Permanent Standard Time Could Cut Strokes, Obesity Among Americans

* https://en.wikipedia.org/wiki/Chronobiology

AFAICT, all national (US, CA) and international (EU) chronobiology societies, as well as many sleep researchers, state that from a health perspective we should (a) get rid of the twice-yearly time switching, and (b) stay on Standard ("winter") Time year-round:

* https://srbr.org/wp-content/uploads/2018/10/SRBR-Statement-o...

* https://esrs.eu/wp-content/uploads/2019/03/To_the_EU_Commiss...

* http://www.chronobiocanada.com/official-statements

* https://sleepresearchsociety.org/wp-content/uploads/2022/11/...

* https://jcsm.aasm.org/doi/10.5664/jcsm.8780

* https://www.frontiersin.org/articles/10.3389/fphys.2019.0094...

https://archive.is/Ta2Fc

> The biannual shift between Daylight Saving and Standard Time leads to meaningful, negative societal health consequences. However, the biomedical impact of remaining in either time policy is poorly understood. By incorporating county-level solar light patterns, time policy, and health data with circadian models, we demonstrate that shifting to permanent Standard Time would lead to a decrease in the prevalence of stroke and obesity. A shift to permanent Daylight Saving Time would also result in a decrease, though less so than permanent Standard Time. These health impact patterns are highly dependent on both latitude and longitudinal position within a time zone. It will be crucial to consider these data in the ongoing debates surrounding time policy.

Study abstract:

> Seasonal changes in time policy, such as switching between Standard Time (SDT) and Daylight Saving Time (DST), have been adopted by many countries, including the United States. While transitioning between SDT and DST has notable acute negative population health impacts, the chronic impact of these time policies on health has not been well evaluated. To estimate the impact of permanent SDT or DST on health, we modeled the circadian impact of SDT, DST, and Biannual Shifting (BAS) across a year in the contiguous, continental United States. We find that BAS produces a greater burden on the circadian system as compared to either permanent SDT or DST. Chronotype as well as location (latitude and location within time zones) impact this burden. Analyzing these data relative to county-level health data (Centers for Disease Control and Prevention Places dataset), we find that, under idealized light exposure conditions and after controlling for health and socioeconomic factors, there would be a decrease in the prevalence of both obesity [0.78% (0.06% to 1.49%)] and stroke [0.09% (0.04% to 0.14%)] under SDT compared with the current policy. The prevalence of both obesity [0.51% (0.09% to 0.93%)] and stroke [0.07% (0.04% to 0.09%)] would also decrease under permanent DST, though to a lesser degree. Our data, reflecting the impact of time policy on circadian burden and subsequent health benefits, support the cessation of BAS.

* https://www.pnas.org/doi/abs/10.1073/pnas.2508293122#sec-1