*Article courtesy of Rejuve.AI*
It was all an accident.
In 1967, Hungarian physician Endre Mester was trying to replicate a US experiment in which the recently invented ruby laser was used to destroy cancerous tumors in rats. Dr Mester’s custom-made laser didn’t appear to have any anticancer effect, as it wasn’t powerful enough. Very interestingly, however, it seemed to promote hair growth and wound healing in his rats.1
Just like that, Dr Mester’s serendipitous discovery would give rise to the first application of low-intensity red light therapy.
Over the next two decades, Dr Mester, along with his sons, dedicated his career to this new line of research, studying the clinical potential of red light therapy in 15 biological systems. And in 1971, he started using this innovative therapy to treat patients with non-healing ulcers.2
In the 1990s, another happy accident triggered a new chapter in the history of red light therapy — this time, at NASA. As NASA explored the use of red light to grow plants in space, scientists noticed that their wounds healed faster. They conducted studies on Navy SEALs and found red light therapy to improve the healing of training injuries by 40%.3 Filled with promise, one of the leaders of this research, Dr Harry T Whelan, was then quoted to say:4
“After years of poison (pills) and knives (surgery) in medicine, wouldn’t it be nice to have something gentle, like light, to heal?”
From there, red light therapy grew into a hot topic in biomedical research, with proponents studying more of its clinical use cases and critics highlighting the gaps in evidence.
But, neither could have predicted that their eyes would ever come across the words:
“Red light therapy is that girl.”
That, ladies and gents, is the TikTok effect in full swing. Indeed, TikTok and other social media platforms have taken red light therapy to the mainstream in the last couple of years. Just a few days ago, Riverdale star Lili Pauline Reinhart proclaimed red light therapy her “new best friend” to her six million followers on TikTok.
Yet, for every “Red light therapy is that girl”, there’s an “I think I burned my face”.
It’s clear that red light therapy’s meteoric rise has also led to a wave of misuse and misconceptions, especially when it comes to the research behind it. So, in this article, we aim to cut through the noise and provide a comprehensive yet digestible breakdown of the science of red light therapy.
What exactly is red light therapy?
Red light therapy, a type of what’s known as photobiomodulation in scientific circles, is a non-invasive therapeutic technique that uses low-power light in the red and near-infrared spectrum. The wavelengths used for photobiomodulation range between 600nm and 1 000nm, and the therapy is thought to treat various pathologies and repair tissue.5
The light source for this therapy can be a laser or LED. The application methods are diverse, including masks, wands, panels, full-body booths, and even intravascular applications.6
The therapy works at the cellular level. With relatively long wavelengths, the light is thought to reach the mitochondria – the energy-producing components of our cells. Here, red light interacts with a specific protein in the mitochondria’s energy production pathway, potentially enhancing the production of ATP – the universal energy source for all living cells.7 An increase in ATP provides us with more energy for all the reactions that take place in our bodies.
Additionally, red light therapy is believed to decrease the production of reactive oxygen species in our immune cells.8 These molecules, when produced in excess, can cause significant damage to the DNA and proteins of neighbouring cells.
The state of red light therapy research
When critics voice concerns about the lack of research on red light therapy, it’s not the quantity of studies they question. In fact, red light therapy has been studied for almost 70 medical conditions.9 The concern lies in the type of studies conducted. Many of these studies were performed on animals or isolated human cells, which don’t directly translate into clinical practice.
What’s needed are randomised clinical trials – the gold standard in medical research. As at 2022, over 400 such trials investigating red light therapy were conducted.7 However, many of these trials yielded negative results. Some scientists attribute this to variations in study designs and the parameters of red light therapy application, such as wavelength, intensity, and duration.1
That said, some studies do show positive results for red light therapy across various medical uses. In the following sections, we’ll delve into the medical uses where red light therapy is growing into standard practice, as well as emerging areas of application.
Red light therapy and skin conditions
Given its popularity on TikTok, it’s no surprise that red light therapy has found its greatest success in skincare.
Acne is one area where red light therapy has been extensively studied. A randomised controlled trial involving 107 patients with mild to moderate acne vulgaris found that a combination of blue and red light delivered by fluorescent lamps led to a significant improvement. For inflammatory lesions, this combination even outperformed benzoyl peroxide, a standard acne treatment.10 However, a systematic review of 25 clinical trials calls for more studies, as existing data is limited by short follow-up times and the exclusion of severe acne cases.11
Red light therapy has also shown promise in skin rejuvenation. In one clinical trial, subjects experienced significant improvements in skin complexion, skin feeling, and skin roughness, along with an increase in collagen density.12
Psoriasis, a chronic skin condition, could potentially be managed with red light therapy. A pilot study showed improvement in subjects, suggesting red light therapy as a potential treatment option.13
Burn scars, particularly in children, have also been studied in relation to red light therapy. A randomised controlled study involving 15 children showed significant improvement in the group who underwent red light therapy, with no side effects reported.14
Lastly, case reports have indicated the potential of red light therapy in treating rosacea, a chronic inflammatory skin disease.15
Red light therapy and alopecia
Remember how the first therapeutic effect observed for red light therapy was hair regrowth in Dr Mester’s lab rats? Well, naturally, that makes androgenetic alopecia the most common form of hair loss, another area where red light therapy is being studied.
In a clinical trial involving 41 patients with androgenetic alopecia, 22 received red light therapy. The primary endpoint was the percent increase in hair counts from baseline. The treatment group demonstrated a significant 39% increase in hair count.16
Further supporting the potential of red light therapy in treating alopecia, a meta-analysis of 11 clinical trials reported its effectiveness. The analysis suggested that a low frequency of treatment – less than 60 minutes per week – was more efficacious.17
However, it’s important to note that 9 of the 11 randomised controlled trials included in the meta-analysis were manufacturer-funded. This has led to criticism of red light therapy due to concerns of bias and conflicts of interest, as most of the large studies are funded by businesses.
Red light therapy and inflammatory disease
Inflammation is the body’s natural response to injury or infection – a protective measure that involves immune cells, blood vessels, and molecular mediators. However, when inflammation persists longer than necessary, it can lead to chronic inflammatory diseases.
One such condition is knee osteoarthritis – the most common joint disease. In an uncontrolled trial, 30 participants received red light therapy combined with exercise. The results indicated that red light therapy reduced pain and improved function in knee osteoarthritis.18
Similarly, three randomised controlled trials of moderate quality showed significant improvements in pain for patients with rheumatoid arthritis, another inflammatory disease, following red light therapy treatment.19
Red light therapy has also been studied in the context of oral mucositis – a painful inflammation and ulceration of the mucous membranes lining the digestive tract, and often a side effect of chemotherapy. An uncontrolled trial involving patients with chemotherapy-induced oral mucositis found red light therapy to be effective in reducing oral mucositis scores.20
Red light therapy and eye disorders
As we explore the emerging therapeutic uses of red light therapy, let’s turn our attention to eye-related conditions. Two disorders stand out: short-sightedness in children and age-related macular degeneration.
Short-sightedness, or myopia, is a condition where the eye is longer than normal, causing distant objects to appear blurry. A year-long study found that red light therapy could slightly reduce this length, improving vision in children with myopia.21
Age-related macular degeneration is a condition that affects the central part of the retina, leading to a loss of central vision. It’s a common cause of vision loss in older adults. Encouragingly, both preclinical and clinical studies have shown that red light therapy can be beneficial in treating age-related macular degeneration. This has led to its approval by regulatory bodies like the FDA and EMA for treating intermediate age-related macular degeneration.22
Red light therapy and depression
Depression, a condition resistant to treatment in over a third of patients, is a key area for innovative research, including studies on red light therapy. Theoretically, transcranial red light therapy can penetrate the cerebral cortex, stimulate the mitochondrial respiratory chain, and significantly increase cerebral blood flow.
In a placebo-controlled randomised trial, red light therapy was delivered to the prefrontal cortex of subjects diagnosed with major depressive disorder. Administered twice a week for six weeks, red light therapy was found to be efficacious, although the optimal dose remains undefined.23
Further supporting these findings, a meta-analysis of clinical trials concluded that red light therapy is effective in reducing depression symptoms.24
Red light therapy and ageing
Earlier, we discussed red light therapy for skin rejuvenation. But, in a world that longs for longevity, red light therapy could offer hope against whole-body ageing.
The most compelling evidence lies in brain ageing. Human studies have demonstrated the promising metabolic effects of red light therapy on the brain, improving electrophysiological activity and cognitive functions such as attention, learning, memory, and mood in older individuals.25
While still in the experimental stage, animal models have shown promise for cardiac ageing. Red light therapy treatment mitigated age-associated cardiovascular changes, improved neuromuscular coordination, and even increased longevity in a mouse model. These findings hint at the potential of red light therapy in promoting healthy ageing.26
Before you go
As we conclude, it’s important to remember that the promising results of the red light therapy we’ve discussed were obtained in controlled laboratory and clinical settings.
Before you consider at-home red light therapy – which comes in a myriad of options with varying wavelengths, intensities, and dose durations – keep this in mind.
So if your takeaway from this article is that red light therapy is indeed “that girl”, it’s best to try it out under the supervision of professionals in reputable medical practices.
References:
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21. Zhou, L., Tong, L., Li, Y., Williams, B. T., & Qiu, K. (2023). Photobiomodulation therapy retarded axial length growth in children with myopia: evidence from a 12-month randomized controlled trial evidence. Scientific Reports, 13(1), 3321. https://doi.org/10.1038/s41598-023-30500-7
22. Fantaguzzi, F., Tombolini, B., Servillo, A., Ilaria Zucchiatti, Riccardo Sacconi, Bandello, F., & Querques, G. (2023). Shedding Light on Photobiomodulation Therapy for Age-Related Macular Degeneration: A Narrative Review. Ophthalmology and Therapy, 12(6), 2903–2915. https://doi.org/10.1007/s40123-023-00812-y
23. Iosifescu, D. V., Norton, R. J., Ümit Tural, Mischoulon, D., Collins, K. A., McDonald, E., Luis De Taboada, Foster, S. L., Cusin, C., Yeung, A., Clain, A., Schoenfeld, D., Hamblin, M. R., & Cassano, P. (2022). Very Low-Level Transcranial Photobiomodulation for Major Depressive Disorder. The Journal of Clinical Psychiatry, 83(5). https://doi.org/10.4088/jcp.21m14226
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Graduating with a Bachelor of Pharmacy and Biotechnology with high honors, Hussein leverages his educational background and lifelong passion for storytelling to translate scientific discoveries into captivating narratives. With a track record spanning over six years, Hussein has crafted research-driven content and led awareness campaigns for 25+ clients across the US, Europe, and the MENA region, including industry-leading pharmaceutical company Roche. His professional journey took an epic turn in 2022 when he stumbled upon the longevity field. He felt a deep connection to this field that transcends everything he studied at school and strives to combat the culprit of all chronic diseases: ageing. This connection quickly turned into an obsession as he immersed himself in all sorts of longevity resources. Then, in July 2023, he solidified this new passion when he graduated as the first-ever Healthy Longevity Talent Incubator at the National University of Singapore—becoming one of only 40 participants worldwide selected for the historical program. And his quest for longevity continues! Hussein currently works as a Medical Content Writer for Rejuve.AI, which sits at the cutting edge between longevity science, AI, and blockchain.
- Al Hussein Elwanhttps://www.aestheticappointment.co.za/author/al-hussein-elwan
