Daylight saving time: Health risks and how to adjust to losing an hour of sleep

Daylight saving time arrives this weekend, which means it’s once again time to move the clocks ahead an hour. The change, which takes effect at 2 a.m. this Sunday, will cost millions of Americans an hour of sleep and leave many of us feeling extra groggy. Health experts say there can also be some more serious consequences.

“The main impact of daylight savings time is the loss of sleep and the need to ‘shift’ the timing of sleep after the clocks change. This has two consequences,” Dr. M. Safwan Badr, a pulmonologist at DMC’s Detroit Receiving Hospital, told CBS News. “First, missing an hour of sleep makes people sleepy, especially if their sleep time is already short the week before.  Furthermore, It takes most people several nights to shift their circadian rhythms and get their sleep back on track.”

The disruption in sleep patterns can have a number of effects on your health.

Mood, memory, and concentration

Perhaps the most common and noticeable way the loss of sleep affects people is through changes in mood and productivity. On average, Americans lose 40 minutes of sleep when we set the clocks ahead in the spring. Increased irritability is common

Sleep disruptions can also affect memory, performance and concentration levels. A 2012 study published in the Journal of Applied Psychology found that shifts related to daylight saving time led to a dramatic increase in “cyber loafing” — killing time on the internet instead of working.

Workplace injuries and car crashes

Additionally, sleep deprivation can lead to more workplace injuries and car crashes. One study looking at data on over 500,000 mining injuries from 1983 to 2006 found a 5.7 percent increase on the Monday following the time change. Even more worrisome, the injuries were more severe, leading to a 68 percent increase in the number of days of work missed.

According to research from AAA, drivers who miss two hours of the recommended amount of sleep in a 24-hour period can nearly double their risk for a crash.

Heart attacks and stroke

Perhaps most concerning, research has found that setting the clocks ahead an hour can take a toll on your heart. A study published last year found daylight saving time transitions may be tied to an increased risk of a common type of stroke. 

Researchers analyzed over a decade of stroke data and found that the overall rate of ischemic stroke — which accounts for the majority of stroke cases and is caused by a clot blocking blood flow to the brain — was 8 percent higher during the first two days after a daylight saving time transition.

Another study published in 2014 found that the time change was also associated with higher short-term risk of a heart attack.

Tips for adjusting to daylight saving time

Badr notes that the daylight saving time adjustment can be harder on some people than on others.

“The time changes can be particularly difficult for people with sleep disorders such as insomnia or for people who are shift workers and already struggle to protect enough time for sleep,” he said. “The spring time changes is especially difficult for teenagers, who struggle to get up early for school and have a hard time advancing their sleep schedule to an earlier time.”

But there are some steps you can take to help.

“Plan ahead. Allow time to adjust. Stick to healthy sleep habits. Reset your clocks Saturday afternoon, and if you are sleepy, go to bed a little early Saturday evening,” Badr said.

The American Academy of Sleep Medicine recommends the following tips to reduce the health effects of daylight saving time:

• Get at least seven hours of sleep (for adults) or eight hours of sleep (for teens) each night in the days before and after the clocks move ahead.
• Gradually adjust your sleep and wake times beginning two to three nights before the time change by shifting your bedtime 15 or 20 minutes earlier each night.
• For a few days before the clocks move ahead, begin to adjust the timing of other daily routines that are “time cues” for your body. This could mean starting dinner a little earlier each night.
• Head outdoors for some early morning sunlight on Sunday. The bright light will help set your internal clock, which regulates sleep and alertness.
• Go to bed early enough on Sunday night to get plenty of sleep before the week begins on Monday.