It was an arresting image: Four children, wearing black masks to protect their eyes, sitting in front of large lamps. The caption placed them at London’s Institute of Ray Therapy, which opened in 1930.
The old photo got us thinking about light therapy, then and now. A hundred years ago, it was all the rage; in addition to the Institute of Ray Therapy, London also boasted a Municipal Sunlight Clinic. The concept seems to be coming back in vogue now; celebrities from Jennifer Aniston to Lady Gaga have been touting the benefits of sweating it out under infrared lights in a steamy sauna.
A little digging through old medical journals (and, yes, modern search engines) turned up an array of therapies based on artificial light. Here, some of our favorites uses for the humble lamp:
Strengthening fragile bones
Beginning in the late 1800s, it wasn’t unusual to go to a hospital and see small groups of children and babies, wearing little more than protective goggles, sitting around under or in front of what was essentially a giant sunlamp. The ultraviolet light was meant to treat a condition called rickets, which causes the bones to soften. In the most severe cases, children with rickets develop bowed legs. The condition is caused by a severe vitamin D deficiency; doctors thought high doses of ultraviolet light would help by spurring the children’s bodies to synthesize vitamin D. And there’s some anecdotal evidence that it did make a difference.
The treatment became less common after 1932, when the U.S. began adding vitamin D to milk. Doctors also realized that it actually doesn’t take much sun to get enough vitamin D, as long as there’s some skin exposure.
Smoothing blemished skin
Doctors have long used forms of near-infrared, ultraviolet, and laser therapy to treat skin conditions. It’s an easy sell to patients who feel disfigured by conditions like cystic acne, psoriasis, eczema, vitiligo, and skin lesions. To this day, light therapy is marketed as an outpatient treatment for many dermatological woes.
Somewhere along the way, though, marketers got the idea that they could sell light as having broader beautifying effects. Beauty Angel, a company based in Germany, boasts that standing inside one of its infrared light machines makes you pretty by building up collagen, reducing fine lines, and softening the skin. Small studies have found some improvements in the skin appearance of healthy patients exposed to various light therapies (including LED lights and infrared diode treatment).
But when celebrities claim that relaxing in an infrared sauna can rejuvenate cells and flush out toxins, they’re way overselling the science.
Improving mental health
It’s debatable whether light therapy can make you look good, but studies show that it can make you feel good — or better, anyway. Recent studies provide evidence that light therapy can improve symptoms of depression in college students, pregnant women, and other adults. A 2016 study found that even among patients already taking antidepressants, those who added bright light to their regimen found more relief.
There’s now a whole market for “light therapy” boxes to treat seasonal affective disorder (depression that surfaces in the low-light seasons of fall and winter). They sell for anywhere from $25 to $300.