Sunlight Matters

In this insightful podcast discussion, friend of the podcast, Professor Glen Jeffery, sheds light on his recent study published in Nature (https://www.nature.com/articles/s41598-026-35389-6)

Introduction
In a world dominated by LED lighting, we often overlook its potential health consequences. Professor Glen Jeffery's groundbreaking study highlights the significant effects of artificial lighting on our vision and overall metabolic health.

The Research Background
Professor Jeffery begins by addressing growing concerns about how artificial lighting affects our health, particularly in environments with scarce natural light. The study was conducted in a building at University College London. The hypothesis was that the lack of natural light and the prevalence of LED lighting could be detrimental to overall health, particularly in terms of colour perception and metabolic functions.

The Experiment
The unique aspect of this study was its real-world setting. Instead of a controlled laboratory, the researchers chose an office environment where participants would typically work. Participants were given old incandescent light bulbs, which emit a broader spectrum of light, including infrared, crucial for metabolic health.

Surprising Results
The results were striking: participants showed a highly significant improvement in their vision after only a short exposure to incandescent lighting. This improvement persisted for months after the bulbs were removed, suggesting that exposure to a broader spectrum of light is vital for visual and metabolic health. Professor Jeffery emphasised that this study is a wake-up call about the damaging effects of LED lights, which may suppress our physiological functions, including colour vision.

The Importance of a Balanced Light Spectrum
Professor Jeffery highlighted that while LED lighting is often considered energy-efficient, it poses risks to human health by limiting the spectrum of light we are exposed to. He discussed the need for architects and lighting engineers to rethink building design, emphasising the importance of incorporating a wider spectrum of light for optimal health. The study also raised concerns about the glass materials used in buildings, which block essential infrared light.

Moving Forward: Practical Solutions
To address these challenges, Professor Jeffery suggests we don’t need to eliminate LEDs entirely. Instead, he advocates a balanced approach to lighting by integrating incandescent bulbs into our environments. Simple measures, such as using incandescent bulbs with dimmer switches, can mitigate the negative effects of LED lighting. He also urges policymakers to rethink regulations surrounding incandescent bulbs to ensure a healthier future.

Key Takeaways

1. LED lighting may impair our vision and metabolic health.
2. Exposure to incandescent bulbs can significantly improve colour perception and overall well-being.
3. A balanced approach to lighting, incorporating a variety of light sources, is essential for our health.
4. Policymakers must prioritise health implications when designing lighting regulations.

The paper is available for download here: https://www.nature.com/articles/s41598-026-35389-6

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

In this episode of Sunlight Matters, Dave sits down with the brilliant Paula Longato—architect, daylight consultant, and lighting designer—to explore why daylight access and sunlight analysis are critical yet often overlooked elements in urban design and architecture.

🎙️ What You'll Learn:

• Why modern cities like New York and Dubai are "dark daylight cities" 🌆
• The role of shadow mapping and solar exposure in creating healthier urban environments
• How real estate sun studies can shape better buildings and energy-efficient homes
• The silent power of green light, and how vegetation affects our mental and physical health 🌿
• Why vernacular architecture holds the key to future-ready, climate-conscious cities
• The untapped potential of darkness design and the physiological dangers of over-illumination 🌒

💡 Paula shares her journey from sun-soaked São Paulo to the grey skies of Germany—and how that shift sparked a lifelong passion for daylight architecture and sunlight-responsive urban planning. Together, they tackle the complexities of building orientation, facade engineering, and circadian lighting, offering a holistic view of how we can—and must—build better with the sun in mind.

🌇 Whether you're an architect, city planner, homebuyer, or just someone chasing sunlight, this episode will shift the way you think about the built environment and your place within it.

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

Dave sits down with Ulysse Dormoy, CEO of Atrium Ltd, to explore a subject hiding in plain sight: the light we live under every day — and how it’s quietly impacting our health, performance, and wellbeing 🌞🏙️

What starts as a conversation about lighting design quickly reveals a much bigger story. From LED flicker and infrared deprivation, to the shocking parallels between ultra-processed food and ultra-processed light, Ulysse shares his journey into the world of light as a biological force.

We dive into:
 🔎 How modern offices and homes are robbing us of essential light
 🌿 Why sunlight exposure, shadow mapping, and solar orientation matter more than ever
🧠 The science behind photobiomodulation and its rising popularity
🏢 The silent health risks baked into energy-efficient architecture
🚶‍♂️ What designers, planners, and employers can do to build truly healthy environments

You’ll also hear why Ulysse carries a spectrometer everywhere, what happens when beauty brands get lighting wrong, and how we might be heading towards a "lighting tobacco moment" — where health meets accountability ⚠️

Whether you're an architect, designer, developer, or just spend too much time indoors, this episode will change the way you think about light, space, and health forever 🌇

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

What if everything you thought you knew about sunlight was just scratching the surface? ☀️🔬

In this illuminating episode of Sunlight Matters, hosts Dave and Georg sit down with world-renowned astrophysicist Dr. Bob Fosbury — a former senior scientist with the European Space Agency, key contributor to both the Hubble and James Webb Space Telescopes 🔭, and a trailblazer at the intersection of astronomy, biology, and human health.

🌌 From black holes and the Big Bang to mitochondria and macular degeneration, Bob connects the dots between cosmic light and cellular life in a way that’s as profound as it is practical. This is not just science — this is a blueprint for how to live in harmony with the energy source that powers everything on Earth: the Sun. 

🎙️ Together we explore how infrared light, once overlooked, is now recognized as vital for metabolism, ageing, mitochondrial health, and even mental clarity. You’ll understand why modern architecture, LED lighting, and indoor living might be depriving us of essential solar wavelengths — and what steps we can take to reconnect with full-spectrum sunlight in our homes, cities, and everyday lives. 

☀️ In This Wide-Ranging Episode, We Cover:

• 🌌 The origins of light — and how it shaped the universe
• 🌱 How photosynthesis and metabolism mirror the thermodynamics of stars
• 🧬 The role of infrared light in mitochondrial function and ATP production
• 🚨 Why white LED lights may be disrupting human biology and increasing disease risk
• 🏢 How urban planning, window glass, and building design limit natural solar exposure
• 🧠 How entropy, aging, and light are intimately connected
• 🧭 Why understanding the energy flow of life can help us build healthier, more sustainable systems
• 🌞 The future of sunlight-based health interventions, lighting design, and planetary living

Whether you're a curious mind, an architect, a real estate professional, a health practitioner, or someone exploring the science of sunlight for personal vitality, this episode offers new frameworks, ancient truths, and practical insights. You’ll never view the Sun (or your indoor lights) the same way again. 

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

In this companion episode to the Roger Seheult episode, Dave is joined by three experts—Prof. Glen Jeffery, Scott Zimmerman, and Dr. Bob Fosbury—to explore how sunlight and infrared light influence human health, particularly in the darker months when Seasonal Affective Disorder (SAD) becomes more prevalent.

Dave opens up about his own experience with SAD, leading to a wide-ranging discussion of how modern indoor lighting, architecture, and urban planning fail to meet the biological needs shaped by our evolution under the sun.

☀️ Key Topics Covered:

🌤️ 1. Sunlight, Metabolism & Infrared Light

• Sunlight isn’t just about visible light; it’s packed with near and mid-infrared radiation that helps us metabolize food more efficiently.
• Buildings and LED lighting systems block this critical part of the light spectrum, leaving our bodies in a state of "metabolic darkness."
• Even on cloudy days and in indirect light, infrared exposure still provides meaningful benefits.

🧬 2. The Mitochondrial Connection

• Mitochondria, our cells' energy centers, thrive in infrared-rich environments.
• There’s compelling evidence suggesting that light exposure, especially infrared, directly influences aging, energy levels, and immunity.

🏡 3. Indoor Light vs Outdoor Light

• Modern architecture prioritizes energy efficiency (e.g., LED lighting and infrared-reflective glass), but at a steep cost to human health.
• Real estate sun studies and shadow mapping in urban design must now account for solar exposure and infrared access, especially in northern latitudes.

💡 4. Incandescent vs. LED Light Debate

• All three experts agree: incandescent bulbs are far superior to modern LEDs in terms of health benefits because they emit full-spectrum, thermal light—including infrared.
• LEDs emit light for vision, not for life. This has triggered a global metabolic health crisis, especially in developed nations.

🔥 5. Practical Tips to Survive Winter

• Use incandescent bulbs indoors with dimmers (e.g., oven or heat lamp bulbs).
• Spend time outside daily, even if it's cloudy—clouds reflect valuable infrared.
• Install a small outdoor sun shelter or plastic greenhouse to maximize sun exposure.
• Use a fireplace or candles to reintroduce thermal light into the home.
• Saunas also provide therapeutic benefits through infrared exposure and vasodilation.
• Reconsider the window design, indoor layout, and lighting strategy to optimize natural light orientation.

🌎 Broader Implications:

The discussion highlights how our evolutionary biology is deeply tied to the solar spectrum, yet modern society is stripping us of this essential relationship. There’s a pressing need for policy changes around building codes, indoor lighting regulations, and environmental design to restore sunlight accessibility in our daily lives.

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

As winter approaches in the North, the days get shorter, the skies darker, and for many of us, our energy, mood, and health start to dip. In Part 1 of a 2-part special of Sunlight Matters, Dr Roger Seheult joins Dave and Georg to share science-backed tips to help you stay healthy, energized, and resilient through the long winter nights.

From understanding the hidden power of infrared light to simple daily routines that boost your immune system and mood, this episode is packed with practical advice for winter wellness—even when it’s cold, cloudy, and grey.

🌟 What You’ll Learn:

• Why spending just 15–20 minutes outdoors (even in cloud cover) can boost your mitochondria and mood
• How to make your indoor environment healthier using incandescent bulbs or even a simple fireplace
• What types of clothing still let infrared light through—and why that matters in winter
• The truth about vitamin D, UV exposure, and whether supplements or food sources are enough
• City dwellers: how to find hidden patches of winter sun between buildings and trees
• The surprising benefits of saunas, cold plunges, and honoring your body’s slower winter rhythm
• Why old wisdom—like afternoon walks and letting in sunlight—might be good for us

☀️ This episode is all about resetting your relationship with winter—with strategies that cost little or nothing but make a big difference. Whether you're fighting the winter blues, looking to boost your energy, or just want to stay well, these are the seasonal habits your body has been craving.

📲 Listen now and build your personal toolkit for surviving (and even enjoying) the darker months ahead.

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

In this thought-provoking episode of Sunlight Matters, we travel across Europe to explore how daylight access, sunlight rights, and urban densification intersect—and often clash.

Joining us are three brilliant minds working at the forefront of daylight analysis and sunlight legislation:

🌞 Mina Gaarder – A Civil Engineer based in Norway who recently completed a master’s thesis on daylight in dense urban areas, comparing regulatory frameworks in Norway, Sweden, the UK, and the U.S. She brings a research-driven lens to how daylight affects housing quality, health, and urban form.

🌞 Susanne Höglin – Stockholm-based building permit architect and former case manager at Stockholm Municipality. Now working at ACC Glas och Fasadkonsult, she investigates how urban densification affects daylight access in existing buildings and how legislation is keeping pace (or not).

🌞 Eftychia Stamataki – Architect and energy-efficient buildings expert, originally from Greece and now based in Stockholm. At ACC Glas och Fasadkonsult, she leads projects on daylight and sunlight studies, as well as thermal comfort, and advocates for the better integration of sunlight in early-stage urban design.

Together, we unpack:

• 🌇 The difference between daylight and sunlight—and why it matters
• 🏙️ How shadow mapping tools like Shadowmap empower citizens to challenge poor planning
• ⚖️ Why laws protecting existing building light access missing or weak in many countries
• 📐 How older urban codes used geometry to protect sunlight—and what we’ve lost in the digital age
• 🗣️ Why public education and democratization of urban design are vital to fair development

If you're interested in sunlight analysis, urban planning best practices, or want to understand how sun exposure impacts health and housing quality, this episode is for you.

🔦 Don’t miss this deep dive into the bright side of building cities better.

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

In this episode, we are joined by David Herrera, better known online as The Solar Athlete, who brings a unique blend of engineering, biology, and real-world coaching to the conversation. 

From his backyard in high-altitude Wyoming, David shares the incredible journey that took him from world-class powerlifter and oilfield technician to a leading voice on circadian biology, light hygiene, and solar optimization for human performance.

In this episode, we dive into:

☀️ Why sunlight exposure is the most overlooked tool for boosting vitality, performance, and sleep quality
🌡️ How cold and solar exposure work together to regulate metabolism, brain function, and melanin repair
📶 What happens when you're living next to a cell tower, and why EMF awareness is critical to long-term health
🏠 The role of melanin as a biological semiconductor — and how to use it like solar tech for your body
🧊 Simple, science-backed winter protocols to stay tuned to natural rhythms — including outdoor exposure, infrared light, and the surprising benefits of staying cold
💡 Practical strategies for working with — not against — the seasons using light, timing, and indoor environment tweaks
🏙️ And why sunlight analysis, shadow mapping, and smart home orientation should be a priority in architecture, urban planning, and real estate design

Whether you’re an athlete, architect, health hacker, or someone trying to shake off the winter blues, this is your blueprint for living in alignment with the original energy source of life: the Sun.

🔥 Tune in and discover how to create your own seasonal protocol, master light exposure, and reclaim the natural intelligence of your biology, One Sunrise at a Time.

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

What if your computer screen could heal you instead of harming you?

In this episode of Sunlight Matters, we’re joined by Dr Peter Veto and Liliana Lettieri, the visionary team behind Pixun — a company pioneering solar-powered, full-spectrum displays that use real sunlight instead of artificial backlighting.

Peter and Liliana share their personal journeys with light sensitivity, screen-induced insomnia, and EMF-related health issues, and how those struggles inspired them to engineer a radically new type of screen — one that brings the entire solar spectrum indoors using fiber  optics and rooftop solar collectors.

We dive into:

• Why most screens today are making us tired, sick, and unfocused
• The science behind sunlight exposure, blue light toxicity, and circadian disruption
• How Pixun’s screens deliver natural light through displays, supporting everything from sleep health to vision and cellular function
• Real-world applications for urban living, real estate sun studies, architecture, and workspace wellness
• How tools like shadow mapping and sunlight analysis can optimize solar collector placement for homes and commercial buildings

Whether you’re a parent worried about your child’s screen time, an architect exploring better building orientation, or a company looking to improve employee wellness through sunlight-optimized tech — this episode will change the way you think about screens forever.

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.

In this powerful and eye-opening episode, Dave speaks with Theresa Bug, a former German police officer turned online health coach, holistic nutritionist, and advocate for natural light, grounding, and mitochondrial health.

🌿 Theresa shares her inspiring journey from a high-stress career in law enforcement—across Paris, London, Israel, and Africa—to deep healing through sunlight exposure, circadian rhythm restoration, and reconnecting with nature. Her story is a testament to the life-changing power of simple yet profound lifestyle changes.

💡 Key Topics Covered:

• How chronic stress and PTSD led her to holistic health
• The science behind morning sunlight and mitochondrial function
• Why grounding (earthing) and going barefoot can reset your nervous system
• The truth about blue light, screen time, and modern lighting
• The problems with supplement culture vs. real food and lifestyle
• How to eat seasonally and locally for optimal health and gut function
• Why gyms might be harming us more than helping—and how to exercise in harmony with nature
• Insights into raw milk, hydration, EMFs, red light, sleep, and ancestral living

☀️ This conversation explores how sunlight analysis, circadian health, and shadow-free living can transform your physical and mental health—especially in a world of artificial light, disconnected routines, and overprescribed medications.

To find out more about Theresa, her Website is a great starting point:

 https://www.theresabug.com/home

or 

Linkedin: https://www.linkedin.com/in/theresa-christinerangebased/

Sunlight Matters is a podcast that explores the Sun's role in human health, architecture, cities, and everyday life.

Through conversations with scientists, architects, and technologists, the series examines how natural light shapes our bodies, our buildings, and how we live indoors.

Hosted by Dave Wallace, Sunlight Matters asks a simple but overlooked question: what happens when we disconnect from the Sun?

Because sunlight isn’t optional. It matters.

Please like and subscribe.

Disclaimer: Sunlight Matters is for information and general interest only. Nothing discussed on the podcast should be taken directly as medical, architectural or other professional advice.