Shifting our schedule by one hour twice a year is certainly annoying. It can also be downright dangerous.
In the week after the springtime change, when we move our clocks back and lose an hour of sleep, men with heart disease are at an increased risk for heart attacks, some groups are more likely to have a stroke and there is an increase in deadly car accidents.
But biannual clock change is not the most harmful part of daylight saving, said Dr. Adam Sorscher, the director of sleep health at Alice Peck Day Memorial Hospital in Lebanon, it’s where the dial remains on the clock — either standard time or daylight saving time.
On Tuesday, the U.S Senate unanimously passed legislation that would permanently end the clock changes, plopping the United States in daylight saving time forever. In other words, clocks would forever be an hour forward with more daylight hours later in the day. Proponents of the change argue that leaving more daylight hours later on the clock will let kids play outside for longer and could help lessen seasonal affective disorder.
However, Sorscher and the big players in sleep medicine research say clocks should remain constant on standard time, providing more sunlight in the mornings. Artificially forcing more light hours later in the day could have serious health consequences, they say.
For most humans, preferences for light in the morning and dark in the evening are baked into our biologically determined sleep and wake cycles, Sorscher said.
“When we have more darkness in the morning, it delays the waking up of our circadian rhythm, so we do poorly in the morning,” he said.
Between March and November, when the country follows daylight saving time, daylight suppresses melatonin production and delays the subsequent cascade of reactions that help us sleep, pushing bedtimes later.
The ultimate result is a decline and quantity and quality of sleep for the average American, Sorscher said.
Prolonged sleep deprivation can cause a whole host of health problems, he said.
“This switch to daylight saving time is not really giving us more sun; that’s a fixed reality,” he said. “Any public policy that is going to reduce, on average, the amount of sleep that people get is going to be harmful to health.”
In the short term, less sleep can result in difficulties regulating emotions and lessened productivity. In the long term, sleep deprivation can contribute to obesity, depression and anxiety and a weakened immune system.
Sorscher said the public has misplaced affection toward daylight saving time because it happens to coincide with summer, when there are more hours of sunlight anyway.
“It’s kind of piggybacked onto our favorite time of year and thereby gets this kind of warm, fuzzy response, but it’s especially not good in the winter,” he said.
In the 1970s, the United States piloted year-round daylight saving time but after a few months of cold, dark mornings, pre-sunlight accidents and minimal energy conservation, public outrage forced the experiment to end.
Even if the experiment had continued for several years, Sorscher said Americans would likely never fully adjust to the time shift, he said. There are some people who work the overnight shift for their entire careers and never adapt.
“We adapt some, but we’re also hard-wired in terms of our internal circadian rhythm relative to the patterns of the sun,” he said. “That’s to say, we are diurnal creatures. We do better in the daylight in terms of being active and you can’t get around that.”