Daylight Savings Time is observed by more than 1.5 billion
people worldwide. In the United States, outside of Hawaii and Arizona, citizens
adjust their time by one hour twice per year. They roll their clocks forward in
the spring and back in the fall. A research initiative has found a significant
increase in the volume of acute myocardial infarctions (AMI) in the state of
Michigan the Monday following the Spring time change and a modestly significant
decrease during the fall change.
The study included 42,060 hospital admissions for AMI over
1354 days including the time change study period. On the Monday following the Spring
time change, researchers observed a 24% increase in AMI for that day alone
(p=0.011). The Tuesday following the fall time change observed a 21% decrease
in AMI for that day (p=0.044). However, no significant difference in the total
number of AMIs were observed for the week as a whole following Day Light
Savings.
The hypothesized reason for why this is occurring is the
manipulation of the sleep-wake cycle, specifically the imbalance of the
autonomic nervous system and the associated rise in pro-inflammatory cytokines.
Overall incidence of AMI during the week of the Spring Daylight Savings Time
change remained constant, suggesting that the reduction in sleep during this
period was potentially accelerating AMI events that were likely to occur in
vulnerable patients regardless of the time change.
There has been controversy over the economic efficacy of
Daylight Savings Time. It was implemented to make better use of daylight hours,
thereby decreasing electricity needs. Some experts have suggested the practice be
stopped altogether. Regardless of whether Daylight Savings is efficient
economically, should it be removed based on the evidence presented here? Ethically,
how does government justify the economic benefits of such a practice at the
detriment to the health of its citizens? If the overall weekly rate of acute
myocardial infarctions remains unchanged, is it justifiable to maintain the
practice? Or does the increased rate of AMIs the Monday following the Spring time
change justify a revision of the system?
References
Kotchen, M., & Grant, L.
(2008). Does Daylight Saving Time Save Energy? Evidence from a Natural
Experiment in Indiana. doi:10.3386/w14429
Sandhu,
A., Seth, M., & Gurm, H. S. (2014). Daylight savings time and myocardial
infarction. Open Heart,1(1). doi:10.1136/openhrt-2013-000019
If Daylight Savings Time is simply accelerating AMI events that were likely to occur regardless, then, in my opinion, Daylight Savings is not truly harmful. However, I wonder if the decreased energy consumption factor is actually accurate at this time or whether it is an antiquated claim still being pushed by government officials. According to your cited paper (Kotchen and Grant 2008), it was found that Daylight Savings actually ended up leading to an increase in energy consumption, not a decrease. This finding (if it is corroborated by other studies) removes the economic incentive for maintaining Daylight Savings.
ReplyDeleteThis was a very interesting post. What other variables did the study take a look at? Are they going to conduct more studies? I'm also curious to see how much energy we save as a result of daylight savings. There are some countries that don't partake in daylight savings as well, I would love to find out why they don't. I think a graph depicting how much more emissions would be released if daylight savings didn't exist would be crucial in this debate. What is more important, the lives of individuals suffering from AMI, or the constant stress and pollution we are putting on the Earth?
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