CNN —
The end of daylight saving time is upon us again, a fall tradition when the United States, Europe, most of Canada and a number of other countries move their clocks back an hour in a kind of Groundhog Day observance . We will promote them (again) next spring when governments bring back daylight savings time.
But do we trust an unhealthy, outdated idea?
Not according to the United States Senate, which in March passed the Sunshine Protection Act of 2021 — if it becomes law, daylight saving time will be permanent.
“The call to end the antiquated practice of changing the clocks is gaining momentum across the nation,” Sen. Marco Rubio (R-FL), who first introduced the bill in the US Senate, said in a statement. The Florida Legislature voted to make daylight saving time permanent in Florida in 2018, but it cannot take effect until federal law is implemented.
The bill still needs to pass the US House of Representatives and be signed into law by the President. If or when that happens, we’ll move our clocks forward and leave them at that, permanently living an hour ahead of the sun.
But a growing number of sleep experts say that moving our clocks forward in the spring is wreaking havoc on our health. Studies over the past 25 years have shown that the one-hour change disrupts the body’s rhythms that are tuned to the Earth’s rotation, adding fuel to the debate over whether daylight saving time in any form is a good idea.
“I’m one of the many sleep experts who know it’s a bad idea,” said Dr. Elizabeth Klerman, a professor of neurology in the division of sleep medicine at Harvard Medical School.
“Your body clock stays with (natural) light not the clock on your wall,” Klerman said. “And there’s no evidence that your body completely shifts to the new age.”
Dr. Phyllis Zee, director of the Center for Circadian and Sleep Medicine at Northwestern University Feinberg School of Medicine in Evanston, Illinois, also opposes DST.
“Between March and November your body gets less morning light and more evening light, which can throw off your circadian rhythm,” she said.
Standard time, which we enter when we move our clocks back in the fall, is much closer to the sun’s day-night cycle, Zee said. This cycle has set our circadian rhythm, or body clock, for centuries.
This internal timer controls not only when you sleep, but also when you want to eat, exercise or work, as well as “your blood pressure, your heart rate and your cortisol rate,” Zee added.
A call for a permanent DST ban came from the American Academy of Sleep Medicine: “Current evidence best supports adoption of year-round standard time, which better aligns with human circadian biology and provides distinct public health and safety benefits . ”
The proposal has been endorsed by more than 20 medical, scientific and policy organizations, including the American College of Occupational and Environmental Medicine, the National Parent Teacher Association, the National Safety Council, the Society for Research on Biological Rhythms and the World Sleep Society.
When our internal clocks are shifted from the solar day-night cycle by even an hour, we develop what sleep experts call “social jet lag.” Studies have shown that social jet lag increases the risk of metabolic disorders such as diabetes, increases the risk of heart disease and stroke, worsens mood disorders such as depression, affects the digestive and endocrine systems, and reduces the duration of our sleep. It can even reduce life expectancy,
A 2003 study found that sleeping one hour less for two weeks had the same effect on thinking and motor skills as going without sleep for two whole nights. Cutting sleep by 90 minutes from the recommended 7 to 8 hours for adults changed the DNA of immune system cells and boosted inflammation, a key cause of chronic disease, according to another study.
Permanently changing the time would make the chronic effects of any sleep loss more severe, not only because we have to go to work an hour earlier for an extra 5 months each year, but also because body clocks are typically slower in the winter than summer. with reference to the sundial,” according to a statement from the Society for Research on Biological Rhythms.
“The combination of daylight saving time and winter time would make the differences between the body clocks and the social clock even worse and negatively affect our health even more,” the authors concluded.
There are reasons why the US Senate unanimously passed the Sun Protection Act. Proponents say the extra daylight in the evening reduces traffic accidents and crime and increases opportunities for commerce and recreation, as people prefer to shop and exercise during the day.
However, research has shown that both heart attacks and fatal traffic accidents increase after the clock falls in the spring. Children also end up going to school in the morning while it is still dark – with disastrous consequences.
When President Richard Nixon signed permanent daylight saving time into law in January 1974, it was a popular move. But by the end of the month, Florida’s governor had called for the law to be repealed after eight students were hit by cars in the dark. Schools across the country delayed their start time until the sun rose.
By summer, public approval had plummeted, and in early October Congress voted to return to standard time.
A similar reaction occurred when the US first implemented daylight saving time in 1918 as a way to reduce demand for electricity use by adding sunlight at the end of the day in response to World War I. savings from practice.) The timer was so unpopular that the law was repealed the following year.
“The United States has tried permanent daylight saving time twice before and ended it early. The UK tried once before and ended it early. Russia tried it once, so did India and it ended early,” Klerman said. “I think we should learn from history.”
