What is Red Light Therapy?

The History of Red Light Therapy

People have used light as a therapy since the beginning of time. Ancient Egypt, India, and Greece erected temples for healing light therapies. In medieval times, Florence Nightingale, who, in the 1850s, advocated the use of clean air and an abundance of sunlight to restore health, began the modern renaissance in ‘light as therapy.’ 

It was not until much later, in 1962, that Nick Holonyak invented and demonstrated the first semiconductor laser diode that emitted visible red light while working at General Electric.

That same year, Endre Mester at the Semmelweis Medical University in Hungary tried to replicate an experiment performed by Paul McGuff of Boston, who had used a high-powered ruby laser to cure malignant tumors in rats. Much to Mester’s discovery, he inadvertently made a much lower-powered laser, and the tumors that had been implanted into the rats were not affected by his low-powered laser, and it seemed the experiment had failed. But before closing the research book on this failed attempt he did observe something very interesting. He observed that where he had shaved and implanted the tumors in the rats and applied his lower-powered laser the rate of healing of the incisions and the hair growth was much faster than normal. This was the first discovery that low-level laser light could have its own beneficial applications in medicine.

Though this was a great discovery on the part of Endre Mester, many did not believe this low-level laser therapy produced any real therapeutic benefits to the body. It was not until 1989 that Tiina Karu wrote a paper that was instrumental in understanding how this low-level laser therapy, also known as red light therapy and photobiomodulation, worked. She discovered that the therapy works through the mitochondria. When shining red light therapy on the tissue, the cytochrome c oxidase enzyme in the mitochondria absorbs this light, and the various mechanisms that cascade afterward to the organisms are astounding. The brain gets more blood flow, our cells get more energy, genes and stem cells activate left and right.

In 1995, NASA funded Quantum Devices Inc. to complete an LED plant-growth unit that grew potatoes on the space shuttle. Once in space, astronauts who spent time working with their hands under these LED lights found that abrasions on their hands healed much faster. NASA then brought the technology back down from space and started researching its biological effects on humans. Combining Tiina's research and NASA's continued studies with human candidates and the therapy's validity, this is how the industry of red light therapy emerged. There are now thousands of studies on the effects of red light therapy on the various mechanisms of the human body.