Not only is daylight saving time (DST) a burden to many Americans, but scientists are now saying it could have negative long-term consequences on the human brain. Three neurologists at Vanderbilt University are advocating doing away with the practice entirely, asserting it contributes to several severe health complications, including stroke risk.
Wartime demands prompted DST to be introduced in the United States in 1918 to lengthen daylight during the summer months. It was modeled after the European version of DST, which had been implemented in 1916. The practice was abolished as a federal policy shortly after it was introduced due to its unpopularity. It was reinstated as a federal policy in 1942, however, prompted once again by energy crises and war. After the end of the Second World War, it became a local policy that has lived on in most states, though states are allowed to exempt themselves from it, including parts of the state within a different time zone. It has also varied in its implementation, with the United States experimenting with “permanent” DST during the OPEC oil embargo.
There is significant controversy surrounding DST. Proponents claim it saves energy and promotes healthy living by enabling outdoor leisure activity in summer evenings, but opponents note the health risks associated with the practice far outweigh any purported energy savings, which have been deemed inconclusive.
According to a 2017 meta-analysis of 44 studies pertaining to DST energy savings, DST leads to an electricity savings of just .34 percent during DST, mostly as a result of residential lighting. However, research indicates DST actually increases total energy consumption when considering non-electricity sources of energy consumption, including extra heating fuel and extra gasoline. In some cases, DST increases residential electricity consumption as a result of more air conditioner use in the longer summer evenings.
Meanwhile, some say the health risks associated with DST are well-documented and less arguable. These include significant increases of heart attacks and stroke, fatigue, and decreased productivity, increases in headache occurrences, and a rise in depression. Even traffic accidents increase as a result of time shifts, according to research from AAA Colorado.
Neurologists Drs. Beth A. Malow, Olivia J. Veatch, and Kanika Bagai at Vanderbilt University Medical Center in Nashville prepared a study published in JAMA Neurology on Monday that highlights the dangerous impact of DST on the brain. The scientists attribute these effects to DST’s impact on circadian rhythms, the body’s internal body clock that affects its wake and sleep schedule. Their piece provides evidence that the effects on this circadian rhythms are associated with serious health complications such as stroke.
“The rate of ischemic stroke was significantly higher during the first 2 days after DST transition, with women, older age, and malignancy showing increased susceptibility,” the piece read.
During the switch to and from DST, the average adult’s sleep duration shrinks up to 20 minutes, and despite what is commonly believed, the scientists claim this change to the body’s circadian rhythm is not one that can simply be accommodated in a day or two.
“People think the one-hour transition is no big deal, that they can get over this in a day, but what they don’t realize is their biological clock is out of sync,” says Dr. Beth Ann Malow, professor of Neurology and Pediatrics in the Sleep Disorders Division at Vanderbilt University Medical Center, in a release.
The researchers claim the impact on the body’s internal clock is far more long-term.
“It’s not one hour twice a year. It’s a misalignment of our biologic clocks for eight months of the year. When we talk about DST and the relationship to light, we are talking about profound impacts on the biological clock, which is a structure rooted in the brain. It impacts brain functions such as energy levels and alertness,” she adds.
Unfortunately, despite agreement amongst the scientific community that DST is far more dangerous than any benefits to be derived from it, the researchers note it would be difficult to gain enough political support to end the practice nationwide. Business interests have been successful at lobbying politicians to advocate for DST, and lawmakers pay particular attention to local special interests to ensure votes from constituents.
And according to the Washington Post, Democrats are stronger proponents of DST than Republicans.
“This may seem surprising given the business community’s support for DST,” the Postwrites. “But conservatives’ opposition probably stems from a broader aversion to government intrusion into something as fundamental as the time of day.”