Exposure to light at night raises cardiovascular disease risk by up to 50 percent over sleeping in the dark, new research shows. However, this risk isn’t from lack of sleep, but from disruption of the body’s master biological clock, the circadian rhythm.

From Andrew J.K. Phillips, Sean W. Cain (Flinders University) and colleagues, co-first authors Daniel P. Windred (Flinders University) and Angus C. Burns (Harvard). Read more in the Harvard Gazette.