New research has shown how, over time, Day Light Savings can have negative impacts on health – increasing the risk of heart attacks and strokes.
The annual transition to and from daylight saving time (DST) has clinical implications that last longer than the days where clocks ‘fall back’ or ’spring forward.’.
Over time, Daylight Saving Time eliminates bright morning light that critically synchronises biological clocks, which can be associated with increased risk of heart attack and ischaemic stroke, as well as other negative effects of partial sleep deprivation.
Decreasing sleep, increasing risk
Average sleep duration shrinks by 15 to 20 minutes for adults during Daylight Saving Time transitions, which may also increase the risk of fatal accidents.
Beth Ann Malow, MD, Burry Chair in Cognitive Childhood Development, and professor of Neurology and Paediatrics in the Sleep Disorders Division at Vanderbilt University Medical Center, said: “People think the one-hour transition is no big deal, that they can get over this in a day, but what they don’t realise is their biological clock is out of sync.”
“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 Daylight Saving Time 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 said.
Malow and colleagues published a JAMA Neurology commentary recapping large epidemiological studies that advocate for ending the practice of setting clocks forward or back.
Some people may have more flexible circadian rhythms and adjust quickly while others are more sensitive. Malow, an expert on autism and sleep, said that the transition impacts some children with autism for weeks or months.
While the sleep and circadian communities believe returning to standard time may be more biologically appropriate, gaining political buy-in for a nationwide change remains a challenge.
In March, the European Union voted to end Day Light Savings in 2021. Clock would be adjusted on the final Sunday of March 2021 or the final Sunday of October 2021 depending on whether it is preferred to stay in summer or wintertime.