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Does Red Light Therapy Cause Cancer?

Does Red Light Therapy Cause Cancer?

Mar 13, 2025 | Sampada Sharma | 13min. reads

Does red light therapy increase cancer risk? Explore the myths from facts and uncover what science says about its safety and health effects. 

Red light therapy (RLT) has gained popularity for its benefits in skincare, pain management, and even hair growth. However, a common concern arises: can red light therapy cause cancer? With increasing exposure to light-based treatments, many wonder whether prolonged or frequent use can pose risks, particularly regarding cancer development. This article aims to address these concerns by exploring the myth behind red light therapy cancer risks, debunking them and presenting scientific evidence regarding its safety.

Key Takeaways: 

  • Red light therapy does not emit ionising radiation and is not linked to cancer risk.

  • Scientific studies show that red light therapy is safe and may even support healing.

  • FDA-approved red light therapy devices follow strict safety regulations.

  • Consult a healthcare provider if you have a history of cancer before using red light therapy.

 

Understanding How Red Light Therapy Works

When assessing whether RLT does cause cancer or not, it is important to understand how this therapy works. RLT uses low-level wavelengths of red or near-infrared light (typically between 600-1000 nm) to penetrate the skin and allow cellular repair and regeneration to take place. Unlike ultraviolet (UV) radiation, known to cause skin damage and consequently increase the risk of skin cancer, it works fundamentally differently when it comes to the risk of cancer in the cells themselves. 

When red light reaches the cells, mitochondria absorb the energy and enhance ATP production. This increased energy fuels cellular repair reduces inflammation, and supports tissue regeneration. Notably, RLT does not employ ionising radiation, which is a form of radiation linked to cancer development. Rather, it stimulates biological healing processes, making it a non-invasive and safe type of therapy for various conditions. 

Debunking the Cancer Concern: Myths vs. Facts

The increasing popularity of red light therapy (RLT) has brought with it a fair share of questions and, unfortunately, some unfounded fears. Among the most persistent concerns is the idea that red light therapy might contribute to cancer development. This issue arises from a mix-up of light therapies with other harmful forms of radiation, such as ultraviolet light. The purpose of this section is to dispel the myth surrounding RLT and cancer; it will further, using clear factual discussion, offer an understanding of the therapy's safety profile. 

Myth 1: Red Light Therapy Emits Harmful Radiation

Fact: Many assume that all forms of light therapy, including RLT, emit harmful radiation. However, does red light therapy cause skin cancer? The answer is no. Unlike UV light or X-rays, RLT does not emit ionising radiation, which is responsible for DNA damage and cancer mutations. Ionising radiation has enough energy to remove electrons from atoms and molecules, thereby altering their structure and potentially leading to cancerous changes. RLT solely uses wavelengths that promote cellular function without altering DNA structure.

Red light, typically in the range of 630-700 nanometers, and near-infrared light, ranging from 800-1000 nanometers, are used in RLT. These wavelengths are absorbed by mitochondria within cells, enhancing energy production in the form of ATP (adenosine triphosphate). This increased energy production supports cellular repair, reduces inflammation, and improves overall cellular function. Because it operates outside the range of harmful UV radiation, RLT is considered a safe and non-invasive therapeutic modality.

Myth 2: LED Lights Used in Red Light Therapy Are Unsafe

Fact: Some people question do LED lights cause cancer? The LED lights used in red light therapy operate at safe energy levels that do not emit heat or UV radiation, eliminating the risk of skin damage or cancer. Concerns about whether LED lights cause cancer are largely based on misconceptions, as these lights are not linked to any known carcinogenic effects.

LEDs (light-emitting diodes) are designed to emit light at specific wavelengths and intensities without producing significant heat or harmful radiation. They are energy-efficient and have a long lifespan, making them suitable for therapeutic applications like RLT. The concerns often arise due to generalisations about all forms of light, failing to differentiate between LEDs used in medical or cosmetic applications and those used in industrial settings where more powerful, potentially harmful light might be produced. However, clinically-approved RLT devices utilise LEDs that have been rigorously tested to ensure they operate within safe parameters.

Myth 3: Red Light Therapy Can Cause Cancer Cells to Grow

Fact: A major concern is can red light therapy cause cancer cells to grow. While red light therapy stimulates cellular activity, there is no scientific evidence supporting claims that it accelerates cancer cell proliferation. In fact, some studies suggest that red light therapy may support immune function and assist in the management of side effects from cancer treatments rather than worsening the condition.

The idea that RLT could fuel cancer growth is largely speculative. Cancer cells, like healthy cells, may respond to the enhanced energy production and stimulation by RLT, but this does not automatically lead to accelerated growth. Some pre-clinical studies suggest that RLT might even exert inhibitory effects on certain cancer cells. For example, RLT has been shown to induce apoptosis (programmed cell death) in some cancer cell lines in vitro. Additionally, by reducing inflammation and improving circulation, RLT can create an environment that is less conducive to cancer progression.

Facts


Scientific Evidence on Red Light Therapy and Cancer

To date, numerous studies have examined the safety profile of red light therapy. Research indicates that red light therapy and cancer concerns are largely unfounded. For example, a study published in the Photomedicine and Laser Surgery journal found that RLT does not promote abnormal cell growth or tumour development. Instead, it helps with tissue healing and reducing inflammation in patients undergoing radiation therapy.

In a different study published in the journal Lasers in Medical Science, RLT was investigated for its effect on skin cancer cells. The study showed that RLT did not promote growth in melanoma cells and, in some cases, affected their growth in the opposite direction. That is to say, this research suggests that the effect of RLT can be cell-type specific and should never be generalised as a universal promoter of cell proliferation.

Additionally, research on red light therapy cancer risk shows that low-level light therapy (LLLT) may have potential benefits for cancer patients rather than posing risks. Some studies even suggest that RLT can help manage symptoms in cancer patients, such as pain relief and tissue recovery after chemotherapy or radiation treatment. Chemotherapy and radiation often cause significant damage to healthy tissues, leading to side effects like mucositis (inflammation of the mucous membranes) and dermatitis. RLT enhances healing and decreases the severity of these side effects, improving cancer patients' quality of life.

Regulatory Standards and Certifications

Some regulatory agencies have come up with safety standards, given the increasing popularity of red light therapy. The best red light therapy to reduce cancer risk would have FDA-cleared devices and conform to medical safety standards. 

The red light therapy devices were evaluated in terms of safety and effectiveness by organisations such as the FDA and the American Society for Laser Medicine and Surgery. Properly made devices meet strict regulations to ensure that they do not emit harmful radiation and increase their cancer risk. FDA clearance means the device was reviewed and determined to be safe and effective for its intended use. 

Safety Tips for Using Red Light Therapy

The following tips will help potential red light therapy users optimise the benefits: 

  • Choose FDA-Approved Devices: Ensure that the red light therapy device has good safety ratings and is based on scientific research. Make sure a device has undergone rigorous testing and has been cleared by regulatory agencies.

  • Use as Directed: If any light therapy is overdosed, the skin may become irritated. Therefore, it is essential to follow the guidelines regarding session duration and frequency. Keeping well within the recommended exposure times prevents possible adverse effects and complements the therapeutic effects most fully.

  • Avoid Direct Use on Unhealed Surgical Wounds or Active Skin Infections: Red light therapy promotes healing but shouldn't be used on unhealed surgical wounds or untreated infections unless a physician is supervising. Applying RLT could potentially make things worse by worsening the inflammation or interfering with the body's healing process.

  • Consult Your Healthcare Provider: If you are undergoing treatment for cancer or have a history of skin cancer, it is best always to discuss light therapy with a physician to ensure the therapy scope fits in with your general medical condition. They can evaluate your individual risk factors and provide individualised recommendations. 

 

Conclusion

Despite concerns regarding whether red light therapy causes cancer, current scientific evidence does not support the claim that it contributes to cancer development. Unlike UV rays or other forms of harmful radiation, red light therapy cancer risk remains negligible due to its non-ionizing nature. On the contrary, some studies even suggest it may be beneficial for cancer patients by aiding in symptom relief and recovery.

As long as the red light therapy devices are properly regulated and safety guidelines are followed, red light therapy is safe to use for cancer patients. Advances in research and light therapy promise an expanded further involvement of light in health and wellness. 

 

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