Dr Rangan Chatterjee

Fastest Way To Decreased Lifespan – & You’re Doing It Daily! (Prevent Disease With This One Habit)

This episode is brought to you by: BON CHARGE: Save 20% off with code LIVEMORE https://boncharge.com/livemore Download my FREE Sleep Guide HERE: https://bit.ly/3OzqCap When we think of sunlight, vitamin D is usually the first thing that comes to mind. But the truth is, the full spectrum of light that we get exposed to when we spend time outside plays a vital role in how we sleep, how we feel and even how our cells create energy. This week’s returning guest is Dr Roger Seheult, who believes that sunlight is one of the most accessible and underutilised tools we have for improving health – and the science he shares is compelling. I’m delighted to welcome back to my Feel Better, Live More podcast for our third conversation. Roger is a quadruple board-certified physician in Internal Medicine, Pulmonary Diseases, Critical Care and Sleep Medicine. He is also an Associate Clinical Professor at the University of California, Riverside, and Assistant Clinical Professor at Loma Linda University. Alongside his clinical practice, he co-founded MedCram, a medical education platform with over one million YouTube subscribers, widely used by hospitals and medical schools worldwide. Roger is also a sought-after lecturer and has received multiple awards for his contributions to medicine and education. His passion lies in making complex medical science accessible, and he regularly lectures to schools, hospitals and media outlets. In this conversation, we discuss: ● Why deficiency in sunlight can show up as fatigue, poor sleep, inflammation or even raised cholesterol. ● The three “macronutrients” of light – visible, ultraviolet and infrared – and how each plays a different role in mood, immunity and cellular energy. ● How infrared light penetrates deep into the body, supporting mitochondrial function and how it may help protect against diseases such as diabetes and dementia. ● Why spending 15–20 minutes a day outside – even in the shade – can be enough to recharge our cells. ● The growing evidence that sunlight exposure lowers the risk of all-cause mortality, cancer and heart disease. ● Practical strategies for getting the benefits of sunlight safely, even if you live in colder climates or spend much of your day indoors. Roger also shares his “eight laws of health” – simple, timeless principles that include nutrition, rest, fresh air and sunlight – and explains how neglecting them leads to the chronic conditions he often sees in his work in intensive care. This is a fascinating conversation that will change how you think about sunlight. It isn’t just something that makes us feel good – it’s a fundamental part of how our bodies stay healthy. And the best part? It’s free and available to us all. #feelbetterlivemore ---- Connect with Roger: Website https://medcram.com https://instagram.com/medcram/ https://twitter.com/rogerseheult https://youtube.com/channel/UCG-iSMVtWbbwDDXgXXypARQ #feelbetterlivemore #feelbetterlivemorepodcast ------- Order MAKE CHANGE THAT LASTS. US & Canada version https://amzn.to/3RyO3SL, UK version https://amzn.to/3Kt5rUK ----- Follow Dr Chatterjee at: Website: https://drchatterjee.com/ Facebook: https://www.facebook.com/drchatterjee Twitter: https://twitter.com/drchatterjeeuk Instagram: https://www.instagram.com/drchatterjee/ Newsletter: https://drchatterjee.com/subscription DISCLAIMER: The content in the podcast and on this webpage is not intended to constitute or be a substitute for professional medical advice, diagnosis, or treatment. Never disregard professional medical advice or delay in seeking it because of something you have heard on the podcast or on my website.

RCDr. Rangan Chatterjeehost

Oct 15, 2025·1h 57m·Watch on YouTube ↗

📖 CHAPTERS

1. 1

   How sunlight deficiency can show up in the body

   The conversation opens by exploring how a lack of sunlight can manifest as broad, non-specific symptoms—and why the stakes may be much higher than most people realize. Dr. Seheult frames sunlight as a low-effort intervention with potential effects on mortality and multiple disease categories.

2. 2

   Why modern life deprioritized sunlight (and why older hospitals didn’t)

   They contrast modern indoor living with historical approaches to healing, when buildings and hospitals were intentionally designed to maximize fresh air and direct sunlight. Florence Nightingale is cited as an early clinical observer of light’s therapeutic value.

3. 3

   Making “invisible” light visible: infrared photography and indoor light poverty

   Dr. Seheult describes a smartphone filter that converts infrared into visible light, revealing how little infrared reaches us indoors. This segment highlights how modern homes and windows dramatically reduce biologically relevant wavelengths—especially given how much time people spend inside.

4. 4

   The “macronutrients of light”: visible, UV, and infrared

   They propose a simple framework: light has distinct “nutrients,” each with different biological roles. Visible light affects mood and circadian timing, UVB supports vitamin D production, and infrared penetrates deeply and may influence cellular energy systems.

5. 5

   Infrared physics: penetration, clouds, clothing, and tree reflection

   They dig into why infrared matters: it penetrates far more deeply than most people assume and can pass through clothing. Cloud cover reduces infrared somewhat, but leafy environments reflect infrared strongly—meaning outdoor shade can still provide meaningful exposure.

6. 6

   What infrared is doing: mitochondria, aging, and vision improvements

   This chapter connects infrared exposure to mitochondrial performance—the cellular energy system implicated in many chronic conditions and aging. Dr. Seheult explains research showing measurable improvements in visual function after near-infrared exposure, tying it to energy output in retinal cells.

7. 7

   The “low-battery human” analogy and disease links to mitochondrial dysfunction

   Dr. Chatterjee compares sunlight/infrared exposure to charging a phone—suggesting many people live in a chronically “low power mode.” They link mitochondrial dysfunction to obesity, insulin resistance, dementia, cardiovascular disease, inflammation, and long COVID, reinforcing why light could be foundational.

8. 8

   How much exposure is needed: biphasic dosing and realistic daily targets

   They address a key barrier: people assume they need hours of sun. The discussion emphasizes brief, consistent exposure (often minutes) and describes a biphasic response—after a point, more light brings diminishing returns.

9. 9

   Sunlight vs red-light panels: when devices help (and when they’re a poor substitute)

   Red-light panels and bulbs are treated as tools, especially in winter or for those unable to get outdoors. Evidence is discussed showing benefits in low-sun months, and even improvements from adding incandescent sources in LED-lit offices—supporting the idea that modern lighting is missing key wavelengths.

10. 10

    Light through windows, low‑E glass, and why “near the window” used to matter more

    They explore why windows sometimes help and sometimes don’t. Older hospital findings (faster discharge near windows) may not translate to modern low‑E glass that blocks infrared to improve energy efficiency, potentially creating unintended health trade-offs.

11. 11

    A balanced view of sun exposure: mortality benefits vs melanoma risk, plus ‘solar rhythm’ protection

    They review large population data (UK Biobank and other cohorts) linking higher solar exposure with lower all-cause, cardiovascular, and cancer mortality, without a clear dramatic melanoma signal at the population level. They also describe how the natural daily spectrum (IR-rich mornings/evenings, UV-rich midday) may offer built-in protection via melatonin and antioxidant dynamics.

12. 12

    LED lighting and screens: the modern spectral mismatch (and ecological ripple effects)

    This chapter explains how LED lighting concentrates on visible wavelengths while stripping infrared that humans historically received from fire, candles, and incandescent bulbs. They also discuss why screens and bright light at night disrupt circadian biology—and even mention unintended impacts on urban plant/insect ecosystems.

13. 13

    Bright nights vs dark nights: mortality data, shift work strategies, and timing food intake

    They unpack evidence showing light is beneficial during the day but harmful when it peaks late at night, including large-scale wearable light-sensor research. Practical tactics are given for night-shift workers (dimming light, controlling sleep darkness) and emerging evidence suggests avoiding eating at night may reduce metabolic harm.

14. 14

    Practical protocol: morning outdoor light, SAD boxes, and evening light discipline

    They consolidate actionable steps: get outside daily (ideally in the morning) for visible light/circadian benefits plus infrared exposure, use SAD boxes strategically when needed, and dramatically reduce bright/overhead light at night. Short-term metabolic improvements are cited, along with seasonal mortality patterns to reinforce urgency ahead of winter.

15. 15

    Nature as medicine: the Green Heart Project tree-planting study and inflammation reduction

    They close by highlighting evidence that greener environments improve health beyond socioeconomic confounding. The Louisville Green Heart Project is presented as a natural experiment: adding thousands of mature trees was associated with meaningful reductions in inflammatory markers, potentially via increased outdoor time, phytoncides, and infrared-rich environments.