The Impact of Time Changes on Health

As autumn approaches, many in the United States prepare to adjust their clocks for the winter time change. However, this adjustment may have effects beyond just altering sleep schedules. Recent research suggests that these time changes can significantly impact public health. A recent study published in the Proceedings of the National Academy of Sciences in the United States indicates that eliminating these time changes and permanently adopting standard time could help reduce obesity and stroke rates.

Standard Time vs. Daylight Saving Time: Which is Better for Health?

The study conducted by researcher Lara Wade from Stanford University suggests that permanent standard time may offer greater health benefits on a population level. It indicates that policymakers should consider disease rates in their states when making decisions about timekeeping.

These findings support previous research showing that the annual switch between standard time and daylight saving time increases the risk of heart attacks, traffic accidents, sleep disorders, and reduced productivity. Many global scientific associations, including the American Medical Association and the American Academy of Sleep Medicine, have expressed their opposition to these time changes, noting that increased morning light exposure provided by standard time can help mitigate these issues.

How Do Time Changes Affect the Internal Biological Clock?

To analyze the effects of timekeeping, researchers built computer models to simulate how light exposure affects people’s biological rhythms and health under permanent standard time, permanent daylight saving time, and the current semi-annual time change system. These simulations were integrated with a mathematical model of the biological clock, taking into account geographical factors like latitude and longitude.

The results showed that most people would experience fewer disruptions to their biological rhythms under permanent standard time, with greater morning light exposure. Estimates suggest that adopting permanent standard time could lead to a reduction in obesity prevalence by about 0.8%, which translates to approximately 2.6 million fewer people suffering from obesity in the United States. Additionally, stroke prevalence could decrease by 0.09%, representing over 300,000 fewer cases.

Challenges and Limitations of the Study

Despite the positive findings, researcher Roxanne Prichard from the University of St. Thomas in Minnesota points out some limitations of the study. The study assumes that most people work between 9 AM and 5 PM, while a 2024 survey showed that 16% of the American population works non-standard hours, a factor that should be considered in future studies.

The study’s model also did not include other health data such as car accidents, suicide rates, or drunk driving incidents, which might also change with different time policies. Researchers did not find significant effects on other chronic conditions like diabetes, cancer, arthritis, and depression.

Conclusion

Although the results are merely computer simulations, they align with the stance of scientific organizations that permanent standard time could help prevent some public health and safety issues. However, Wade emphasizes the need for more studies to examine the potential economic and social impacts of adopting permanent standard time in the United States. The U.S. government experimented with permanent daylight saving time in the 1970s, but the trial ended due to public backlash and concerns about children going to school in the dark and increased car accidents. Other countries, like Mexico, abolished time changes in most areas in 2022, claiming that permanent standard time improves safety, boosts productivity, and reduces energy consumption. The data is clear: permanent standard time is the healthier choice.