natural light-dark cycle
Posted on by Dr. Francis Collins
School’s starting soon, and a lot of kids (and some adults) who were sleeping late this summer are struggling to reset their sleep cycles. All summer, those biological clocks have been getting pushed back. Artificial light allows us to work and play into the wee hours, interfering with the natural light-dark cycle that, over most of human history, began at sunrise and ended just after sunset.
But there’s a price to be paid for this modern shifting of biological clocks: research shows that long term indulgence in these late sleep schedules leads to unwanted weight gain and obesity, mood problems, substance abuse, and, of course, morning sleepiness. Light and sleep are critical to good health—and that’s one reason NIH funded a team at the University of Colorado Boulder to investigate the impact of natural light on our modern sleep patterns .