Hormones fascinate Max Nieuwdorp – so much so that he wrote an entire book about these substances that regulate a wide range of physiological processes, from growth and appetite to falling in love and ageing. Published in 2022 by De Bezige Bij, Wij zijn onze hormonen [We Are Our Hormones] takes readers on a journey through the human body, from conception to death, focusing on the role of hormones. Nieuwdorp draws on examples from his medical practice as well as both recent and distant history. The topic is undoubtedly fascinating, but the reader also comes away with the impression that there’s still a lot we don’t know about hormones.
Interaction
“Absolutely”, Nieuwdorp agrees over Zoom. What is the biggest hormonal mystery he would like to see solved? “How a single hormone can have completely different effects on different people. Take people with an overactive thyroid [which produces hormones that regulate metabolism, among other things]. Most lose weight and feel a bit restless, but I’ve had patients who became psychotic, manic or sexually uninhibited. We still don’t know why an overactive thyroid can cause psychosis in one person while another person experiences hardly any psychological symptoms.” He notes similar variations in menopausal symptoms. “Menopause affects every woman differently. Those differences puzzle me. It’s likely not purely genetic; we suspect that hormones communicate with each other.” But it remains unclear how exactly this interaction works.
Nieuwdorp’s book aims to shed light on these complexities and help people better understand their own bodies. This is urgently needed, he says. What’s the most common misconception he encounters? That everyday stress is caused by an overdose of stress hormones. The opposite is true, explains Nieuwdorp – stress hormones are a response to external triggers. “If you’ve got a fever, your body releases cortisol – a stress hormone – to repair itself. If you’re startled, your body produces adrenaline to help you react.”
Free will
The title of the book, We Are Our Hormones, is a nod to the Dutch bestseller We Are Our Brains by neurobiologist Dick Swaab. Swaab argues that brain processes determine who we are and what we do, which means we don’t have free will. Are we similarly at the mercy of our hormones? Nieuwdorp laughs, shaking his head. No, he says, “I don’t believe everything is predetermined. You won’t hear me deny the existence of free will.” Genetically, we are the product of our ancestors, he explains; our genes provide the foundation for who we are. “On top of that, there’s the influence of hormones, as well as the environment. Your hormones play a role in ‘shaping’ your body, but I believe they’re less important than your genes.”
The Catharina Pijls Lecture will be held on 30 January at 8.00 p.m. in the auditorium of the SBE building at Tongersestraat 53. For registration, please visit maastrichtuniversity.nl/sg.