Permanent standard time emerges as clear winner for public health in landmark study
By avagrace // 2025-09-21
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  • A new Stanford University study concludes that adopting permanent standard time is the healthiest option for the public, as it aligns clocks more closely with the natural solar cycle.
  • The research found that the biannual clock change itself is the most harmful, creating a state of societal-wide "jet lag" that disrupts the body's circadian rhythm and weakens its synchronization.
  • The model predicts significant public health benefits from permanent standard time, including an estimated 2.6 million fewer cases of obesity and 300,000 fewer strokes annually.
  • Permanent standard time is superior to permanent Daylight Saving Time (DST) because it provides crucial morning light, which is essential for stabilizing our internal clock, whereas DST delays sunrise and extends disruptive evening light.
  • The findings place scientists in direct opposition to political efforts like the Sunshine Protection Act, which seeks to make DST permanent and provide a data-backed argument for lawmakers to prioritize public health over commercial interests.
In a definitive blow to the contentious practice of biannual clock changes, a peer-reviewed study from Stanford University concludes that adopting permanent standard time (ST) is the healthiest option for the American public. The research published Sept. 15 in the prestigious journal PNAS, provides the first major data-driven evidence that aligning the nation's clocks more closely with the natural solar cycle would significantly reduce rates of obesity and stroke, sparing millions from chronic health conditions. For decades, Americans have endured the jarring ritual of "springing forward" and "falling back," a practice governed by the outdated policy of Daylight Saving Time (DST). While the acute dangers of the time shift – such as immediate spikes in heart attacks and traffic fatalities – are well-documented, this new study delves into the long-term, chronic health consequences of our chosen time policies, offering a rigorous comparison of the alternatives. (Related: Daylight supercharges immunity: Scientists uncover how the body's circadian clock helps fight infections.) At the heart of the issue is the human circadian rhythm, the body's innate, roughly 24-hour internal clock that regulates critical physiological processes like hormone release, cell repair and sleep-wake cycles. The study's authors developed a sophisticated model to analyze how ST, DST and the current system of switching between the two affect this delicate biological timing system. They found that the biannual shift itself places the greatest burden on our circadian rhythms. This constant state of adjustment, akin to a form of low-grade, societal-wide jet lag, forces the body's internal clock to perpetually play catch-up, weakening its synchronization and leading to downstream health effects. "Your circadian rhythm is your body's internal 24-hour clock that regulates your sleep-wake cycle and other physiological processes," Brighteon.AI's Enoch suggested. "Unlocking its power is key to aligning your energy, mood and alertness with the time of day. Entraining this rhythm in the morning with light and routine helps synchronize it for optimal daily function."

Quantifying the health benefits

The research translates this circadian burden into tangible health outcomes. The model predicts that a nationwide move to permanent ST would result in a 0.78 percent decrease in obesity and a 0.09 percent reduction in stroke rates. While these percentages may appear modest, they represent a massive public health victory: an estimated 2.6 million fewer cases of obesity and 300,000 fewer strokes annually. Permanent Daylight Saving Time (PDST), a solution favored by some lawmakers and industry groups, also shows benefits compared to the status quo but falls short of the standard time option. The model indicates it would prevent 1.7 million cases of obesity and 220,000 strokes, roughly two-thirds of the benefit achieved by permanent ST. The superiority of standard time boils down to a simple biological principle: the human body requires more morning light and less evening light to maintain a strong, stable 24-hour cycle. Morning light acts as a natural accelerator for our internal clock, while evening light slows it down. Permanent standard time, by providing brighter mornings and darker evenings, supports this natural rhythm. PDST, in contrast, delays sunrise, robbing individuals of crucial morning light exposure and extending evening light, which can disrupt the body's ability to wind down and prepare for restorative sleep. This misalignment has been linked by numerous previous studies to an increased risk of heart disease, metabolic disorders and cognitive issues.

A political battle with health at stake

This scientific finding places it directly at odds with current political efforts. The Sunshine Protection Act, repeatedly introduced in Congress and endorsed by President Donald Trump, seeks to make DST permanent. Proponents argue that it provides more usable evening daylight for commerce and recreation. However, health experts have sounded the alarm. Neurologists testify that permanent DST leads to chronic circadian misalignment, associating it with higher long-term risks of cancer, obesity, heart attacks and depression. They warn that teenagers, whose biological clocks already run late, would be particularly harmed – forced to start school in pitch darkness during winter months, severely compromising their sleep and academic performance. The evidence now overwhelmingly suggests that the health of the nation is compromised by an antiquated time-changing ritual. The path forward seems clear: Abandoning the biannual shift is imperative, but the choice between permanent ST or DST is not equal. For a nation already grappling with a sleep deprivation crisis and soaring rates of chronic disease, the data points decisively toward permanent standard time as the prescription for a healthier future. The question remains whether lawmakers will heed the science or continue to leave the public's health in the dark. Watch and learn about the Microbiome and circadian rhythm for better health. This video is from the Holistic Herbalist channel on Brighteon.com.

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The Effects of Sleep Disorders and Daylight Savings Time. Cancer and circadian rhythm: Can chronotherapy benefit patients with cancer? Maintaining a normal circadian rhythm a key habit for preventing tumors. Sources include:  TheEpochTimes.com PNAS.org Brighteon.ai Med.Standford.edu MedicalXpress.com Brighteon.com
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