https://www.naturalnews.com/2025-12-10-science-of-sleep-why-quality-trumps-quantity.html
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Sleep is far more than just shutting down for the night—it's an active biological process essential for clearing metabolic waste from the brain. Dr. John Saito, spokesperson for the American Academy of Sleep Medicine, compares restorative sleep to a washing machine cycle: Just as heavily stained clothing requires multiple cycles to clean, the brain needs uninterrupted sleep phases—light, deep and REM—to effectively flush out toxins. When sleep is fragmented or shortened, harmful byproducts like carbon dioxide, urea and lactic acid accumulate, leading to fatigue, cognitive decline and long-term health risks..."