Incandescent bulbs are back because LEDs cause health problems. By Tracy Beanz & Michelle Edwards at The Highwire.

Throughout history, humans have lived under two lights. Sun and fire.

The incandescent bulb arrived in the 1800s … Then, about fifteen years ago, we traded that warm light for something our biology had yet to experience: the LED. As is the case with many novelties, no one checked into what it might do to us.

The swap from incandescent to LED bulbs became mandatory, thanks to a 2007 energy bill signed by George W. Bush. … LEDs use about 75% less electricity than incandescent, they last for years, and old bulbs waste most of their energy as heat. Without much thought, the switch looked like pure progress to many.

But then a funny thing happened:

Last month, when the Department of Energy testified to Congress in support of bringing back incandescent bulbs, it caught the attention of those of us against LED….

Light is not just something that we see. Light is biological information, and every cell in our body evolved under the sun and the fire, both of which pour out a full, continuous spectrum that is heavy in warm reds and invisible near-infrared light. The incandescent bulb, for all of its efficiency, is itself a small, tamed fire. They called that waste. But the “wasted” heat that regulators scolded for its infrared radiation is the same frequency that has bathed our bodies for centuries.

Because:

LED light is altogether different, making light through a narrow electronic process that spikes strong in the blue part of the light spectrum, and emits almost no infrared at all. Even worse, it flickers rapidly, switching on and off hundreds of times per second. The flicker is too fast to register with our conscious eye, but it is not too fast to wreak havoc on our nervous system. …

Blue-heavy light from typical LEDs lowers the membrane potential in our mitochondria, thus impacting the electrical charge that lets our mitochondria produce ATP, the energy currency of the cell. Along with that, blue light in the evening suppresses melatonin and disrupts circadian rhythms, which in turn affects sleep, hormone balance, and overnight cellular repair. And studies on animals reveal that blue light causes retinal damage. Eye damage is significant because half of the human brain is wired, either directly or indirectly, to process what it receives through the eyes. Stare too long at a device and, yes, your eyes are wrecked. …

Dr. Jack Kruse … insists that our mitochondria respond directly to the light that hits our skin and eyes, and that the red and near-infrared wavelengths they need are exactly those emitted by incandescent light. The LED light does not have this. … Now, our bodies are starved of them all day under blue-heavy light, leading to exhaustion, shallow sleep, and a dry, dead feeling behind the eyes, with no explanation for where it came from.

Couldn’t be bothered with a full-on science video today. This is breathtakingly short:

ChatGPT:

There is credible evidence for specific applications, including some forms of wound healing, oral mucositis associated with cancer therapy, certain pain and inflammatory conditions, hair growth and aspects of skin treatment. However, study methods and doses vary greatly, and results are not uniformly convincing.

Evidence for broad claims such as extending lifespan, treating systemic mitochondrial dysfunction, preventing dementia or substantially improving general health is not established. Brain photobiomodulation, including 810–1070 nm devices, is biologically plausible and has encouraging early studies, but human trials remain relatively small and exploratory. Animal Alzheimer’s research is considerably stronger than the human evidence.”

I switched to incandescents in my office a couple of months ago. Turns out you can still buy them at Bunnings, as specialty spotlight bulbs (Osram Concentra Spot R63).