If you spend enough time exploring circadian health, you will probably reach the same questions almost everyone eventually asks: 

"If this information is so important, why has my doctor never mentioned it?"

Or, "Why am I being told this isn't legitimate?"

They are fair questions.

After all, if light, circadian rhythms, and our relationship with the environment influence nearly every aspect of human biology, why are these topics rarely discussed during routine medical appointments? Why do so many physicians recommend avoiding the sun, while many people in this field encourage regular sunlight exposure? And why do ideas that draw from established scientific disciplines like chronobiology, photobiology, mitochondrial biology, and biophysics sometimes get dismissed before they're even discussed?

The answer is more nuanced than many people expect.

It is not because physicians do not care. In my experience, most physicians genuinely want the best for their patients, even within modern healthcare systems that often limit their ability to practice medicine the way they would like, leaving little time to explore emerging research or address the environmental factors that may contribute to chronic disease. Medicine itself is also constantly evolving, and it often takes 10 or more years, sometimes as many as 17 depending on the field, for new research to become part of routine clinical practice.

Before new discoveries are incorporated into medical school curricula, clinical guidelines, specialty boards, and standards of care, they must first survive years of additional research, replication, peer review, and debate. That process exists for good reason. Patients deserve treatments that have been thoroughly investigated, and physicians have a responsibility to practice evidence-based medicine.

The downside, however, is that by the time new discoveries become common knowledge in the clinic, researchers have often already moved on to asking the next generation of questions.

I believe that is exactly where we are today with circadian biology.

Science Is Always Evolving

One of the greatest strengths of science is that it is willing to change.

Throughout history, ideas once accepted as unquestionable have later been revised, refined, or even abandoned as better evidence emerged. Likewise, discoveries that were initially dismissed have sometimes become foundational to modern medicine.

That does not mean every new idea is correct, nor does it mean every old idea was wrong.

It simply reminds us that science is not a fixed collection of facts. It is an ongoing process of asking better questions, gathering better evidence, and refining our understanding of how the world works.

This has happened countless times throughout the history of medicine. Peptic ulcers were once thought to be caused primarily by stress before researchers demonstrated the central role of Helicobacter pylori. Nutrition guidelines have changed repeatedly as our understanding of metabolism has evolved. Even recommendations surrounding hormones, cholesterol, dietary fat, and many common medications have shifted as new evidence has emerged.

None of this should reduce our confidence in medicine. If anything, it should increase it.

Good science is willing to question itself.

That is one of the reasons I find circadian biology so exciting. It asks whether there are additional questions worth exploring about how the environment shapes human health.

I believe the answer is yes.

Why These Conversations Can Become So Polarized 

One challenge is that conversations about health do not happen in a vacuum.

Over the past several years, topics such as sunlight, environmental toxins, chronic disease, nutrition, and circadian biology have increasingly become intertwined with broader cultural and political conversations. As a result, ideas are sometimes accepted or rejected based less on the underlying evidence and more on the people or communities discussing them.

I think that is unfortunate.

Scientific ideas should ultimately be evaluated on the totality of the evidence supporting them. That includes published research, thoughtful scientific debate, clinical experience, and the real-world outcomes practitioners consistently observe over time. Research is an essential part of that process, but like all human endeavors, it is influenced by funding priorities, publication practices, and the questions researchers choose to investigate. No single study, or even a collection of studies, should be viewed in isolation. Unfortunately, once a topic becomes associated with a particular public figure or political movement, it often becomes much harder for people to evaluate the broader body of evidence on its own merits.

That does not mean every circadian health claim you hear is correct, nor does it mean every criticism is unfounded. As with any evolving field, there are thoughtful researchers, experienced clinicians, bold hypotheses, unsupported claims, and ideas that ultimately may not withstand further investigation. And yes, that includes people like me. Anyone with a platform can make a compelling claim. Rather than accepting or rejecting an idea based on who says it, I encourage people to evaluate the totality of the evidence, including the scientific literature, clinical experience, historical observation, and real-world outcomes.

But dismissing an entire body of research because of the personalities associated with it serves no one.

The better question is always: What does the evidence actually say?

That is the question I hope more people continue asking.

Sunlight Is a Perfect Example

Perhaps no topic illustrates this better than sunlight.

For decades, public health messaging has focused on reducing ultraviolet (UV) exposure to lower the risk of skin cancer. Sunscreen, protective clothing, and limiting midday sun exposure became common recommendations, and for many people, avoiding the sun altogether came to be viewed as synonymous with protecting their health.

However, sunlight is far more than ultraviolet light.

Natural sunlight is a full spectrum of light that includes visible light, near-infrared, and far-infrared wavelengths alongside UV, all of which interact with the body in different ways. Yet much of the historical research informing modern public health recommendations examined isolated ultraviolet wavelengths rather than the complete solar spectrum humans actually experience outdoors.

That distinction matters because isolated UV exposure is not the same as experiencing natural sunlight.

Researchers are increasingly exploring how different portions of the solar spectrum work together rather than independently. For example, infrared light has been shown to support mitochondrial function and may influence how the body responds to UV exposure, prompting important questions about whether studying UV in isolation fully captures how the body experiences natural sunlight.

In other words, the conversation is becoming more nuanced.

Rather than asking whether sunlight is simply "good" or "bad," researchers are increasingly asking how different wavelengths interact, how the timing of light exposure influences biology, and how the complete solar spectrum supports human physiology.

Those are very different questions than medicine was asking several decades ago, and I believe they will continue reshaping how we think about health in the years ahead.

The Forgotten History of Heliotherapy

One of the most fascinating aspects of this conversation is that using sunlight as medicine is not a new idea.

Long before antibiotics became widely available, physicians throughout Europe and North America regularly prescribed carefully controlled sunlight exposure as a legitimate medical treatment, a practice known as heliotherapy. Entire hospitals, clinics, and sanatoria were intentionally designed around access to fresh air and abundant natural light. Patients recovering from chronic illnesses often spent hours each day outdoors under the supervision of their physicians, with sunlight considered an important part of the healing process rather than something to avoid.

Some of the most influential physicians of the era built entire careers around this work.

Perhaps the best known was Swiss physician Dr. Auguste Rollier, who became internationally recognized for treating thousands of patients with carefully dosed sunlight exposure in the Swiss Alps. His clinics attracted patients from around the world, and his 1923 book, Heliotherapy, documented both his philosophy and clinical experience. Around the same time, Danish physician Dr. Niels Ryberg Finsen was awarded the 1903 Nobel Prize in Physiology or Medicine for his pioneering work using light therapeutically to treat disease.

At the time, sunlight was commonly used in the treatment of conditions such as tuberculosis, rickets, chronic wounds, certain skin diseases, and other illnesses. Whether every historical treatment would hold up under today's scientific scrutiny is almost beside the point. What matters is that sunlight was once regarded as an important therapeutic tool by many respected physicians, hospitals, and researchers.

Today, that history is rarely discussed.

Medicine did not abandon heliotherapy because someone suddenly proved sunlight was harmful. Rather, healthcare changed dramatically throughout the twentieth century. The discovery of antibiotics, the rapid growth of pharmaceuticals, advances in surgery, improved sanitation, vaccination programs, and countless other breakthroughs understandably shifted medicine's focus toward interventions that could be standardized, measured, and scaled.

Those advances transformed healthcare and have undoubtedly saved millions of lives.

But as medicine increasingly specialized, many of the environmental factors that had once been considered part of everyday health, including sunlight, fresh air, sleep, seasonal living, and our relationship with the natural world, gradually became less central to the conversation.

We seem to have lost something valuable along the way.

That does not mean we should return to practicing medicine exactly as physicians did one hundred years ago. We know far more today than they did, and many modern medical advances have been extraordinary.

What it does suggest is that some older observations may deserve another look through the lens of modern science. Today, researchers have tools those early physicians could never have imagined. We can study mitochondrial function, circadian biology, nitric oxide production, exclusion-zone water, gene expression, and countless other biological processes that help explain why sunlight appeared to benefit so many people long before we understood the mechanisms behind it.

Perhaps those physicians were observing something real all along.

We Are Asking Better Questions

To me, that is one of the most exciting aspects of circadian health.

Rather than claiming to have all the answers, this field is asking questions that, until relatively recently, were not being asked very often.

• How does the timing of light exposure influence hormones and metabolism?
• How do different wavelengths of light work together throughout the day?
• What role do mitochondria play in sensing and responding to the environment?
• How does the body use natural sunlight differently than artificial light?
• How do our modern indoor lifestyles influence biology in ways our ancestors never experienced?

These are not philosophical questions.

They are scientific ones.

Every year, researchers publish new studies exploring the relationship between light, circadian rhythms, mitochondrial function, sleep, metabolism, cardiovascular health, immune function, mental health, and countless other aspects of human biology.

We are still early in that journey.

Some ideas will undoubtedly be refined. Others may eventually be disproven. New discoveries will almost certainly raise questions no one has thought to ask yet.

That is exactly how science should work.

And it is one of the reasons I find this field so exciting.

Why Circadian Health Is Beginning to Gain Momentum 

While many aspects of circadian health have not yet become part of routine medical practice, that is beginning to change.

Over the past decade, researchers have dramatically expanded our understanding of chronobiology, photobiology, mitochondrial biology, and the relationship between the environment and human health. As a result, concepts that were once discussed primarily within smaller scientific and educational communities are increasingly entering mainstream conversations.

Today, physicians, researchers, and science communicators such as Andrew Huberman regularly discuss topics like circadian rhythms, morning sunlight, artificial light exposure, sleep timing, and the biological effects of light. Entire research centers are now dedicated to understanding how our internal clocks influence metabolism, cardiovascular health, immune function, mental health, and longevity.

That is encouraging.

At the same time, the broader framework taught within circadian health, one that views environmental signals as foundational drivers of mitochondrial function and overall health, has not yet been widely integrated into mainstream healthcare. Many physicians are familiar with individual pieces of the puzzle, but fewer have been trained to view those pieces as part of a larger, interconnected biological system.

I suspect that will continue to change.

Medicine has always evolved by integrating new discoveries into existing knowledge rather than replacing everything that came before. I believe circadian biology is following that same path. Rather than competing with modern medicine, it has the potential to enrich it by providing a deeper understanding of how the environment shapes human physiology long before disease develops.

FAQs

Why do some doctors dismiss circadian health as pseudoscience? 
Scientific ideas are sometimes judged as much by who is discussing them as by the evidence itself. Because conversations about circadian health have become intertwined with social media, politics, and public debate, some people dismiss the topic before examining the underlying research. I encourage people to look beyond personalities and evaluate the science itself. Many of the concepts discussed within circadian health are grounded in established scientific disciplines such as chronobiology, photobiology, mitochondrial biology, and biophysics.

Why does it take so long for new medical research to become common practice?
Research does not become standard medical care overnight. Before new discoveries are incorporated into medical education, clinical guidelines, and standards of care, they must be replicated, debated, evaluated, and shown to improve patient outcomes. Depending on the field, that process often takes 10 years or more and, in some cases, as many as 17 years.

Is there research supporting the health benefits of sunlight?
Yes. A growing body of research has explored the relationship between natural light and circadian rhythms, sleep, hormone production, cardiovascular health, mitochondrial function, metabolism, mental health, immune function, and many other aspects of human biology. While researchers continue to refine our understanding, the scientific literature surrounding light biology has expanded dramatically over the past two decades. If you would like to explore the research yourself, I have compiled many high-quality scientific papers on my Science page.

If my doctor isn't familiar with circadian health, should I ignore their advice?
No. In fact, I do not provide medical advice. Conventional medicine and circadian health also do not need to be viewed as competing approaches. I encourage people to work collaboratively with qualified healthcare professionals while continuing to educate themselves about the environmental factors that influence health. In my experience, the best outcomes often come from integrating the strengths of multiple perspectives. (But encourage you to trust yourself. Do what is right for you.)

Are more healthcare practitioners beginning to learn circadian health?
Yes. Interest in circadian biology is growing among physicians, chiropractors, nutritionists, physical therapists, mental health professionals, health coaches, and many other practitioners. As research continues to expand, more professionals are looking for ways to integrate these principles into the care they already provide. If you are a healthcare practitioner looking to better understand and apply circadian health in your own work, my Mentorship community was created specifically for that purpose.