Skin cancer is the most prevalent type of cancer in the United States and throughout the world. While there are many potential causes, ultraviolet (UV) light is by far the most common cause. “The two main causes of skin cancer are the sun’s harmful ultraviolet (UV) rays and the use of UV tanning machines,” says the Skin Cancer Foundation.
Although red light is not UV light, being cautious is understandable, especially for those with a history of cancer. Research has shown, however, that red light is non-carcinogenic. So in response to the question, “can red light therapy cause skin cancer?” the answer is no. We’ll explain why in this article, but first, let’s examine what red light therapy is and how it works.
A Red Light Primer
Red light therapy, which is also called photobiomodulation (or low-level light therapy (LLLT), works in accordance with the scientific fact that various wavelengths of light have different effects on the body. These effects vary based on color; the visible spectrum of light, including blue, green, amber, and red wavelengths, have the most significant benefits and do not harm the human body.
Scientific research conducted over the past two decades has shown that the most significant health benefits occur within the red and near-infrared (NIR) wavelengths.
These wavelengths are measured in nanometers (nm), with red wavelengths ranging in size from 630nm to 660nm, and NIR wavelengths ranging from 800nm to 850nm.
Not all of the visible and invisible energy that emanates from the sun is perceived as “light” by humans. Far-infrared wavelengths, for example, are invisible to the human eye but are perceived as heat, which can cause tissue damage.
Ultraviolet waves are also invisible to the human eye, but we can see their effects on the skin as tans and sunburns, as well as age spots and wrinkles.
Healing at the Cellular Level
When the red light is shone on the skin, light photons absorb into tissue and are soaked up by mitochondria, which are the “energy factories” within cells. This interaction stimulates mitochondria to produce more cellular fuel, which energizes cells and leads to an incredible ripple effect of beneficial biological processes.
When mitochondria are low on energy, they can’t function properly. Conversely, when energy production increases, cells perform at their best. This leads to improved functioning of systems and organs, with benefits that include faster muscle recovery, reduced inflammation, improved lymphatic flow, faster wound healing, and improved nervous system functioning, among a host of others.
What Science Says About Red Light and Cancer
Because red light stimulates cell growth, and cancer is caused by cells growing out of control, this has created some concern about whether red light can promote tumor growth. As the authors of a 2012 study write: “LLLT has been increasingly used for numerous conditions, but its use in cancer patients … has been withheld by practitioners because of the fear that LLLT might result in initiation or promotion of metastatic lesions or new primary tumors.”
The study, conducted by researchers from the University of Rochester, sought to answer the question of whether red light therapy was safe for people suffering from cancer. Twice a day, researchers exposed mice with UV-induced skin cancer to red light, while a control group of mice received no treatment.
After 37 days, there was no measurable growth on the red-light-treated tumors; in fact, there was a small reduction in tumor size in that group. This suggests that red light therapy stimulates the growth of healthy cells, but not malignant growths. From their findings, the researchers concluded that red light does not contribute to tumor growth, and there is no reason it should be withheld from cancer patients.
Why Does UV Light Therapy Cause Cancer and Red Light Doesn’t?
Although ultraviolet light is known to be carcinogenic, it is used (with extreme caution) to treat chronic skin conditions such as psoriasis, vitiligo, and severe cases of eczema. UV phototherapy to treat psoriasis, for instance, involves repeated exposure to UV wavelengths alone or in combination with medications.
According to a 2017 publication by Germany’s Institute for Quality and Efficiency in Health, long-term UV light therapy can increase the risk of melanoma. This is particularly true when using UVA light in combination with a medication called psoralen, which makes the skin more responsive to UVA light, thereby increasing its effectiveness.
The risk associated with UV light therapy goes up even more if a patient has a fair complexion, has had skin cancer in the past, and/or takes immunosuppressants.
Narrowband UVB phototherapy, which refers to a specific wavelength of UV radiation, may carry a lower risk, but there are too few studies for that to be conclusive.
Why Red Light Stimulates Only Healthy Cell Growth
During the 2012 University of Rochester study, the researchers delved into why red light, which is known for stimulating cell growth, does not also stimulate the growth of cancerous cells. They hypothesized that the answer may lie in the systemic effects of red light phototherapy.
For example, one protective effect was the thickening of the epidermis or outermost layer of skin. By the second day of red light therapy, the skin of the treated mice became lighter in color, as well as glossier (more reflective), and less transparent than the skin of the control mice. This suggested that the skin was healing from previously induced UV damage, and also becoming thicker and more resistant to further UV damage.
Another observed effect was that LLLT-treated mice exhibited normal feeding, drinking, and grooming behavior. This was in stark contrast to symptoms of sickness exhibited by the control mice, such as lack of movement, lack of grooming, and shivering. This suggests that LLLT boosted the immune systems of treated mice; and that a more robust immune system may naturally prevent tumors from spreading.
From all that they observed during the study, the researchers concluded that by stimulating the body’s natural healing processes, the body is better able to naturally fight malignant tumor growth.
In the published study, they also point out another important consideration: which tissues are reached by the light, and which molecules known as chromophores are absorbing the light. If light can penetrate deeply enough to stimulate lymphatic vessels, internal organs, and bone marrow, this could result in a faster and more effective immune response that helps prevent cancer growth, even if existing tumors also absorb the red light photons.
In fact, LLLT could potentially become a valuable oncology therapy, both as a complementary treatment to ease the effects of chemotherapy and radiation; and, possibly as a cancer treatment in its own right.
Photodynamic Therapy for Cancer
The three most common types of cancer therapy are surgery, chemotherapy, and radiation. These treatment methods are effective at destroying cancer cells, but also cause significant damage and death to healthy tissue. One emerging option with significantly fewer side effects is photodynamic therapy or PDT.
Photodynamic therapy is a two-stage treatment Research suggests that PDT may be as effective as surgery or radiation. A 2004 clinical trial of 101 cancer patients studied the effects of PDT on basal cell carcinoma, which is the most common form of skin cancer and is linked to excessive sun exposure. PDT was given twice to 52 of the patients, one week apart, and the remaining 49 patients underwent surgery.
The trial showed that 83 percent of the PDT patients were tumor-free after three months, compared with 96 percent of the surgery patients. The researchers concluded that PDT is an effective treatment for basal cell carcinoma.
Photodynamic therapy is currently in clinical trials in patients with inoperable tumors. According to the National Cancer Institute, these trials include patients with metastatic breast cancer, advanced pancreatic cancer, advanced lung cancer, and head and neck cancer.
Red Light Therapy For Skin Cancer: Is It Safe?
Research has clearly shown that light therapy is safe and can be beneficial for people with cancer. Hundreds of studies have shown virtually no side effects and no harmful effects.
In fact, at least one expert says it can be part of your oncology treatment. In a December 2016 editorial published in the Journal of Biophotonics, Harvard Medical School professor and world-renowned expert on red light therapy, Michael R. Hamblin states that photobiomodulation “can be used to mitigate the side-effects of cancer therapy (radiotherapy and/or chemotherapy).
Ways Red Light Can Support Cancer Treatment
As Dr. Hamblin explained, red light therapy can lessen the severity of side-effects associated with chemotherapy and radiation. This is especially helpful in cases where side-effects are so severe that the patient cannot or won’t continue with the treatment.
Research strongly supports the use of red light as therapy for common side effects of cancer treatment. Here are some examples:
- Peripheral neuropathy, which is the loss of sensation in the hands and feet, is one of the side-effects of chemotherapy. In a 2016 study, 70 cancer patients who were suffering from peripheral neuropathy were divided into two groups: one whose participants were treated with red light therapy, and the other whose participants received “sham-treatment,” meaning they formed the control group.
- Over a period of six weeks, the red light therapy group received three weekly treatments of 30 minutes each. At the conclusion of the study, the red light group saw a significant reduction in neuropathy symptoms compared with the control group.
- A common side-effect of radiation treatment is radiation dermatitis, which is burned damage to skin that is often painful. A 2016 study of breast cancer patients who suffered from radiation dermatitis revealed statistically better skin assessments after treatment with LLLT.
- Another common side-effect of radiation therapy is moist desquamation, a condition in which the skin thins and then “weeps” due to damage to the epithelial barrier. A 2018 study of 120 breast cancer patients showed that the incidence of moist desquamation was significantly reduced in the patients treated with red light therapy.
- Lymphedema, or swelling in the arms and/or legs, affects roughly 30 percent of post-surgery breast cancer patients. Studies have shown that LLLT reduces inflammation that can interfere with lymphatic capillaries’ ability to drain lymph from the area. It also increases the rate of lymph node pumping and regeneration of lymph vessels.
- A 2017 study followed patients with oropharynx, nasopharynx, and hypopharynx (head and neck) cancer. Researchers found that patients receiving LLLT had a significantly better complete response to treatment compared with the placebo group, including progression-free survival and better overall survival.
- Hair loss is an expected but often traumatic side-effect of cancer treatment. Chemotherapy targets fast-growing cancer cells but also affect other cells of the body, including those of the skin and hair follicles. As a result, skin and hair problems are quick to develop after starting chemotherapy. We can use LLLT for hair loss as it stimulates hair follicles to produce more energy, which results in these cells replicating more successfully. This results in new hair growth from previously-dormant follicles.
- A 2017 study involved women who had undergone chemotherapy for breast cancer. They were randomly assigned to either an LLLT group or a placebo group. The women in the LLLT group were treated with PBM, and the others were treated with a device that was identical in appearance but contained only incandescent lights. The patients used these devices at home for 25 minutes every other day. After 24 weeks, patients in the LLLT group demonstrated a significant increase in hair regrowth compared with the control group.
Red light therapy may also be used as a pre-and post-surgery treatment to accelerate healing by boosting the immune system. In a 2016 study, a team of researchers from Italy used both red (660nm) and near-infrared (800 and 970nm) light once a day on mice with melanoma and oral cancer. The researchers found that the mice given red light therapy had an increased immune response and faster healing.
Red light: Safe and Beneficial
Low-level laser therapy can play an important role in mitigating and relieving the side effects of cancer therapy. It can also promote good health, without the worry of stimulating the growth of any existing cancer cells or the growth of new cancers.
With thousands of studies proving its efficacy with virtually no side effects, red light may be a viable treatment whether you’re cancer-free, battling the disease, or in remission.
Again, please consult your doctor if you have the concern that “can red light therapy cause skin cancer” and especially if you’re taking photosensitizing medications.
One last point we want to make: A huge benefit of red light therapy is that you can self-administer it in the comfort of your own home.
Frequently Asked Questions
Q. Does Red Light Stimulate Collagen?
Ans: Yes, studies show that Red light therapy help to build new collagen and protect the existing collagen in your skin.
Q. How long does it take to recover from photodynamic therapy?
Ans: Usually, photodynamic therapy takes approximately 2 to 6 weeks to heal the area completely, but it varies on how big the area is and which body part has been treated.