PacSci Perspectives

Daylight Saving Time Increases Stroke Risk

by | Mar 9, 2016

We’re turning clocks forward this weekend, and new research has found a link between the one-hour sleep disruption and increased risk of ischemic stroke.

Ischemic stroke is the most common kind of stroke, accounting for 87 percent of all cases. It is caused by a clot blocking blood flow to the brain.

“Previous studies have shown that disruptions in a person’s circadian rhythm, also called an internal body clock, increase the risk of ischemic stroke, so we wanted to find out if daylight saving time was putting people at risk,” said study author Jori Ruuskanen, MD, Ph.D, of the University of Turku in Turku, Finland.

Looking at a decade of data, researchers compared the rate of stroke in 3,033 people hospitalized in Finland during the week following a daylight saving time transition to the rate of stroke in a group of 11,801 people hospitalized two weeks before and after that week.

The overall rate of ischemic stroke was eight percent higher during the first two days after a daylight saving time transition. There was no difference after two days. People with cancer were 25 percent more likely to have a stroke after daylight saving time than during another period. People over age 65 were 20 percent more likely to have a stroke right after the transition.

The research will be presented next month at the American Academy of Neurology’s 68th Annual Meeting in Vancouver, Canada.

While the exact mechanism behind increased stroke risk has not yet been identified, other studies have shown links between sleep rhythm disruptions and metabolic, physiologic, and behavioral changes.

Earlier research has linked the semi-annual time changes to more vascular events, traffic accidents, suicides and cyberloafing. Even one hour matters when it comes to shortchanging sleep. In the three days following the spring-forward time change, researchers found a five percent greater risk of heart attacks.

If you’re not getting enough sleep, you risk damaging memory, learning, creativity, productivity, emotional stability and physical health. You’re also more vulnerable to cancer, diabetes, weight gain, colds and flu and car accidents!

The good news is that even though we lose an hour of sleep during the “spring forward” time change, it offers a chance to tune-up sleep habits.

Here are some tips to start preparing your body for disrupted sleep come March 13.

First, figure out how much sleep is enough.

Most adults: 7 – 9 hours a night
Adolescents: 9 – 10 hours
Elementary school children: 10 hours
Preschoolers: 11 – 12 hours
Newborns: 16 – 18 hours

This year, mitigate the negative symptoms of the clock-change.

Create A Fake Sunset
Dim the lights and avoid screen time at least an hour before your new bedtime. Or wear orange glasses that block blue light.

Early in the day, preferably in bright light to rev up serotonin, which helps regulate circadian rhythms.

Create A Fake Sunrise
Put a timer on a bright light near your bed. Set it to turn the light on 30 minutes before you want to wake up in the morning.

Give Yourself A Bonus Hour
If you’re already chronically sleep-deprived, add an extra hour to your sleep schedule starting now. Tonight, go to bed an hour earlier, but don’t wake up an hour earlier tomorrow morning.

Visit Wellbody Academy’s Slumbertorium for sleep tips, fun facts and to learn more about working with your body’s natural circadian rhythms. (You’ll love the Rube Goldberg-like Sleep Machine!)