Daylight Saving Time Change May Have Long-Term Health Consequences

Every year, many area in North America, Europe, and select other regions observe Daylight Saving Time, the system of adjusting clocks forward and backward every year to adjust which parts of the day have the most daylight hours. The latest clock change happened over this past weekend, spurring the latest spat of conversations about this system and whether it is something that should continue in the future. Among the considerations are health consequences associated with this clock change.

According to researchers with Vanderbilt University Medical Center, the one-hour change that takes place twice a year is a big deal, at least from a health standpoint. The human body, as with animals and many plants, is very dependent on the daily light cycle for health; abruptly disrupting this cycle can cause short-term and long-term issues.

In the short term, this clock change may result in sleep loss, temporary cognitive issues, and slower reactions, potentially increasing the number of car wrecks and other issues the day after the clocks spring forward or fall back. During the DST transition, researchers found that adults face around 20 minutes of less sleep, which is enough to increase accident risk.

Beyond that, the DST light change results in a part of the year where the morning remains dark until a substantial period of time after most humans wake up. The lack of natural light to regular one's sleep cycle and encourage wakefulness in the morning can increase the risk of having a stroke or heart attack.

One of the researchers detailing the potential consequences, Beth Ann Malow, MD, explained, 'It's not one hour twice a year. It's a misalignment of our biologic clocks for eight months of the year.' Some people are more sensitive to this time change than others and may require weeks or months to fully transition to this new light cycle.