7 Little-Known Side Effects of Daylight Saving Time

Your body may never adjust to losing an hour of sleep. Degtiarova Viktoriia/Shutterstock

Every November, people curl up in their warm beds thanking their lucky stars for that extra hour of sleep. The spring, however, is another story. In March, daylight saving time isn't quite so popular, pulling people from their beds an hour early.

The case against daylight saving time goes far beyond the mild inconvenience many feel in spring. It turns out, there is a ton of data that points to the negative effects the change in time has on our bodies. In addition, its energy-saving benefits have been hotly debated.

1. Our bodies may never adjust to the new time

A group of German researchers believes that our bodies never actually adjust to daylight saving time, and that artificially altering our circadian rhythm can be damaging for our health.

Lead researcher, Till Roenneberg of Ludwig-Maximilians-University, explained, "When you change clocks to daylight saving time, you don't change anything related to sun time. This is one of those human arrogances — that we can do whatever we want as long as we are disciplined. We forget that there is a biological clock that is as old as living organisms, a clock that cannot be fooled. The pure social change of time cannot fool the clock."

They found that the body had no trouble adjusting to the ending of daylight saving time in the fall (when we gain an hour), but it never quite makes the adjustment to the change in the spring (when we lose an hour).

2. The time change reduces the duration and 'efficiency' of sleep

A 2006 study out of Finland monitored the sleep patterns of people for 10 days surrounding the transition to daylight saving time. They found that the resulting decrease in sleep by about one hour reduced a person’s sleep efficiency by 10%. The study concluded that the time change appears to compromise a person’s sleep by decreasing the number of hours he or she slept as well as overall sleep efficiency.

3. It could result in more heart attacks

Illustration of a heart with a clock inside and the lines of a cardiogram
Changes on the clock aren't the best for your ticker. cyrrpit/Shutterstock

Scientists looked at the data from patients in Michigan hospitals from 2010 to 2013. They found that on the Monday after daylight saving time went into effect, there were 25% more heart attacks than on a standard Monday. What’s really strange is, that didn’t make the total number of heart attacks for the month go up. Lead author, Dr. Amneet Sandhu, explained, "What's interesting is that the total number of heart attacks didn't change the week after daylight saving time. But these events were much more frequent the Monday after the spring time change and then tapered off over the other days of the week. It may mean that people who are already vulnerable to heart disease may be at greater risk right after sudden time changes."

Another study that took place in Sweden found that the chance of suffering from a heart attack increases during the first three weekdays after the March daylight saving shift.

Both scientists reached the same conclusion. That, based on the findings, those who are at higher risk of heart issues may do better not to have their normal sleep cycles disrupted.

4. Increase suicide risk for vulnerable individuals

A study published in Sleep and Biological Rhythms found that, for individuals with bipolar disorder, large disruptions in sleep patterns can be severe, and potentially even deadly. Researchers looked at Australian suicides from 1971 to 2001 to see if the time change had any impact on the number of recorded suicides. The results conclude that male suicide rates do indeed increase in the weeks following daylight saving time when compared to the return to eastern standard time and the rest of the year.

5. Increase in workplace injuries

A study published in the Journal of Applied Psychology looked at workplace injuries in the periods directly after the time changes associated with daylight saving time. They found that, on the Monday after an hour of sleep is lost, workers were more frequently injured and those injuries were more serious in nature. On the fall days that we gain an hour, the researchers found that there were no significant differences in the number of injuries sustained or the severity.

6. Lower SAT scores?

A clock next to a standardized testing sheet
It's bad enough standardized tests are timed, but daylight saving time seems to have an influence on test-taking performance. Have a nice day Photo/Shutterstock

This one might only matter if you’re in high school, although one could start speculating about what the time change does to our minds based on this study. The study authors wrote, "Controlling for socioeconomic status by proxy, the principal finding was a surprisingly strong negative relationship between imposition of the time policy in a geographic area and SAT scores of local high school students. The cautious conclusion is that the daylight-saving time policy should possibly be even more controversial for, at minimum, its economic implications."

7. When we're tired, we cyberloaf

A study published in the Journal of Applied Psychology found a link between daylight saving time and increased cyberloafing behaviors. What is cyberloafing? Basically, messing around on the internet by checking social media, personal email or doing anything other than the jobs we’re being paid to do during work hours. The researchers say that the study demonstrates that there is a "dramatic increase in cyberloafing" during the spring time shift. The study doesn’t pin it all on the time change. A general lack of sleep seemed to trend towards increased searches for cats being annoyed by dogs, and things of the like.

With all the data out there, many question whether daylight saving time is necessary, and if it’s doing more harm than good. Either way, for the moment, it’s here to stay, so, after you change your clocks, take the opportunity to catch up on some chores and, of course, make sure you, and your kids if you have them, get enough sleep.