Abstract
There’s a time and the time is now and it’s right for me, It’s right for me, and the time is now.
The study of biological rhythms is coming of age. The notion of temporal control has certainly pervaded all fields of biology and is currently recognized as a critical variable for most research. Moreover, the mechanisms underlying circadian clocks are still being unveiled and receiving full attention from the scientific community (notwithstanding the recent concession of the Nobel prize to three outstanding researchers in our field). But this is far from attaining the full impact of chronobiology. Indeed, biological rhythmicity is gaining momentum as we realize its applications outside the lab, in real-life situations of huge social interest. For example, discussions about ending Daylight Saving Time (DST) can be informed by science (examined in the recent Society for Research on Biological Rhythms (SRBR) Position Paper by Roenneberg et al., J Biol Rhythms 34: 227-230, 2019).
This issue of the Journal features a series of SRBR Public Outreach Briefs, addressing four topics that exemplify the social implications of emerging chronobiological knowledge about the importance of: light exposure patterns for the circadian system, school start times, when to eat, and chronomedicine. The SRBR asked international experts in their respective fields to briefly describe the state of our understanding on these issues. The authors aimed to avoid technical jargon and extra details to maximize accessibility for the general public and policymakers. These Outreach manuscripts are designed as accessible introductions to the consequences of living in a 24-hour society from a chronobiological perspective, with the goal to benefit educators, clinicians, industry representatives, politicians, families, and other decision-makers. They focus on describing the state of our field and our general understanding of the respective topics, as of today.
The Outreach Brief by Vetter et al. examines how different aspects of light exposure – including its timing, wavelength, and intensity – impact our circadian system, physiology, and behavior. We have evolved as a diurnal species, although urbanization and electric light accessibility have altered our day and night light exposure patterns, with previously unforeseen consequences for our quality of life and health. This paper is geared to emphasize the importance of light at all times of day, and summarizes some key light hygiene rules from a chronobiological perspective for day-working, healthy populations.
As scientists, parents, and educators, we have long known that the daily schedules of adolescents depart from their younger colleagues: Teenagers are on average naturally owls, tending toward nocturnality. Thus, as teens drift towards later hours, they find their biology misaligned with the early hours of school start time. Dunster et al. provide a summary of the evidence that this misalignment due to the delay in teenage biology can be addressed by a concomitant delay in the start of classes. Studies around the world not only suggest but, in some cases, demonstrate that delaying school start times by 30-60 minutes results in improvements such as longer sleep duration, less tardiness and sickness, and better test scores. The Outreach Brief illustrates how chronobiological principles can be applied to design healthy school schedules.
The last two Briefs of the series address questions about the best times of day for eating and taking medicines. Manoogian et al. provide evidence demonstrating that the timing of food intake affects health significantly. The authors offer clues regarding the duration of daily eating, the precise timing of the daily eating interval and its calorie distribution and indicate evidence-based strategies for optimal meal timing. Restricting eating to intervals of less than 12 hours/day (during the hours of light), eating most calories in the earlier part of the day and avoiding food intake late at night appear to have significant health benefits, from better sleep to weight control. It is not (only) what you eat. . . but when you eat.
Finally, Smith et al. highlight the significance of chronopharmacology, adjusting the time for drug treatments to increase desired effects, while reducing side-effects. They review a variety of commonly used drugs which clinicians prescribe, and patients consume, according to time of day. The authors focus on FDA-labeled drugs to illustrate the potentially massive relevance for the timed treatment of many diseases.
All of the Public Outreach Briefs were anonymously reviewed by peer experts in the field. Reviewers provided invaluable insights and recommendations. Following revisions by the authors, the SRBR Executive Board approved the four manuscripts for publication. The Board and the Editor-in-Chief of JBR wish to thank the following reviewers for dedicating their time and effort to SRBR’s first step to true outreach and for navigating this new format with us: Drs. Molly Bray, Carolina Escobar, Mariana Figueiro, Carla Finkielstein, Russell Foster, Joshua Gooley, Claude Gronfier, Achim Kramer, Rob Lucas, Judith Owens, Courtney Peterson, Frank Scheer, Russell Van Gelder, Eva Winnebeck, and Kenneth Wright, Jr. We also thank Dr. Marta Wegorzewska for her editorial comments aimed at making each Brief understandable to a broad audience.
SRBR also has launched Infographics for each Public Outreach Brief, designed by the BioClock Studio of UC San Diego and under the supervision of Dr. Susan Golden. They can be found on the SRBR and the BioClock Studio websites, and provide a graphical summary aimed to promote accessibility and discussion. We are grateful to Dr. Golden and all students who made this possible. Finally, our warmest acknowledgment to JBR’s Editor-in-Chief Dr. William Schwartz for his tireless promotion of the field, and in particular, his invaluable help supporting this public outreach effort, and its publication in the Journal.
As scientists, we have the responsibility for communicating and sharing our discoveries, so that our science ultimately reaches the general public, both as the infectious and fascinating spread of general knowledge, but also as advice and solutions for social problems and demands. We are convinced that these four initial SRBR Public Outreach Briefs will eventually serve both purposes.
We are the stuff that rhythms are made of. Let’s spread the word.
Footnotes
Scan this QR code to go to the infographics that accompany each Public Outreach Brief.