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Medical Research Consultant focusing on Advocacy, Education and Information for Cannabis Reform and Psychedelic Reform. Medical Professional (Retired)

“We’ve #lost the #contrast between #light and #dark, and we are #confusing our #physiology on a regular basis,” said John Hanifin, PhD, associate #director of Thomas Jefferson University’s Light Research Program. Our own #galaxy is #invisible to nearly 80% of #people in North America. In 1994, an earthquake-triggered #blackout in Los Angeles led to calls to the Griffith Observatory from people wondering about that hazy blob of light in the #night #sky. It was the Milky Way. Glaring #headlights, #illuminated buildings, blazing #billboards, and #streetlights fill our #urban #skies with a #glow that even #affects #rural #residents. Inside, since the invention of the light #bulb, we’ve kept our #homes bright at night. Now, we’ve also added #blue light-emitting #devices#smartphones, #television screens, #tablets — which have been linked to #sleep #problems. For one 2024 #study, researchers used #satellite data to #measure light #pollution at #residential #addresses of over 13,000 people. They found that those who lived in #places with the brightest skies at night had a 31% #higher risk of high blood pressure. Another study out of Hong Kong showed a 29% higher risk of #death from #coronary #heart #disease. And yet another found a 17% higher risk of #cerebrovascular disease, such as #strokes or #brain #aneurysms. Of course, urban areas also have #air pollution, noise, and a #lack of #greenery. So, for some studies, #scientists #controlled for these #factors, and the #correlation remained strong (although air pollution with fine #particulate #matter appeared to be worse for heart health than outdoor light). Research has revealed that light at night (#indoors or #out) disrupts #circadian #clocks, increases #inflammation, affects #cell division, and #suppresses #melatonin, the “hormone of darkness.” “Darkness is very important,” Hanifin said. When he and his colleagues #decades ago started studying the effects of light on human #physiology, “people thought we were borderline crazy,” he said. The #hormone #melatonin, produced when it’s #dark by the #pineal gland in the #brain, is a key player in this modern struggle. Melatonin helps you sleep, synchronizes the body’s circadian rhythms, protects #neurons from #damage#regulates the #immunesystem, and fights inflammation. But even a sliver of light at night can #suppress its #secretion. Less than 30 lux of light, about the level of a #pedestrian street at night, can slash melatonin by half. Researchers #concede that #satellite data might be too #coarse to #estimate how much light people are actually #exposed to while they sleep. Plus, many of us are staring at #bright #screens. “But the studies keep coming,” Nelson said, suggesting that outdoor light pollution does have an #impact. https://lnkd.in/gu8DRdWm

Why Scientists Are Linking More Diseases to Light at Night

Why Scientists Are Linking More Diseases to Light at Night

webmd.com

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