Despite alarmist headlines and a study that suggested morning people live longer, the truth is more complicated, reports The New York Times.
Last spring, a study set the internet ablaze with sensational headlines promising an early death for those with nontraditional sleep schedules. It wasn’t the conclusion of the study, or its researchers. But in the bombastic world of science reporting, it didn’t really matter. Originally published in the journal Chronobiology International, the study looked at the chronotypes — a means of classifying one’s predisposition for sleeping at certain hours — of more than 430,000 people over a six-and-a-half-year period. Scouring data from the National Health Service in England and the NHS Central Register in Scotland, researchers sought to find out what, if any, negative health impacts awaited those with a night-owl schedule.
More than 10,000 participants died during the study period. Of those deaths, the bulk seemed to be the result of natural causes. The study didn’t necessarily seek to link death with sleep deprivation, but rather to “comorbidity” — the occurrence in one person of two or more conditions, such as psychological or neurological disorders, diabetes and the like. With each incremental shift toward a night-owl schedule, comorbidities became more common, increasing the risk of an early death. But while saying that night owls are going to die early makes for an eye-catching headline, the real story isn’t quite that simple.
It’s evident that owls’ nontraditional schedules put them at risk of significant health problems. Nearly every study on this chronotype has returned troubling findings. But Kristen Knutson, the lead author of the Chronobiology International study, warned against drawing conclusions based on simple correlation. Dr. Knutson, an associate professor at Northwestern University who studies neurology and sleep medicine, told The Los Angeles Times that issues arise for night owls who try to live in a morning lark world, staying up late while adding to their sleep debt each morning.