Humans evolved under red and infrared light from the sun and fire, but standard LEDs emit mostly blue light with almost no infrared. Researchers warn this spectral deprivation causes health problems Khan calls "21st-century scurvy." Get morning sunlight and switch to warmer bulbs at night.
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A brand new 2026 report just showed us what the LED bulbs in almost every home are doing to our bodies. As humans, we evolved being exposed to red and near-infrared light constantly. Inside your cells, your mitochondria have to move electrons to make energy, and there's growing evidence that near-infrared light supports that entire process. Now look at what we used to sit in. Sunlight is full of it. Fire is full of it. Even the old incandescent bulb was put out almost the same shape of spectrum. As the sun— warm, heavy in red and infrared. Then look at the standard LED— a huge spike in blue and effectively zero infrared. And we swapped every indoor space on Earth over to it about 20 years ago. The researchers are literally calling it ultra-processed light— same idea as ultra-processed food, stripped of everything that made the original work. One of the leading researchers in the field calls this deprivation 21st-century scurvy. But the fix costs nothing. Get outside in the morning and again in the late afternoon, even through clouds because the infrared still comes through, and use warmer bulbs at night instead of bright white.