This is a Premium-exclusive episode of the podcast. To listen to the full episode you need to be subscribed to Sigma Nutrition Premium. What exactly are "antioxidants," and why do they get so much hype? We often hear that blueberries, dark chocolate, and red wine are healthy because they're packed with antioxidants – but is the story really as simple as "more antioxidants = better health"? In this episode, Danny explores the true role of antioxidants in the body, challenging simplistic narratives. Are antioxidants magic molecules that single-handedly prevent aging and disease? Or is the reality more nuanced, with context and balance being key? We delve into these intriguing questions to clarify what antioxidants are, how they work, and what the current consensus tells us about using them for health. Antioxidants are frequently credited as the reason why colorful fruits and vegetables are beneficial. Yet, as past Sigma episodes on polyphenols have noted, the benefits of those plant foods aren't primarily due to direct antioxidant effects. Here we untangle common misconceptions (e.g., "antioxidants = health, always"), distinguish between different types of antioxidants, and explain why simply taking high-dose antioxidant supplements isn't a guarantee of protection – and in some cases might even backfire. By the end, health professionals and science-savvy listeners will understand the diverse roles of antioxidants, the importance of balance, and how to apply this knowledge in practice. Timestamps [01:27] Understanding antioxidants [04:19] The role of free radicals [08:43] Endogenous antioxidant systems [09:58] Dietary antioxidants [16:03] Polyphenols and their impact [24:28] Health benefits of polyphenols [27:39] Antioxidants in cognitive function [36:47] Practical takeaways on antioxidants Links & Resources: Subscribe to Sigma Nutrition Premium Go to the episode page Join the Sigma email newsletter for free Become a member of Alan Flanagan's Alinea Nutrition Education Hub Enroll in the next cohort of our Applied Nutrition Literacy course See all our other Recommended Resources Instagram: @sigmanutrition X: @NutritionDanny
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#582: GLP-1 Agonists: Side Effects, Management and Diet – Dr. Spencer Nadolsky
GLP-1 receptor agonists have emerged as a groundbreaking tool in obesity treatment. In this episode, Dr. Spencer Nadolsky (an obesity specialist) explains how these medications are now yielding unprecedented weight loss outcomes in people with obesity. The discussion centers on GLP-1 agonist drugs like semaglutide and tirzepatide: how they work, how much weight loss they can produce, and why they represent a paradigm shift in obesity management. Importantly, the conversation addresses practical aspects of using these drugs, including managing their side effects and optimizing patients' diet and lifestyle while on therapy. This topic is of great significance to nutrition science, clinical practice, and public health. Obesity is a chronic, relapsing condition that has proven difficult to treat with lifestyle changes alone. The advent of GLP-1 agonists offers new hope by inducing weight loss levels previously seen only with surgical interventions. Understanding these medications is crucial for healthcare professionals: it enables evidence-based prescribing, proper patient counseling on diet and side effects, and integration of medication with lifestyle interventions. Discussing safety and long-term use is vital, as millions more patients might use these drugs in coming years. From a public health perspective, GLP-1 agonists prompt debates about access and cost, given their high price and life-changing potential. Timestamps [03:25] Conversation with Dr. Spencer Nadolsky begins [05:24] Mechanism and types of GLP-1 medications [07:55] Efficacy and weight loss results [16:53] Common side effects and management [22:57] Muscle loss concerns and clinical insights [28:09] Addressing nutritional concerns with GLP-1 medications [29:38] Exploring potential benefits beyond weight loss [33:48] Marketing and misconceptions around GLP-1 [36:59] Public health and accessibility issues [43:25] Future research [46:16] Key ideas segment (Premium-only) Related Resources Go to episode page Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Enroll in the next cohort of our Applied Nutrition Literacy course Vineyard – Dr. Nadolsky's Virtual Clinic (US) Instagram: @drnadolsky @sigmanutrition Related episodes: 460: Dr. Priya Sumithran – Body Fat Regulation, Pros & Cons of Weight Loss Interventions, and GLP-1 Receptor Agonists 324: Fatima Cody Stanford, MD – Obesity Treatment & Weight Bias 395: Prof. Carel Le Roux – Current Thinking in Obesity Treatment
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#581: What Is Successful Public Nutrition Policy? And Why Is It So Hard to Achieve? – Emily Callahan, RD, MPH
Public nutrition policy plays a critical role in shaping population health through laws, guidelines, and programs that influence what people eat. In this episode, Emily Callahan, an expert in nutrition policy, talks about why public nutrition policies often fall short and what "success" looks like. They discuss how evidence-based nutrition interventions can stall due to political or practical barriers, and explore examples ranging from federal food assistance programs to sodium reduction initiatives. Crucially, they address how to evaluate if a policy has worked and highlight emerging strategies (like integrating "food as medicine" into healthcare) that offer hope for better outcomes. This conversation is highly relevant for researchers, clinicians, and nutrition professionals, as it underscores the importance of policy in addressing nutrition challenges at the population level and examines how to design effective, data-driven policies for public health impact. Timestamps [05:09] Understanding public health nutrition policy [08:44] Examples of public nutrition policies [21:27] Challenges in implementing nutrition policies [31:24] Evaluating the success of nutrition policies [34:58] Sustainability and political viability of health policies [38:07] Food Is Medicine: a promising policy target [44:50] Medically tailored meals: evidence and implementation [48:55] The MAHA commission report and its implications [56:42] Future directions in nutrition policy [01:04:49] Key ideas segment (premium-only) Related Resources Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Go to episode page Enroll in the next cohort of our Applied Nutrition Literacy course JAMA Commentary: The MAHA Commission Report and Diet-Related Diseases in Youth – Mozaffarian, Callahan & Frist, 2025 Mozafarrian et al., 2024 – "Food Is Medicine" Strategies for Nutrition Security and Cardiometabolic Health Equity: JACC State-of-the-Art Review Tufts' Food Is Medicine Institute
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#580: Sodium Bicarbonate for Sports Performance – Prof. Lewis Gough
Sodium bicarbonate is one of the most consistently supported ergogenic aids in sports nutrition research, yet its underlying mechanisms and real-world applications remain widely misunderstood. More recent developments have focused on how to optimise both the timing and formulation of supplementation. The "individualised ingestion timing" approach has emerged as a practical strategy, recognising that the time-to-peak blood bicarbonate concentration varies considerably between individuals. Similarly, novel formulations are being explored to address issues with gastrointestinal distress and practicality of dosing. These include topical approaches such as sodium bicarbonate lotion, and commercial products like Maurten's "Bicarb System." In this episode, Prof. Lewis Gough joins to discuss the latest evidence on sodium bicarbonate and performance, its mechanisms, novel delivery systems, and the key directions for future research. Dr. Lewis Gough is a Professor of Nutrition and Physiology at Birmingham City University. He is globally recognized for his research on sodium bicarbonate supplementation in sport, and his work spans applied sport and exercise nutrition, exercise metabolism, acid–base balance, and fatigue. Timestamps [03:12] Professor Gough's academic journey [06:29] Mechanisms of sodium bicarbonate and historical perspective on lactate [11:21] Sodium bicarbonate's role in performance [22:45] Individual responses to sodium bicarbonate [26:53] Timing strategies for sodium bicarbonate [32:38] Individualized approach to sodium bicarbonate timing [36:47] Traditional vs. novel delivery methods [44:27] Practical recommendations for athletes [51:18] Future research directions [01:02:08] Key Ideas segment Resources Go to episode page (w/ links to relevant studies) Subscribe to Sigma Nutrition Premium Join the Sigma email newsletter for free Enroll in the next cohort of our Applied Nutrition Literacy course See all of Sigma's "Recommended Resources"
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#579: Is Your Chronotype Hard-Wired or Modifiable? And What Does It Mean for Health?
In this episode, we explore the concept of chronotype, which reflects an individual's biological circadian timing and how it manifests in preferred sleep–wake patterns. Understanding chronotype is important because it differs from simple diurnal preference, which may be shaped by lifestyle or psychological factors rather than biology. We examine how chronotype is measured, from gold-standard laboratory methods to validated questionnaires used in field studies. The discussion also highlights the importance of accounting for sleep debt when estimating true biological timing. Finally, we consider the limitations of consumer devices and the practical implications of assessing chronotype in real-world settings. Timestamps [02:02] Understanding chronotypes [06:26] Measuring chronotypes [15:12] Genetic and environmental influences on chronotypes [28:34] Health implications of chronotypes [52:21] Practical applications Related Resources Join the Sigma email newsletter for free Subscribe to Sigma Nutrition Premium Become a member of Alan Flanagan's Alinea Nutrition Education Hub Enroll in the next cohort of our Applied Nutrition Literacy course Related previous episodes: 495, 470, 469
Discussions about the science of nutrition, dietetics and health. The podcast that educates through nuanced conversations, exploring evidence and cultivating critical thinking. Hosted by Danny Lennon.
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