Congress is nearing a decision to make daylight saving time permanent in the United States, though some health experts warn of potential negative health impacts. Efforts to establish this change have been ongoing for years, with proponents arguing that the shift could enhance economic activity and offer health benefits.
The Legislative Journey
The legislation, known as the Sunshine Protection Act, has passed the House with 308 members in favor and 117 against. It now awaits consideration by the Senate. If approved and signed by President Donald Trump, nearly all states will permanently adopt daylight saving time. This would mean an increase in evening daylight hours and a reduction in morning sunshine.
Health Concerns and Expert Opinions
While extended daylight in the evening might encourage activities like golfing or walking, experts doubt it will motivate non-exercisers to increase physical activity. Dr. Karin Johnson, a sleep medicine physician with the American Academy of Sleep Medicine, notes that studies indicate people sleep worse during daylight saving time and do not exercise more. Those who do exercise more are typically those who were already active, possibly changing their routine from morning to evening.
And more importantly than this, even if some people do exercise more, when the clocks are set that sunsets are an hour later, there’s over 10% more obesity rates,” Johnson said. “There’s higher heart disease rates. So we’re not seeing the health benefits of people being more fit. We are seeing exactly the opposite.
Adjustment to Permanent Daylight Saving Time
Many struggle with adjusting to the biannual time change. Experts like Johnson suggest that if daylight saving time becomes permanent, Americans may never fully adapt. The misalignment with natural circadian rhythms can hinder sleep-wake cycles.
Michael Grandner, director of the Sleep and Health Research Program at the University of Arizona, highlights the long-term health implications of living in a biologically later time system. Even slight reductions in sleep across a large population can have significant public health consequences.
Health Risks From Shifting Time
Dr. James Rowley from Rush University System for Health emphasizes the importance of morning light for regulating circadian rhythms. He warns that insufficient sleep increases risks of cardio-metabolic issues, including heart disease and high blood pressure. Poor sleep also affects the body’s vaccine response and raises cancer risks.
Teenagers could be particularly affected, as earlier school start times contribute to sleep deprivation. Studies show early high school classes are less productive, and social jet lag can lead to worse academic performance, depression, and obesity.
Geographical Variations and Impact
The effects of making daylight saving time permanent could differ based on geography. Grandner explains that individuals on the western edge of time zones may face larger biological shifts.
Understanding Daylight Saving Time Changes
The bill proposes keeping daylight saving time year-round, eliminating the biannual clock changes. States have had the option to refrain from daylight saving time since 1966, with Arizona and Hawaii choosing standard time. While Navajo Nation in Arizona still observes daylight saving time.
Differences Between Time Standards
Daylight saving time provides more light in the evening, while standard time offers more morning light. Current shifts between these times occur from early November to mid-March and mid-March to early November.
Senate Vote and Future Implications
No Senate vote is scheduled for the Sunshine Protection Act, but advocates push for prompt consideration. Health experts favor permanent standard time, which aligns better with natural sun patterns. A separate bill proposes permanent standard time, though its status remains uncertain after the House passage of the Sunshine Protection Act.
I think that the worst option is what we have now. Every year, we jet lag ourselves on purpose, for no good reason. Twice! Each time, it causes small but meaningful ripples in population health. Let’s stop these ripples once and for all,” Rowley said. “If the question is simply, ‘Which clock is more aligned with human biology?’ the evidence favors permanent standard time.