‘It sounds like witchcraft’: can light therapy really give you better skin, cleaner teeth, stronger joints?

Light therapy is clearly enjoying a moment. Consumers can purchase glowing gadgets designed to address skin conditions and wrinkles along with muscle pain and gum disease, the latest being an oral care tool enhanced with miniature red light sources, described by its makers as “a breakthrough in at-home oral care.” Worldwide, 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, that employ light waves rather than traditional heat sources, 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 persistent medical issues while protecting against dementia.

Understanding the Evidence

“It feels almost magical,” 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. Our bodies produce vitamin D through sun exposure, crucial for strong bones, immune defense, and tissue repair. Sunlight regulates our circadian rhythms, as well, triggering the release of neurochemicals and hormones while we are awake, and signaling the body to slow down for nighttime. Sunlight-imitating lamps are a common remedy for people with seasonal affective disorder (Sad) to combat seasonal emotional slumps. Clearly, light energy is essential for optimal functioning.

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 rigorous scientific studies, such as Chazot’s investigations into the effects of infrared on brain cells, finding the right frequency is key. Light constitutes electromagnetic energy, spanning from low-energy radio waves to high-energy gamma radiation. Therapeutic light application utilizes intermediate light frequencies, the highest energy of those being invisible ultraviolet, then the visible spectrum we perceive as colors and finally infrared detectable with special equipment.

Dermatologists have utilized UV therapy for extensive periods for addressing long-term dermatological issues like vitiligo. It modulates intracellular immune mechanisms, “and reduces inflammatory processes,” notes a dermatology expert. “Substantial research supports light therapy.” UVA goes deeper into the skin than UVB, whereas the LEDs we see on consumer light-therapy devices (which generally deliver red, infrared or blue light) “generally affect surface layers.”

Risk Assessment and Professional Supervision

UVB radiation effects, like erythema or pigmentation, are understood but clinical devices employ restricted wavelength ranges – signifying focused frequency bands – that reduces potential hazards. “Treatment is monitored by medical staff, thus exposure is controlled,” notes the specialist. And crucially, the lightbulbs are calibrated by medical technicians, “to ensure that the wavelength that’s being delivered is fit for purpose – different from beauty salons, where it’s a bit unregulated, and we don’t really know what wavelengths are being used.”

Home Devices and Scientific Uncertainty

Red and blue light sources, he notes, “don’t have strong medical applications, but could assist with specific concerns.” Red wavelength therapy, proponents claim, improve circulatory function, oxygen utilization and skin cell regeneration, and activate collagen formation – an important goal for anti-aging. “The evidence is there,” states the dermatologist. “However, it’s limited.” Nevertheless, amid the sea of devices now available, “it’s unclear if device outputs match study parameters. Appropriate exposure periods aren’t established, ideal distance from skin surface, the risk-benefit ratio. There are lots of questions.”

Treatment Areas and Specialist Views

One of the earliest blue-light products targeted Cutibacterium acnes, bacteria linked to pimples. The evidence for its efficacy isn’t strong enough for it to be routinely prescribed by doctors – although, explains the specialist, “it’s frequently employed in beauty centers.” Individuals include it in their skincare practices, he observes, 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. Without proper medical classification, the regulation is a bit grey.”

Advanced Research and Cellular Mechanisms

Simultaneously, in innovative scientific domains, scientists have been studying cerebral tissue, revealing various pathways for light-enhanced cell function. “Nearly every test with precise light frequencies demonstrated advantageous outcomes,” he says. It is partly these many and varied positive effects on cellular health that have driven skepticism about light therapy – that results appear unrealistic. However, scientific investigation has altered his perspective.

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 created some devices so that we could work with them with cells and with fruit flies,” he recalls. “I was pretty sceptical. The specific wavelength measured approximately 1070nm, which most thought had no biological effect.”

Its beneficial characteristic, nevertheless, was its efficient water penetration, allowing substantial bodily penetration.

Mitochondrial Impact and Cognitive Support

More evidence was emerging at the time that infrared light targeted the mitochondria in cells. These organelles generate cellular energy, generating energy for them to function. “All human cells contain mitochondria, particularly in neural cells,” says Chazot, who concentrated on cerebral applications. “Studies demonstrate enhanced cerebral circulation with light treatment, which is generally advantageous.”

With specific frequency application, mitochondria also produce a small amount of a molecule known as reactive oxygen species. In limited quantities these molecules, explains the expert, “activates protective proteins that safeguard mitochondria, preserve cell function and eliminate damaged proteins.”

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

Present Investigation Status and Expert Assessments

Upon examining current studies on light therapy for dementia, he says, several hundred individuals participated in various investigations, incorporating his preliminary American studies