If one lives in a country where daylight saving time (DST) is observed, one will be familiar with the biannual shift that body clocks must undergo. Coping with the change is harder for some. According to a new study, the number of days it takes to adapt could be down to one genetic.
Researchers found in a study of around 830 people that people who went to bed early weren’t as badly affected by DST compared to people who slept late. How one understands the workings of circadian rhythm, the findings could have important implications. Circadian rhythm is a natural process that tells when it is time to go to sleep and when to get up again, and this process is important for health.
According to Srijan Sen neuroscientists from the University of Michigan, “This study is a demonstration of how much we vary in our response to even relatively minor challenges to our daily routines, like DST. Discovering the mechanisms underlying this variation can help us understand our individual strengths and vulnerabilities better.”
At a medical school from a sample of 831 interns, genetic DNA profiling and a measure called the Objective Sleep Midpoint polygenic score were used by the researchers to sift out the main study candidates: the 134 individuals most genetically predisposed to be late sleepers and the 133 individuals most genetically predisposed to be early sleepers.
The team used wearables during the DST change in spring in the US to track the response of these interns. On weekdays all the volunteers continued to get up at similar times; there was a significant lack of compatibility when they went to bed, and on weekends going to bed and getting up time.
People who slept early had adjusted to the new timings by Tuesday after the DST shift on Sunday morning. People who slept late were still struggling to come to terms with the change in time by the following Saturday. DST does more harm than good for the researchers; it is more evident.
The researcher team also looked at the DST shift back an hour, which happens in the fall in the US. There are no significant differences in how people who slept early and people who slept early suggested that the bodies find it easier to cope with that particular change.