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.

I hope you enjoy listening.