Daylight Saving Time has long-term effects on health

https://www.eurekalert.org/pub_releases/2019-11/vumc-dst110419.php

News Release 4-Nov-2019
Vanderbilt University Medical Center

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, DST eliminates bright morning light that critically synchronizes biologic clocks, which can be associated with increased risk of heart attack and ischemic stroke, as well as other negative effects of partial sleep deprivation.

Average sleep duration shrinks by 15 to 20 minutes for adults during DST transitions, which may also increase the risk of fatal accidents.

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"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 said.

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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. State legislation is "all over the map," with some states considering a return to standard time and others in favor of permanent DST. Tennessee has passed legislation supporting permanent DST, although such a change would require action from the U.S. Congress.