Researchers have discovered a "U-shaped" link between sleep and the biological clocks of 17 different organ systems. Sleeping fewer than 6 hours or more than 8 hours accelerates the aging of your heart, lungs, and immune system. By analyzing data from half a million people, the study identifies a "longevity window" of 6.4 to 7.8 hours, highlighting sleep as a vital, modifiable lifestyle factor for systemic health.
