Daylight Savings: More Harmful than Helpful?​

What is Daylight Savings?

Daylight saving time (DST) was introduced in the United States just over 100 years ago, with hopes of conserving energy and allowing workers to take advantage of prolonged natural light.

The policy was also heavily backed by the  U.S. Chamber of Commerce because it would provide an extra hour of daylight for Americans after work, making them more likely to go out shopping. However, in none of these decisions did the government consider the safety, physical health, or mental health implications of such time changes.

The Impact of DST Shifts

Adjusting the time by one hour may not seem like a drastic change. However, sleep experts have noted that even seemingly trivial DST shifts are associated with adverse health consequences.

Negative Effects of DST on Physical Health

Shifting from standard time to DST has been linked to negative impacts on cardiovascular health, including an increased risk of heart attacksstroke, and irregular heartbeat. Frank Italiano, MD at Beam Healthcare said, “During the shift from daylight saving time back to standard time, we see a reduction in cardiovascular events and decrease in inflammatory markers. This is likely due to the
fact that standard time is more in line with the human circadian rhythm.”

Research has also shown that the number of missed medical appointments significantly increases during the spring forward clock change. Missed appointments represent a significant financial issue for healthcare systems and have an adverse impact on patient care. Improving appointment attendance rates would allow for more timely resolutions of health issues and therefore fewer
health complications.

The one-hour time shift in the spring is also associated with a rise in fatal traffic accidents, with research showing a 6% increase in the United States. DST raises safety concerns for teen drivers in particular, with a study conducted by the National Library of Medicine showing a cumulative sleep loss of over 2.5 hours a week and a decline in psychomotor vigilance. This raises serious public safety concerns, given that this population “includes inexperienced drivers and adolescents often trusted in the care of younger children.”

The springtime shift also has a negative impact on worker safety and productivity.  A higher rate of workplace injuries is reported during the shift, which researchers conclude is due to the effects of sleep deprivation. Sleep deprivation is associated with an impairment in cognitive performance, alertness, and attention.

For healthcare workers, these impacts extend beyond a loss of productivity. Research shows that the time shift is associated with
an increase in patient safety-related errors made by healthcare workers. This exposes patients to unnecessary harm, creates a burden that healthcare workers shouldn’t have to bear, and overall presents a major threat to public safety.

Negative Effects of DST on Mental Health

Both the transition into and out of DST has been associated with sleep disruption, mood disturbances, and suicide. In a study of over 185,000 patients, researchers found that the transition from DST to standard time increased the number of hospital visits for depression by 11%. Our circadian rhythm helps to regulate our daily schedule for sleep and wakefulness, and even a one-hour disruption can
have a significant impact on our mood and increase anxiety.

Our bodies look for the presence and absence of the sun to adjust the timing of our internal clock.

The light of the sun and darkness at night are the main signals that adjust the timing of our body clock

The sun travels from east to west, and research has shown that the further west people live within a time zone, the more health problems they may experience and the shorter they live on average. This is due to an increased difference between their social clock (created by humans) and body clock (circadian rhythm.) This is to say people further west within their time zone still have to start their day at the same time as those in the east, despite the delay in natural light. DST exacerbates these differences between social and biological time, leading to what is known as “social jetlag.”

In the long-run, these discrepancies are associated with negative impacts on mental health and an overall decreased life expectancy.

The scientific community has made remarkable progress in the past decade in our understanding of circadian rhythms and how they impact our behavior. Our knowledge of how DST shifts impact human health continues to expand and demonstrate the benefits of eliminating DST. Dozens of states have introduced legislation that would allow for changes to DST. Some states propose a switch to
permanent DST, while others are in favor of switching to permanent standard time.

Given that switching to daylight saving time disrupts sleep and leads to a variety of negative cognitive, health, and work outcomes, we recommend eliminating daylight saving time. This position is in line with the position of the American Academy of Sleep Medicine (AASM), which “supports the adoption of year-round standard time, which aligns best with human circadian biology and provides distinct benefits for public health and safety.”

 For these changes to take place would require a change to federal law. This change will take time, but it’s a great opportunity for sleep specialists to collaborate with policymakers to advocate for better sleep and better health.

Tips for Managing the Time Change

For now, DST is still a reality and it’s essential that we properly manage the time change. We recommend the following healthy sleep tips to limit the negative effects of DST:

  • Avoid electronics before going to bed.
  • Limit your caffeine and alcohol intake.
  • Gradually adjust your sleep/wake times 2-3 days before the time changes.
  • Take a short nap (20-30 minutes) if you need it.