In the 1960s, Doctor Endre Mester thought it would be interesting to test the impact of light on a tumor. But by pointing a low-energy laser at the shaved skin of a mouse, this Hungarian doctor unwillingly became a pioneer of phototherapy. He actually found that the red light facilitated hair growth and healing. Sixty years later, the trend of light therapy continues, it even seems to be experiencing a second wind. From specialized clinics to the sofa, the power of the light-emitting diode (LED) is becoming increasingly popular.
Also possible with the cold laser, phototherapy is based on the low intensity of the light emitted, measured in milliwatts per centimeter. Today it is applied using LED masks for the face, or even for the whole body, or even with small portable wands. Its promise: to heal, fend off the effects of aging and even rejuvenate. But are these devices, which sometimes cost four-figure sums, worth their price?
The results of scientific research are promising, recalls National Geographic. In the decades following Endre Mester’s discovery, phototherapy has demonstrated a range of positive effects. Although we don’t know exactly why, blue light can, for example, treat acne and relieve other skin problems, such as reducing inflammation.
As for red and near-infrared light, their broader wavelengths can target skin cells or penetrate deeper into the body. “This sets off a chain reaction in the mitochondria»indicates Daniel Barolet, researcher in laser dermatology, practitioner and professor at McGill University in Montreal (Canada). A domino effect that stimulates collagen production and blood circulation. On the surface, it also accelerates healing – particularly of burns and ulcers – and reduces signs of aging such as wrinkles and brown spots.
Little-known long-term effects
So how does it work? LED phototherapy, or more specifically photobiomodulation (PBM), uses soft, low-intensity light in the visible spectrum, typically blue, red, or near-infrared, to stimulate natural physiological processes. “We use light to give cells a boost in the right direction”summarizes Daniel Barolet.
It must be said that we are already supposed to receive these benefits through the Sun. For the first time in human history, we now spend more time indoors, away from natural light. A “little boost” can therefore prove useful. The tissues that stand to gain the most from PBM are those that suffer from a state of exhaustion, such as sunburned skin, explains Alexander Wunsch, doctor and phototherapy expert.
Beware of beautiful promises
However, photobiomodulation is far from being able to solve all skin problems. “There is real science behind it and phototherapy works clinicallyexplains Zakia Rahman, professor of dermatology at Stanford University (United States). But it will not have the spectacular effect that other, more profound medical treatments can have.”
LEDs may be painless, but prolonged exposure to blue light (close to the ultraviolet spectrum) can cause skin damage, premature aging or irritation. Quite the opposite of what initial therapy seeks, therefore, not to mention that scientific research on long-term effects remains limited. Red and near-infrared light, on the other hand, carry fewer risks. Only allergies to the Sun and particularly sensitive eyes would be to be feared, according to Daniel Barolet.
When choosing phototherapy at home rather than in a clinic, another risk comes into play: that of poor quality devices. Experts advise looking first and foremost at the intensity of the light power. “There are a lot of scams… Most of the time the energy is very, very low”notes Glynis Ablon, professor of dermatology at the University of California in Los Angeles (United States).
For red light LED masks, Glynis Ablon recommends devices that emit 105 milliwatts per centimeter. In blue light, the intensity may be lower. “If it’s around 40, why not, but if we reach 10, it’s probably useless”she said.
In some cases, photobiomodulation works best when combined with other treatments. “This is the case with the red light and anti-aging cream duo”concludes Daniel Barolet. Phototherapy obviously does not replace other products such as sunscreen or prescription retinoids. Whether you choose the clinic or the LED mask, experts advise not to abandon any other treatment and not to expect immediate results.
