In a Nutshell
Before we discuss the various studies that have been conducted with red light therapy and cancer, here's a brief summary:
- Potential anti-cancer effects: In some contexts, light therapies like PDT have been used to target and treat certain types of cancer cells.
- Increase in tumor size in mice: One study  raised concerns that in certain conditions, 642nm wavelength might promote tumor growth (where cancer cells pre-exist).
- A contradictory study says that red light therapy is safe even when malignant lesions are present .
- Can red light therapy cause cancer? Current research does not indicate that red light therapy causes cancer.
- Is red light therapy safe for cancer patients? There are studies that show cancer reduction and one that shows tumor size growth. There's not enough evidence yet to say RLT is safe for cancer patients and more research is needed.
- Can red light therapy cause cancer cells to grow? Some studies suggest so (more research is needed)
- Can infrared light cause cancer? We did not find any research to substantiate that infrared rays can cause cancer.
- Is there a risk of cancer by using red light therapy? Current research suggests not.
- Given the studies on mice where cancer cells grew, if you are someone recovering from cancer or recently recovered, there is no evidence that light therapy is safe (or unsafe), so please consult your physician before using red light therapy. Note: Studies in mice do not always directly translate to human outcomes.
- If you don't have cancer, currently, no direct link between red light therapy and cancer development has been established, which makes red light therapy safe to use.
- More research is needed to fully understand the various effects of red light therapy on cancer cells and we highly recommend consulting your health practitioner to obtain advise that's right for your circumstances.
In recent years, red or infrared light therapy (RLT) has been getting a lot of attention from the medical community. What has everyone so excited is the ability of this treatment process to have such a positive impact on the treatment of various physical and psychological issues. Among the issues that RLT seems to offer great home benefits are hair replacement, vision correction, skin ailments, and even psychological issues like depression and anxiety.
While it offers great hope that RLT might end up being a super cure of sorts for lots of issues, there is also great hope infrared light therapy can have a material impact on the fight against cancer. For centuries, cancer has been an enemy versus the mortality of the human race. There are treatments available such as surgery, radiation, and chemotherapy, but they are such invasive treatments. The medical community has been looking for a better option that causes less damage. They may have found it with RLT.
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The Science Behind Red Light Therapy
To help you understand how RLT could be useful in the battle against cancer, some scientific knowledge about the red light therapy process could be useful.
Each human cell is filled with organelles called mitochondria. Mitochondria is an energy source for cell growth and regeneration. When cells get damaged or die, they cause a lot of physical or even psychological issues for the individual as the mitochondria lie dormant. However, the energy from infrared light has proven to be the perfect energy boost for mitochondria.
This is how the magic works. When the infrared light hits the mitochondria, the light brings the mitochondria to life. That immediately results in damaged cells getting repairs and new cells being generated. Cell reparation and growth are the keys to the health benefits that seem to follow.
Based on this knowledge, you can probably begin to anticipate how the RLT process would work with cancer. Of course, there are three issues at hand. First, could RLT play a role in killing off cancer cells? Second, to what degree could RLT help replace dead cancer cells with healthy growing cells? Finally, would RLT not cause cancer cells to grow?
Let us investigate.
Can red light therapy help treat cancer?
To answer this question, we have to relate back to the two questions brought up in the above section. First, does RLT have a way to contribute to the killing of cancer cells? According to researchers, including Dr. Hisataka Kobayashi at the NIH’s National Cancer Institute (NCI) , the answer to this question appears to be yes.
According to their work, researchers found that by employing monoclonal antibody (mAb) therapy in mice, they could release antibodies that would attach to cancer cells. They discovered that when these antibodies are hit with infrared light, the cancer cells started dying immediately. This process has been successful through much testing on test subjects (animals) with tumors of various types and sizes.
Note: The appropriate red or light therapy wave frequency for treating most cancers would appear to be in the low-800s nm and mid-600s nm ranges. At these wave frequencies, the light should be able to penetrate the skin and the soft tissue of the organs. The irradiance of the device should be at least 100mw/cm squared for the light to be able to penetrate deep enough to be effective.
If RLT can assist in the killing of cancer cells, there is already evidence that the process will wake up cellular mitochondria, prompting the growth of new cells and the reparation of damaged cells in the same areas. As the RLT ignites the immune system to new levels, there is a lot of healing that should take place.
Now, the concern shifts to whether RLT will cause cancer cells to grow and repair.
Can you get cancer from red light therapy?
At this point, there is no evidence a person can get cancer from RLT. A great research piece  summarising light therapy and cancer research, states that patients receiving red light therapy had statistically better progression free survival than those in the placebo group.
However, there is evidence from one study  that shows RLT could cause existing tumors and cancer cells to grow. From what has already been described as the science behind RLT, we know the process works to incite cell growth. Remember, cancer cells are simply human cells that have mutated into cancer cells. They do have mitochondria as an energy source for growth.
At issue would seem to be wave frequency. At higher levels, say 850 nm or higher, there is a good chance tumors will grow. This makes RLT for cancer a bit of a balancing act. Before this process can be used on humans, there needs to be more information related to the risk/reward and possible side effects of this process.
Is red light therapy safe for cancer patients?
There is no clear answer to this issue at this time. As we stated above, there is a possibility RLT could spur cancer cell growth. There needs to be a lot more research on this issue before anyone can give a definitive answer to this question. That research will need to be done on human subjects. Some of the appropriate clinical trials are underway .
Red light therapy for various types of cancer
As RLT gains respect as a possible treatment for cancer, the medical community will want to start focusing on what types of cancer will apply to this process. As of now, there is evidence that indicates all types of cancer may be subject to RLTs effectiveness or growth. Let us take a quick look at four of the most common forms of cancer and the likelihood RLT is a possible solution.
As a soft tissue cancer close to the surface, the RLT process is showing positive results with breast cancer.
There are issues related to the treatment of brain cancer with RLT. It would seem to have something to do with skull penetration levels. At safe wave frequencies at around 600nm to 700 nm, the ability of infrared light to penetrate the skull is limited. The solution would be using higher wave frequencies, which would result in a little more risk. However, the risk could be worth it given the serious nature of brain cancer.
Since infrared light penetration is always a key consideration, skin cancer is likely the easiest form of cancer to treat with RLT. In fact, the treatment of skin cancer with RLT is proving to have a very high degree of success.
Much like breast cancer, the RLT process is showing positive results with lung cancer as another soft tissue endeavor.
Red light therapy vs photodynamic therapy for cancer
This particular comparison has to be made with a certain degree of conjecture. Based on testing information, red light therapy appears to help kill cancer cells without causing further damage to skin and organs. With photodynamic therapy, there is possible residual damage from the treatment process.
Also, there is a possibility using RLT therapy could result in the promotion of cancer cell growth. That is not a possibility with photodynamic therapy.
Does red light therapy cause skin cancer?
Again, there is no evidence that red light therapy causes cancer. However, there could be an issue with this process promoting and growth and spreading of existing tumors or cancer cells.
Does red light therapy prevent skin cancer?
To reiterate, there is strong evidence that red light therapy in conjunction with the right antibodies could help prevent skin cancer. Without the addition of the right antibodies, RLT might have the opposite effect and actually ignite cancer cell growth.
Red Light Therapy Devices
Until the FDA authorizes the use of infrared light therapy to treat cancer, the subject of devices is sitting on the backburner. It is not clear if people will be able to manage the RLT process at home or have to depend on clinics.
If the time comes when RLT for cancer is approved and authorized at home, patients will be happy to learn there is a growing population of quality devices that people might be able to use for cancer treatment in a home environment. It still remains to be seen.
 nih.gov - Targeted Light Therapy Destroys Cancer Cells (opens in a new tab)
 Study: Increase in tumor size in mice (opens in a new tab)
 cancer.gov - Photoimmunotherapy (opens in a new tab)
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5946726/ (opens in a new tab)
 Study - Red Light Therapy safe when malignant lesions are present (opens in a new tab)