Dr. Randy J. Nelson is not your typical scientist.
Before he became one of the world’s leading experts on circadian rhythms — the body’s natural 24-hour clock — he worked in places far removed from research labs, including a turkey processing plant and hospital morgues.
His journey from those early jobs to chairing the Department of Neuroscience at West Virginia University is a story of curiosity, persistence, and a deep fascination with how time shapes life itself.
In a new interview published in Brain Medicine as part of the Genomic Press Innovators & Ideas series, Dr. Nelson reflects on his unconventional path and the groundbreaking discoveries his team has made about how modern life, especially artificial light at night, disrupts our biology in surprising and harmful ways.
Light at night is something almost everyone experiences — from glowing streetlights and bedside lamps to the blue light from our phones and TVs.
While many people think of it only as a possible sleep disturbance, Dr. Nelson’s research shows the impact is far greater. O
ver the last decade, his laboratory has found that exposure to light at the wrong times can throw off our immune system, cause inflammation in the brain, upset metabolism, and even affect mood. These systems evolved to work in harmony with the sun’s natural rise and set, and when that pattern is disturbed, the consequences ripple through the body.
His studies reveal that certain types of light, especially bright blue wavelengths common in electronic screens and hospital lighting, are particularly disruptive.
One key question driving his current research is how quickly the body can recover once the light exposure stops. Another is how much the time of day matters when it comes to both health outcomes and scientific experiments — a variable that he believes researchers often overlook.
Dr. Nelson’s work is not just theoretical. His team is now running clinical trials to see if controlling light exposure can improve recovery for hospital patients.
For example, two major studies are testing whether blocking disruptive light can help people heal after strokes or heart surgery. These patients often stay in intensive care units with harsh lighting 24 hours a day — an environment that may slow recovery.
His research also looks at the people who care for patients. One trial is testing bright blue light visors for night-shift nurses to help reset their circadian rhythms. Better alignment between their internal clocks and work schedules could improve sleep, mental health, and job performance.
Beyond healthcare, Dr. Nelson sees circadian science as a public health opportunity. Simple steps like dimming lights in the evening, choosing warmer colors after sunset, and sticking to regular sleep times could help reduce risks for chronic conditions like obesity, diabetes, and depression.
He recently shared these ideas in his book Dark Matters, written for general readers who want to protect their health by respecting their body’s natural timing.
Throughout his career at Johns Hopkins, Ohio State, and West Virginia University, Dr. Nelson has mentored dozens of PhD students and postdoctoral researchers.
As president of the Association of Medical School Neuroscience Department Chairs, he advocates for early-career scientists, arguing that institutions should provide resources and policies that help them balance demanding research with personal well-being.
His story is also about balance in his own life. When not in the lab, he enjoys traveling, biking, and gardening — activities that keep him connected to the natural rhythms he studies. His favorite place is still Southern California, where decades ago, a job at the San Diego Zoo set him on his scientific path.
The message from Dr. Nelson’s work is clear: our bodies are designed to live in step with the light and dark of the natural world. Disrupting that rhythm, as modern life so often does, can take a serious toll. By paying more attention to when we are exposed to light — and making small adjustments — we can protect our health and well-being.
This interview not only showcases Dr. Nelson’s personal and professional journey but also highlights a growing body of evidence that circadian disruption is a major health issue. His research moves the conversation beyond sleep to include immune health, brain inflammation, metabolism, and mood regulation.
The clinical trials in hospitals and with shift workers are a crucial next step in translating lab discoveries into real-world benefits. Perhaps most importantly, his call to treat time-of-day as a key factor in all research could improve the reliability and relevance of scientific findings across many fields.
The practical message is that managing light exposure — especially in the evening — is a simple, low-cost step we can all take toward healthier living.
If you care about mental health, please read studies about Cannabis use disorder linked to increased risk of these mental diseases and findings of Some mental health drugs can cause rapid weight gain.
For more information about mental health, please read studies about One sleepless night can reverse depression for days and findings of Scientists find better treatment for older adults with depression.
The study is published in Brain Medicine.
