Ending Clock Changes Could Prevent 300,000 Strokes Annually

A new study from Stanford University suggests that eliminating the switch between daylight saving and standard time could prevent up to 300,000 strokes and 2.6 million cases of obesity each year in the United States.

Researchers compared three time options — permanent standard time (winter), permanent daylight saving time, and the current twice-yearly clock change. The study found that permanent standard time offers the greatest health benefits, aligning best with the body’s natural circadian rhythms.

“Our bodies function best when synchronized with the sunrise,” said Dr. Jamie Zeitzer, professor of psychiatry and senior author of the study published in the Proceedings of the National Academy of Sciences. Morning light promotes alertness, while evening darkness triggers melatonin production and prepares the body for sleep.

The study estimated that maintaining permanent standard time could reduce obesity by 0.78% and stroke incidence by 0.09%, potentially saving millions of lives.

Medical experts warn that frequent disruptions to sleep cycles harm health, increasing fatigue, mistakes, and even the risk of industrial accidents. It’s no surprise that many U.S. states now support ending clock changes altogether.

The American Academy of Sleep Medicine and the American Medical Association have already endorsed permanent standard time as the safest and healthiest option for the population.