Daylight Saving Time Change Toughest on Night Owls

MONDAY, July 26, 2021 (HealthDay News) -- If you struggle with the spring time change, your genes may be to blame, researchers report.

They found that people whose genes make them more likely to be early birds adapt to the time change in a few days, while night owls could take more than a week to return to their normal sleep schedule after clocks "spring forward' one hour.

The study included more than 800 first-year medical residents taking part in the Intern Health Study based at the Michigan Neuroscience Institute.

Early birds had adjusted their sleep times by the Tuesday after the weekend change to daylight saving time, but night owls were still off track by the following Saturday.

The findings, published July 20 in the journal Scientific Reports, add to arguments to do away with daylight saving time, said study senior author Margit Burmeister, a neuroscientist and geneticist at the University of Michigan.

"It's already known that DST has effects on rates of heart attacks, motor vehicle accidents and other incidents, but what we know about these impacts mostly comes from looking for associations in large data pools after the fact," she said in university news release.

"These data from direct monitoring and genetic testing allows us to directly see the effect and to see the differences between people with different circadian rhythm tendencies that are influenced by both genes and environment. To put it plainly, daylight saving time makes everything worse for no good reason," Burmeister added.

"This study is a demonstration of how we much we vary in our response to even relatively minor challenges to our daily routines, like daylight saving time," said study co-author Dr. Srijan Sen, who leads the Intern Health Study.

"Discovering the mechanisms underlying this variation can help us understand our individual strengths and vulnerabilities better," he said in the release.

Like all interns, those in the study were generally chronically sleep-deprived because of the number of hours they need to be on duty or preparing for duty, which made them an interesting group to study, according to the researchers.

More information

There's more on daylight saving time at the American Academy of Sleep Medicine.

SOURCE: University of Michigan, news release, July 20, 2021