The Science of Stress: Cortisol, Hormones and Vitamin D with Dr Bronwyn Holmes.
Why chronic stress is a signalling failure rather than adrenal fatigue, and how the right tests reveal what standard blood panels miss.
Dr Bronwyn Holmes explains the science of stress, cortisol, hormones, visceral fat and vitamin D, and how chronic stress affects health, ageing and performance.
In this episode of Podcast Portugal, Justin is joined by Dr Bronwyn Holmes for an in-depth conversation on the molecular biology of stress. Dr Holmes challenges the popular idea of adrenal fatigue, explaining that sustained stress causes the body's receptors to stop responding to cortisol, a signalling failure much like insulin resistance. The hormone is still present, but the message is no longer being received.
The discussion explores why stress is not inherently harmful. Physical and mental stress trigger the same biological response, and controlled exposure, much like progressive overload in training, is essential for growth and resilience. Dr Holmes explains why modern life often lacks the right kind of challenge, and why children and adults alike benefit from tasks that are difficult but achievable.
Dr Holmes also examines how visceral fat, which tends to increase in our forties, behaves as a hormonally active organ, producing its own cortisol and converting hormones into estrogen. She describes how progesterone and estrogen shift with age in both men and women, and why the balance between hormones matters more than any single figure on a blood test.
Vitamin D receives particular attention, not only for bone health but for its role in regulating the stress response and immune function. Dr Holmes shares practical guidance on daily time outdoors and supplementation, and explains why low vitamin D can be a marker of chronic stress rather than simply a deficiency.
Justin and Dr Holmes also discuss the challenge of accessing preventative and hormonal healthcare in Europe compared with the United States. The episode closes with Dr Holmes setting out a more comprehensive, correctly timed approach to testing, including thyroid, insulin, homocysteine, inflammation, sex hormones and cortisol across the day, and why a normal result does not always mean optimal health.
To learn more about Dr Bronwyn Holmes and her work in hormonal and preventative health, visit www.bronwynmd.com
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This episode is for general information only and does not constitute medical advice. Please consult a qualified healthcare professional before making changes to your health, testing or supplementation.