Study shows daylight saving time has minimal effect on heart health

adverse cardiovascular events occurred throughout the study during the spring and fall DST transition. An adverse cardiovascular event was documented when a person was hospitalized with a primary diagnosis of a heart attack, stroke, cardiogenic shock, or cardiac arrest.

“These cardiovascular events are common health conditions, so this led to the question of whether this is more than would be expected if this had not followed the daylight saving time transition,” says Dr. Satterfield.

The observance of daylight saving time varies around the world. Countries that move clocks forward or back one hour may do so on different dates, and some do not observe daylight saving time at all.

In the Mayo Clinic study, the Monday and Friday following the spring DST transition showed a statistically slight increase in the rates of cardiovascular events—but when looking at all the data, researchers did not see the rise as clinically significant, he said.

Researchers note that the time change practice was intended to align social and work activities with daylight hours and to conserve energy using less artificial lighting. They underscore that making changes to the DST system out of concern for heart health is unnecessary.

“When decisions are made about whether to abolish daylight saving time, there is no need to take concerns regarding heart health into account,” says Bernard J. Gersh, M.B., Ch.B., D.Phil., cardiologist and senior author of the study.

Dr. Gersh and Dr. Satterfield note that the debate over DST includes other aspects of health. For example, Dr. Satterfield said researchers are exploring DST’s effect on mental health and its effect on the rates of motor vehicle accidents.

The study is published in the journal Mayo Clinic Proceedings: Innovations, Quality & Outcomes.

More information:
Benjamin A. Satterfield et al, Daylight Saving Time Practice and the Rate of Adverse Cardiovascular Events in the United States: A Probabilistic Assessment in a Large Nationwide Study, Mayo Clinic Proceedings: Innovations, Quality & Outcomes (2024). DOI: 10.1016/j.mayocpiqo.2023.12.006