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The Health Dangers of Daylight Saving Time

Losing your life, in addition to that hour?

Late last month, the American Academy of Neurology released preliminary results from a study, the conclusion of which being that turning the clock ahead or back one hour during daylight saving time transitions may be tied to an increased risk of stroke—the overwhelming type of stroke being ischemic (the result of a blood clot blocking oxygen-enriched blood flow to the brain).

Actually, this is not so surprising: prior studies have shown that disruptions in an individual’s internal body clock increase the risk of cardiovascular events: rotating shift work and sleep fragmentation are associated with an increased risk of stroke. The Monday and Tuesday after daylight saving time in the spring have also been associated with a 10% increase in heart attacks, according to a 2012 study from the University of Alabama. What is common in these situations is the disturbed sleep cycle, while the immediate mechanisms for the increased risk are unknown at the moment.

In this recent study, researchers looked at stroke data in Finland, comparing the rate of stroke in 3,033 people hospitalized during the week following a daylight saving time transition to the rate of stroke in a group of 11,801 people hospitalized either two weeks before or two weeks after that week. Interestingly, the researchers found that the overall rate of ischemic stroke was 8 percent higher during the first two days after a daylight saving time transition. But this uptick was short-lived, as there was no difference after two days.

The risk was higher for those over age 65, who were 20 percent more likely to have a stroke right after the transition.

To combat the effects of this twice-yearly time transition, the National Sleep Foundation recommends sleeping late on Sunday morning, and taking a nap that afternoon.

And if your doctor has already suggested it, I would suggest that you don’t forget to take your aspirin tonight.