Summary: New research reveals that artificial light at night disrupts more than sleep, affecting immune function, metabolism, mood, and brain health. Circadian rhythms, finely tuned over millions of years, regulate critical biological processes and can be thrown off by modern lighting and irregular schedules.
Clinical trials are now exploring how light-based interventions could improve outcomes for ICU patients, shift workers, and others at risk. The findings highlight the urgent need to align daily life more closely with natural light-dark cycles to support mental and physical well-being.
Key facts:
- Circadian disruption from artificial light impacts immune, metabolic, and mental health.
- Clinical trials are testing light interventions for ICU patients and shift workers.
- Recognizing time-of-day as a biological variable could improve research accuracy.
Source: Genomic Press
In a comprehensive Genomic Press Innovators & Ideas interview published today, distinguished neuroscientist Dr. Randy J. Nelson shares insights from his pioneering research on how disrupted circadian rhythms affect brain function and overall health.
The interview, published in Brain Medicine, traces Dr. Nelson’s unconventional path from farm work and autopsy assistant to becoming one of the world’s leading authorities on biological rhythms.
Dr. Nelson, who chairs the Department of Neuroscience at West Virginia University, has spent the past decade uncovering the hidden dangers of artificial light exposure. His research demonstrates that light at night doesn’t just affect sleep quality; it fundamentally alters immune function, triggers neuroinflammation, disrupts metabolism, and influences mood regulation.
From Turkey Processing Plant to Top Research Institution
The interview reveals Dr. Nelson’s remarkable journey to academic prominence. After working night shifts at a turkey processing plant during high school and later conducting postmortem examinations at two Cleveland hospitals, he eventually found his way to the University of California, San Diego, through an unexpected job opportunity at the San Diego Zoo.
“My path to academia is typical in the sense that it is not ‘typical,’” Dr. Nelson reflects in the interview. His unique background, including becoming the first person in the United States to simultaneously earn two separate PhDs (in Psychology and Endocrinology from UC Berkeley), shaped his integrative approach to neuroscience research.
Circadian Disruption: A Modern Health Crisis
Dr. Nelson’s laboratory has published groundbreaking findings on how exposure to artificial light at night affects multiple body systems. The research goes beyond simple sleep disturbance to reveal profound effects on physiological processes that evolved over millions of years to function in sync with natural light-dark cycles.
Key areas of impact identified by Dr. Nelson’s research include immune system dysfunction, where light exposure at inappropriate times can suppress typical immune responses or trigger excessive inflammation.
The work also demonstrates clear links between circadian disruption and metabolic disorders, potentially contributing to the obesity epidemic. Perhaps most concerningly, the research shows direct effects on mood regulation, with implications for understanding depression and anxiety disorders.
What specific wavelengths of light are most disruptive to circadian rhythms? How quickly can the body recover from chronic light exposure? What is the contribution of time-of-day as a biological variable? These questions drive ongoing investigations in Dr. Nelson’s laboratory.
Translating Discovery to Clinical Practice
Moving beyond foundational research, Dr. Nelson’s team currently conducts clinical trials examining whether blocking disruptive light effects can improve outcomes for intensive care patients. Two major trials focus on stroke recovery and cardiac surgery patients, populations particularly vulnerable to the harsh lighting conditions typical of hospital ICUs.
“Circadian rhythms are a fundamental aspect of biology, and much is known from foundational science about them,” Dr. Nelson explains. “However, little of this foundational science has been translated to clinical medicine.”
The research also extends to healthcare workers themselves. A third clinical trial investigates whether bright blue light visors can help night shift nurses reset their circadian rhythms, potentially improving their sleep quality, cognitive performance, and mood. Could similar interventions help other shift workers across various industries maintain better health despite irregular schedules?
Time as a Biological Variable
One of Dr. Nelson’s most provocative proposals involves recognizing time-of-day as a crucial biological variable in all research. He argues that experimental results can vary dramatically depending on when studies are conducted, yet this information rarely appears in scientific publications.
“The answer to an experimental question may depend in part on the time-of-day when the question is asked,” Dr. Nelson notes. This observation has profound implications for research reproducibility and could explain why some studies fail to replicate previous findings.
Building the Next Generation of Neuroscientists
Throughout his career at Johns Hopkins University, Ohio State University, and now West Virginia University, Dr. Nelson has mentored 25 PhD students and 16 postdoctoral researchers. His leadership philosophy emphasizes creating supportive environments where young scientists can thrive.
His mentoring philosophy has been featured in a recent Society for Neuroscience Neuronline podcast.
As current president of the Association of Medical School Neuroscience Department Chairs, Dr. Nelson advocates for resources and policies that support early-career researchers. He particularly values helping faculty members navigate the challenging early stages of their careers through strategic resource allocation and mentorship.
What role might circadian rhythm research play in addressing the mental health crisis among graduate students and postdocs? How can academic institutions better support work-life integration for researchers studying around-the-clock biological processes?
A Vision for Healthier Living
Dr. Nelson’s research carries immediate practical implications for public health. Simple interventions like reducing evening screen time, using warmer light colors after sunset, and maintaining consistent sleep schedules could significantly impact population health.
His work suggests that respecting our evolutionary heritage by aligning modern life more closely with natural light patterns could prevent numerous chronic health conditions.
He recently published a trade book with Oxford University Press entitled, “Dark Matters,” to help the general public appreciate the importance of good circadian hygiene for health and wellness.
About this circadian rhythm and health research news
Author: Ma-Li Wong
Source: Genomic Press
Contact: Ma-Li Wong – Genomic Press
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Disruption of circadian rhythms on brain function and health” by Randy J. Nelson et al. Brain Medicine
Abstract
Disruption of circadian rhythms on brain function and health
Randy Nelson studies sleep and circadian rhythms in health and illness. For the past 15 years, his lab has focused on the role of disrupted circadian rhythms on physiology and behavior.
He studies the effects of these disrupted circadian rhythms on several parameters including immune function, neuroinflammation, metabolism, sleep, and mood.
He has published nearly 500 papers and more than 12 books during his career describing studies in biological rhythms, behavioral neuroendocrinology, stress, immune function, and aggressive behavior.
He has been elected to Fellow status in several scientific societies. Nelson earned his AB and MA degrees in Psychology at the University of California, Berkeley. He earned a PhD in Psychology, as well as a second PhD in Endocrinology, both from UC Berkeley; he was the first in the US to simultaneously earn two PhDs. Dr. Nelson then completed a postdoctoral fellowship at the University of Texas, Austin, after which he joined the faculty at The Johns Hopkins University, where he became professor of Psychology, Neuroscience, Biochemistry, and Molecular Biology.
He then served on the faculty at The Ohio State University from 2000–2018, during which time he served as Distinguished University Professor and Chair of Neuroscience, as well as the co-director of the Neurological Institute.
Dr. Nelson was recruited to WVU in 2018 to serve as professor and inaugural chair for the new Department of Neuroscience. In addition to his NIH funding, he is Co-I of the NSF Track 1 award, ‘West Virginia Network for Functional Neuroscience and Transcriptomics’.
He has directly mentored 25 PhD and 16 postdoctoral colleagues. In this Genomic Press Interview Dr. Nelson shares insights into his personal and professional trajectories.