developing an antiviral light treatment for cold sores sought his expertise as a biologist. “He developed equipment for cellular and insect experiments,” he recalls. “I was quite suspicious. This particular frequency was around 1070 nanometers, that nobody believed did anything biological.”

The advantage it possessed, nevertheless, was its ability to transmit through aqueous environments, meaning it could penetrate the body more deeply.

Cellular Energy and Neurological Benefits

Growing data suggested infrared influenced energy-producing organelles. Mitochondria produce ATP for cell function, generating energy for them to function. “Mitochondria exist throughout the body, 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 always very good.”

With specific frequency application, cellular power plants create limited oxidative molecules. In low doses this substance, notes the scientist, “triggers guardian proteins that maintain organelle health, protect cellular integrity and manage defective proteins.”

Such mechanisms indicate hope for cognitive disorders: antioxidant, anti-inflammatory, and cellular cleanup – autophagy being the process the cell uses to clear unwanted damaging proteins.

Present Investigation Status and Expert Assessments

The last time Chazot checked the literature on using the 1070 wavelength on human dementia patients, he states, approximately 400 participants enrolled in multiple trials, comprising his early research projects