Scientists from the University of Michigan believe that it might be time to abandon Daylight Saving Time. They have also discovered that DNA profile plays a significant role in how changing the clock affects people. Early birds might need only a few days to adjust to the change, while those considered night owls might need more than a week.

How researchers conducted the study

To come to this conclusion, researchers followed 831 doctors during the first year of their post-medical school training. These participants were part of the Intern Health study in the Michigan Neuroscience Institute. The researchers also calculated the Objective Sleep Midpoint polygenic score, determining if a person is likely to be a night owl or an early riser.

After calculating the scores, the team monitored two groups, each with 130 doctors. One group with high genomic scores were more likely to be night owls, while the group with the low genomic scores were most likely early risers. Researchers then observed them a week before and after the DST and took note of their sleep patterns.

Researchers observed a difference in the time the two groups went to sleep on no-work days. DST affected the time the two groups woke up. Early risers were less affected and would adjust to changes by Tuesday. However, night owls would not adjust until the following Saturday.

The wake-up times on workdays remained the same, probably because interns keep a strict schedule. Their demanding schedules is what made the researchers decide to choose young doctors for the study.

Workers on a regular shift are not affected by DSL

According to Margit Burmeister, a geneticist and neuroscientist, while it is common knowledge that DST impacts car accidents and the rate of heart attacks, this information comes from studying data after the fact. However, this study uses direct monitoring to reach its conclusion 

Researchers found that the sleep cycle of the average person is usually not affected by DSL. However, people working in changing time zones or abnormal shifts like healthcare workers are affected the most.

Burmeister adds that the practice worsens things for shift workers when it has no good reason to be done.