🔗 Share this article

Light therapy is clearly enjoying a surge in popularity. There are now available glowing gadgets designed to address dermatological concerns and fine lines as well as aching tissues and gum disease, recently introduced is a toothbrush outfitted with miniature red light sources, described by its makers as “a significant discovery for domestic dental hygiene.” 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 thermal energy targets your tissues immediately. According to its devotees, it feels similar to a full-body light therapy session, boosting skin collagen, soothing sore muscles, alleviating inflammatory responses and long-term ailments and potentially guarding against cognitive decline.

Understanding the Evidence

“It sounds a bit like witchcraft,” notes a neuroscience expert, professor in neuroscience at Durham University and a convert to the value of light therapy. Naturally, some of light’s effects on our bodies are well established. Sunlight enables vitamin D production, needed for bone health, immunity, muscles and more. Sunlight regulates our circadian rhythms, additionally, stimulating neurotransmitter and hormone production during daytime, and winding down bodily functions for sleep as it fades into night. Artificial sun lamps are standard treatment for winter mood disorders to elevate spirits during colder months. 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 rigorous scientific studies, like examinations of infrared influence on cerebral tissue, identifying the optimal wavelength is crucial. Light constitutes electromagnetic energy, spanning from low-energy radio waves to the highest-energy (gamma waves). Light-based treatment uses wavelengths around the middle of this spectrum, the highest energy of those being invisible ultraviolet, then visible light (all the colours we see in a rainbow) and infrared light visible through night vision technology.

Dermatologists have utilized UV therapy for extensive periods to manage persistent skin disorders including eczema and psoriasis. It affects cellular immune responses, “and reduces inflammatory processes,” explains 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) “typically have shallower penetration.”

Safety Considerations and Medical Oversight

The side-effects of UVB exposure, like erythema or pigmentation, are understood but clinical devices employ restricted wavelength ranges – signifying focused frequency bands – which minimises the risks. “Treatment is monitored by medical staff, thus exposure is controlled,” says Ho. Essentially, the light sources are adjusted by technical experts, “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.”

Home Devices and Scientific Uncertainty

Colored light diodes, he explains, “aren’t really used in the medical sense, but they may help with certain conditions.” Red wavelength therapy, proponents claim, help boost blood circulation, oxygen uptake and skin cell regeneration, and promote collagen synthesis – a primary objective in youth preservation. “The evidence is there,” comments the expert. “However, it’s limited.” Nevertheless, with numerous products on the market, “we don’t know whether or not the lights emitted are reflective of the research that has been done. Optimal treatment times are unknown, proper positioning requirements, whether or not that will increase the risk versus the benefit. Many uncertainties remain.”

Specific Applications and Professional Perspectives

Initial blue-light devices addressed acne bacteria, microorganisms connected to breakouts. 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, 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, standards are somewhat unclear.”

Innovative Investigations and Molecular Effects

At the same time, in advanced research areas, scientists have been studying cerebral tissue, identifying a number of ways in which infrared can boost cellular health. “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. Yet, experimental evidence has transformed his viewpoint.

The researcher primarily focuses on pharmaceutical solutions for brain disorders, though twenty years earlier, a doctor developing photonic antiviral treatment consulted his scientific background. “He designed tools for biological testing,” he explains. “I was pretty sceptical. It was an unusual wavelength of about 1070 nanometres, which most thought had no biological effect.”

Its beneficial characteristic, nevertheless, was its efficient water penetration, meaning it could penetrate the body more deeply.

Cellular Energy and Neurological Benefits

More evidence was emerging at the time that infrared light targeted the mitochondria in cells. Mitochondria are the powerhouses of cells, producing fuel for biological processes. “Every cell in your body has mitochondria, including the brain,” notes the researcher, who concentrated on cerebral applications. “Research confirms improved brain blood flow with phototherapy, which is consistently beneficial.”

With specific frequency application, mitochondria also produce a small amount of a molecule known as reactive oxygen species. In limited quantities these molecules, says Chazot, “activates protective proteins that safeguard mitochondria, protect cellular integrity and manage defective proteins.”

These processes show potential for neurological conditions: oxidative protection, swelling control, and cellular cleanup – autophagy representing cellular waste disposal.

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, incorporating his preliminary American studies