How springing forward to daylight saving time could affect your health

WASHINGTON– Most of America “jumps ahead” on Sunday to Daylight Saving Time. Losing that hour of sleep can do more than leave you tired and grumpy the next day; it could also harm your health.

Darker mornings and more light in the evening disrupt your body clock, meaning DST can cause sleep disturbances for weeks or longer. Studies even found a slight increase in heart attacks and strokes right after the March time change.

There are ways to make adaptation easier, including getting more sunlight to help you reset your circadian rhythm and enjoy healthy sleep.

Daylight saving time begins at 2 a.m. Sunday, with an hour of sleep disappearing in most of the United States. The ritual will reverse on November 1 when the clocks “fall back” at the end of daylight saving time.

Hawaii and most of Arizona don’t make the spring change, sticking to standard time year-round — along with Puerto Rico, American Samoa, Guam and the U.S. Virgin Islands. Around the world, dozens of countries also observe daylight saving time, starting and ending on different dates.

Some people try to prepare for daylight saving time by going to bed a little earlier two or three nights in advance. While getting back on schedule after a one-hour change isn’t that difficult for some people, it’s an added challenge for the third of American adults who already don’t get the recommended seven hours of nightly sleep.

The brain has a master clock that is set based on exposure to sunlight and darkness. This circadian rhythm is an approximately 24-hour cycle that determines when we become sleepy and when we are more alert. Patterns change with age, one reason why young people who mature early become difficult-to-wake teenagers.

Morning light resets the rhythm. In the evening, levels of a hormone called melatonin begin to increase, triggering sleepiness. Too much light in the evening – this extra hour compared to summer time – delays this increase in power and the cycle becomes desynchronized.

Lack of sleep is linked to heart disease, cognitive decline, obesity and many other problems. And this circadian clock affects more than just sleep, also influencing things like heart rate, blood pressure, stress hormones, and metabolism.

Fatal car crashes temporarily increase in the first days after the spring time change, according to a study of U.S. traffic fatalities. The risk was higher in the morning and the researchers attributed it to lack of sleep.

Then there is the heart connection. The American Heart Association points to studies that suggest an increase in heart attacks on Mondays after daylight saving time changes, and in strokes for two days afterward.

Doctors already know that heart attacks, especially serious ones, are generally a little more common on Mondays – and in the morning, when blood is more prone to clots.

Researchers aren’t sure why the time change would add to this Monday connection, but it’s possible that the abrupt circadian disruption could exacerbate factors like high blood pressure in people already at risk.

Get outside to enjoy the early morning sun during the first week of daylight saving time, which can help reset your body’s internal clock. Increasing daily routines, like dinner time or when you exercise, can also help your body begin to adapt, sleep experts advise.

Afternoon naps, caffeine, and evening light from phones and other electronic devices can make it even harder to adjust to an earlier bedtime.

Every year there is talk of ending the time change. Before beginning his second term, President Donald Trump promised to eliminate daylight saving time. A bipartisan bill called the Sunshine Protection Act, aimed at making daylight saving time permanent, has repeatedly stalled in Congress.

But that’s the opposite of what some health groups recommend. The American Medical Association and American Academy of Sleep Medicine agree it’s time to ditch timers, but say sticking to standard time year-round better aligns with the sun — and human biology — for more consistent sleep.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Education Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.