Sigma Nutrition Radio
The podcast for lovers of nutrition science! Listen to detailed discussions with researchers and leading experts about the science of nutrition, dietetics and health.
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#544: Genetic Variants and Response to Nutrients – Martin Kohlmeier, MD PhD
11/26/2024
#544: Genetic Variants and Response to Nutrients – Martin Kohlmeier, MD PhD
In the realm of nutrition science, individual differences are more profound and impactful than many realize. For decades, we’ve developed dietary recommendations with a “one-size-fits-all” approach, assuming that most people respond similarly to specific nutrients. But Dr. Martin Kohlmeier, a pioneer in precision nutrition, challenges this very notion. How might an individual’s genetic makeup alter their need for certain nutrients? With advances in nutrigenetics, we’re beginning to see how personalized nutrition could bridge long-standing gaps in dietary efficacy. Dr. Kohlmeier’s work highlights fascinating examples, from the APOE4 gene’s influence on cholesterol metabolism to variations in folate metabolism that could affect everything from heart health to birth outcomes. As Dr. Kohlmeier explains, precision nutrition is not simply about adding genetic testing to a wellness regimen. Instead, it requires rethinking nutrition research from the ground up—ensuring studies capture these individual variations and that public health policy moves beyond broad averages. With genetic testing now more accessible than ever, could commercial pressures and oversimplified testing derail the science before it even gets going? In this episode, we dive deep into the potential and pitfalls of precision nutrition, exploring the future of personalized dietary advice and the road to truly individualized health. Timestamps [02:33] Introduction of Dr. Martin Kohlmeier and his background [05:10] Rethinking assumptions in nutrition science [07:42] The role of genetic variations in nutrient responses [13:15] Practical examples of genetic impact on nutrition [22:55] Misinformation and commercial misuse in nutrigenetics [29:48] Case studies: cholesterol sensitivity (APOE4) and folate metabolism (MTHFR) [41:03] Public health implications and the need for tailored research [49:27] Future directions and the path forward for precision nutrition Links Go to Join the for free Subscribe to Enroll in the next cohort of our course Kohlmeier, 2023 –
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Some deals on evidence-based resources
11/25/2024
Some deals on evidence-based resources
- Come join us! Get 20% off all subscription options. - The best online database for looking at the evidence of foods, nutrients, supplements and health outcomes just got revamped. - Get 30% off their breakdowns of the latest training and nutrition research for strength trainees. - Get Alan's deepdive analysis of methodology and study interpretation.
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#543: Eye Health & Nutrition – Prof. John Nolan
11/19/2024
#543: Eye Health & Nutrition – Prof. John Nolan
In this episode, we dive deep into the world of ocular nutrition with Professor John Nolan, exploring how specific nutrients can play crucial roles in preserving eye health, improving vision and supporting cognitive function. With age-related macular degeneration (AMD) affecting millions globally, Professor Nolan sheds light on groundbreaking research showing how certain carotenoids—natural pigments found in plant foods—could impact eye health and perhaps even neurodegenerative conditions like Alzheimer’s disease. But what are these compounds exactly, and why are they so impactful? Through in-depth clinical studies, Nolan has identified optimal nutrient formulations that could bridge the gap in conditions as diverse as macular degeneration and cognitive decline. He makes a compelling case for why the timing and quality of these interventions could matter as much as diet itself. Finally, this episode goes beyond individual health to consider public health implications, particularly the need for better regulation in the supplement industry and enhanced nutritional education for medical practitioners. Timestamps [01:20] Professor Nolan’s academic journey and early inspirations in vision science [02:12] Groundbreaking research on age-related macular degeneration (AMD) [04:24] How carotenoids contribute to eye health and disease prevention [07:27] Expanding from eye research to exploring brain health connections [16:23] Overcoming challenges in developing effective nutritional supplements [20:57] The role of preventative nutrition in eye and cognitive health [27:28] Key findings from major human trials on carotenoids and vision [33:37] Evidence linking carotenoids to cognitive health and aging [42:53] Practical insights for medical practitioners on using nutrition for eye health Links: Go to Join the for free Subscribe to Enroll in the next cohort of our course Caretenoid supplement mentioned by Prof. Nolan:
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#542: Nutrients for Cognitive Performance in Sports – Prof. Shawn Arent, PhD
11/12/2024
#542: Nutrients for Cognitive Performance in Sports – Prof. Shawn Arent, PhD
In the world of sports nutrition, understanding how different supplements and nutrients impact not just physical performance but also cognitive function is rapidly gaining traction. Athletes are constantly seeking that competitive edge, and while many are familiar with the benefits of carbohydrates and caffeine for energy and focus, there’s much more at play. Emerging research is highlighting the roles of compounds like creatine and omega-3s, not only for muscle recovery but also for brain health, particularly following traumatic brain injuries (TBI). Beyond the usual suspects of performance nutrition, intriguing compounds like theacrine and tyrosine are entering the conversation. With potential cognitive effects that range from improved focus to faster decision-making, these supplements have sparked interest but also raise questions. How strong is the evidence behind these claims, and where do we draw the line between scientific promise and practical application? How do we apply the science in real-world settings where perfect data may not exist? This episode addresses these questions via the insights of Professor Shawn Arent of University of South Carolina. Timestamps 01:44 – Dr. Arent’s key areas of research 04:03 – Defining and understanding cognitive performance in athletes 09:31 – The impact of carbohydrates on cognitive function and decision-making 29:00 – Protein, amino acids, and their role in cognitive function under stress 34:17 – How caffeine enhances cognitive performance: decision-making and reaction time 42:00 – Comparing the effects of theacrine and caffeine on cognitive and physical performance 44:48 – How caffeine dosing impacts sleep and recovery 46:55 – Theacrine, dynamine, and emerging supplements in sports performance 57:56 – Nicotine’s potential cognitive benefits and the associated risks for athletes 01:04:56 – Creatine and omega-3s: their roles in brain health and concussion recovery 01:13:05 – Navigating the challenges of applying research to real-world practice Links: Go to Join the for free Subscribe to Enroll in the next cohort of our course Get and collegues
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#541: Lean Mass Hyper Responders & the Lipid Energy Model: Do the Claims Stand Up to Scrutiny?
11/05/2024
#541: Lean Mass Hyper Responders & the Lipid Energy Model: Do the Claims Stand Up to Scrutiny?
When discussing cardiovascular health, few topics stir as much debate as cholesterol, particularly in relation to low-carb and ketogenic diets. Recently, there’s been significant attention given to a proposed model that suggests high LDL cholesterol may not pose the same cardiovascular risk in certain individuals, specifically those labeled as “lean mass hyper-responders.” This raises important questions: Is it possible that high cholesterol might not be dangerous for everyone? Or are we witnessing a dangerous misinterpretation of the science? In this episode, we break down the ideas behind the “lipid energy model” and explore how it has been framed in the context of low-carbohydrate and ketogenic diets. While proponents claim this model sheds light on how some people can have elevated LDL without increasing heart disease risk, critics warn that miscommunication and oversimplification of these ideas are leading many down a dangerous path. With real-world health decisions hanging in the balance, it’s crucial to carefully examine what the science truly says about cholesterol, inflammation, and heart disease. Join us as we dive into the evidence with Dr. Gary McGowan. We’ll dissect what the current research supports, what remains speculative, and how social media has amplified both the promising and problematic aspects of this model. If you’ve ever wondered about the impact of high cholesterol on heart disease risk in the context of ketogenic or low-carb diets, this episode is essential listening. Timestamps 02:27 What are the “Lean Mass Hyper Responder” phenotype and the “Lipid Energy Model” 27:29 Looking at recent publications and the “KETO Trial” 47:06 Public communication and misinterpretation 51:18 Clinical implications of diet-induced dyslipidemia 55:14 Responsibility in scientific communication 57:30 Real-world examples of poor communication or misinterpretation 01:13:27 Ethical concerns with the promotion of the model 01:25:59 Final thoughts Related Resources Go to Join the for free Subscribe to Enroll in the next cohort of our course Find Dr. McGowan at: Papers discussed in this episode:
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Fasting for Health: What Do We Know? (SNP34)
10/29/2024
Fasting for Health: What Do We Know? (SNP34)
Fasting has gained immense popularity as a dietary approach, but what does the scientific evidence say about its health benefits? Studies have explored how fasting might influence metabolic markers, energy expenditure, and even aging. However, while fasting shows promise in some animal models, translating these effects to humans is less clear. A key part of the debate centers on whether fasting offers unique health advantages or whether its benefits stem primarily from reduced calorie intake. Time-restricted eating and intermittent fasting protocols show promise in regulating appetite and reducing energy intake, potentially leading to weight loss. But, when calories are controlled, does fasting still improve health independently? This episode explores the evidence to determine if fasting confers metabolic advantages over non-fasting diets. In addition, we’ll take a look at its impact on behavioral patterns and ask if that could play a pivotal role in promoting better health outcomes. To listen to this episode in full, subscribe to . Timestamps: [00:54] Defining fasting [03:44] Historical context and early research [08:01] Mechanisms and claims of fasting [18:15] Types of fasting protocols [22:18] Time-restricted eating and chronobiology [28:29] Energy expenditure and behavioral changes [36:53] Fasting vs. weight loss: independent benefits [41:47] Health markers and weight loss outcomes [43:37] Muscle mass concerns during fasting [47:31] Animal models vs. human studies [51:29] InterFAST study insights [01:00:37] Behavioral vs. metabolic changes [01:11:25] So what do we know? Links: Subscribe to Join the for free Enroll in the next cohort of our course Go to the
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#540: How Can We Improve Body Image and Self-Esteem Without Physique Change? – Gabrielle Fundaro, PhD & Eric Trexler, PhD
10/22/2024
#540: How Can We Improve Body Image and Self-Esteem Without Physique Change? – Gabrielle Fundaro, PhD & Eric Trexler, PhD
Body image and self-worth are deeply intertwined concepts that influence how we see ourselves and interact with the world. Many people believe that changing their physique is the key to improving their body image, but is it really that simple? This connection between appearance and self-esteem raises important questions about how we define confidence and whether our sense of worth should be tied to how we look. Our relationship with food plays a crucial role in how we view ourselves. While some see food as fuel, others attach much more significance to their eating habits, often linking dietary choices to discipline, success, or failure. But what happens when these beliefs become too rigid? Understanding how our perceptions of food and body image are shaped is essential for navigating the balance between health, happiness, and personal fulfillment. Physique change, often seen as a positive goal, can bring about unexpected psychological impacts. Pursuing a leaner or more muscular body might boost temporary feelings of confidence, but could it also reinforce negative patterns of thought? In an episode co-hosted with Dr. Eric Trexler, Danny talks with Dr. Gabrielle Fundaro in order to tackle some of these concepts and questions. Timestamps: [04:54] Start of conversation [06:40] Defining body image and self esteem [12:26] Relationship with food and weight controllability beliefs [20:38] Impact of body composition on body image [27:40] Challenges in changing body image perceptions [34:43] Influence of coaches on client body image [41:57] Screening for disordered eating [51:50] Ethical responsibilities of fitness professionals [54:53] Improving body image without physique change [61:02] Key ideas segment (premium-only) Links: Get more of Dr. Trexler’s research analysis with the Related previous episodes: See episodes 484 and 367
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#539: How Does Carbohydrate Availability Impact Resistance Training? – Cliff Harvey, PhD & Eric Helms, PhD
10/15/2024
#539: How Does Carbohydrate Availability Impact Resistance Training? – Cliff Harvey, PhD & Eric Helms, PhD
Some suggest that, since individual lifts or short-duration efforts don’t rely heavily on glycogen, carb intake might not be critical for strength athletes. If glycogen depletion isn’t a pressing issue, could athletes thrive on lower-carb diets without sacrificing performance? Or could there be overlooked benefits to having greater carbohydrate availablily in those sessions? In strength sports and resistance training, do carbohydrates play an important role or not? Are carbohydrates really necessary for resistance training? How does training volume, intensity and goals impact the carbohydrate requirement? In this episode, Dr. Cliff Harvey and Dr. Eric Helms offer their perspectives on this interesting and practically important issue. Timestamps: [00:03:40] Do carbohydrates have a role in resistance training? [00:12:23] Do individuals respond differently? [00:18:25] Recent research insights [00:35:08] Carbohydrate “sensing” and performance [00:47:17] How to think about carbohydrate needs [00:54:06] Changing views on nutrient timing [01:06:37] Ketogenic diets and muscle gain [01:22:02] Dietary patterns and health – Are macronutrients that important? [01:31:42] Key ideas segment (Premium-only) Links: for study notes and transcript Join the waitlist for our course Get more of Dr. Helm’s research analysis with the
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#538: Can Fish Oil Supplementation Increase Risk of Irregular Heart Rhythms?
10/08/2024
#538: Can Fish Oil Supplementation Increase Risk of Irregular Heart Rhythms?
Omega-3 fatty acids are often viewed as beneficial or, at worst, neutral supplements when it comes to supporting cardiovascular health, lowering triglycerides, and offering anti-inflammatory effects. Much of the focus in recent years has centered on understanding how significant these benefits are, particularly for heart health, with many studies highlighting the potential for omega-3s to play a positive role in reducing cardiovascular risk. However, an emerging concern has complicated the conversation around omega-3 supplementation. Several large trials, including the REDUCE-IT and STRENGTH trials, have suggested that omega-3 supplementation might be linked to an increased risk of atrial fibrillation (AF), a common cardiac arrhythmia characterized by an irregular and often rapid heart rate. These findings have sparked debate over whether omega-3s could contribute to this potentially serious heart condition, leaving clinicians and health-conscious individuals uncertain about the safety of these supplements. However, not all the research supports this elevated risk. This discrepancy raises important questions about how we interpret the data from various studies, the design of those trials, and whether other factors might be influencing these results. Understanding this issue in depth is crucial for making informed decisions about omega-3 supplementation and its potential risks and benefits. In this episode we walk through the studies and the key points to consider. Timestamps: 00:30 Updates on Alan’s upcoming study 05:06 Atrial Fibrillation and Omega-3 14:52 RCTs and AFib: Key Studies 29:14 Meta-Analyses and Dose-Response 46:46 Practical Implications and Recommendations 53:53 Key Ideas Segment (Premium-only) Links:
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#537: Appetite Regulation, Metabolic Compensation and More – Stephan Guyenet, PhD
10/01/2024
#537: Appetite Regulation, Metabolic Compensation and More – Stephan Guyenet, PhD
This is an “ask me anything” (AMA) episode with Dr. Stephan Guyenet, an expert in obesity neuroscience and eating behavior. This episode was originally published on . If you’re interested in subscribing to Sigma Nutrition Premium, then check all the details . Questions Answered: [04.27] If we surgically remove adipose tissue, do leptin levels suddenly drop? How would this impact hunger over time? [06.56] How does chronic energy restriction (or following a crash diet) affect long-term appetite regulation? [13.21] How do anorexia and pronounced obesity defy the rules of metabolic compensation? [24.12] Why do some SDRIs (serotonin–dopamine reuptake inhibitors) reduce hunger/appetite? [28.02] Can an algorithm really decipher someone’s “ideal weight? [33.08] Could the “brain microbiome” impact appetite regulation and/or obesity? [35.34] In our current environment, are the only efficacious interventions drugs and bariatric surgery? [46.01] What should we make of claims by Gary Taubes about insulinogenic foods? [52.37] Is there a maximum duration someone should spend in fat loss (or weight gain) phases? [53.43] Why do some people struggle to gain weight? Links:
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Caffeine Metabolism and Individual Variability
09/24/2024
Caffeine Metabolism and Individual Variability
Questions Answered in This Episode [02:28] Caffeine metabolism and individual variation. [14:47] High-sodium electrolyte supplements & recreational trainees. [32:55] Is a “too low” BMI a problem? [41:38] Are claims about vegan diets being nutritionally insufficient overblown? [51:33] Familial hypercholesterolemia & further lipid-lowering [58:05] Menopause, resistenace training and progressive overload [01:11:56] Does body weight matter if someone has healthy behaviours? This episode is one of our Premium-exclusive AMA (ask me anything) episodes, where we answer questions submitted by Premium subscribers. To listen to the full episode, you’ll need to be a and access the episode on the private Premium feed. Otherwise, you can hear the first question on the public feed of the podcast. Links:
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#536: Improving Sleep in Combat Sports Athletes – Ian Dunican, PhD
09/17/2024
#536: Improving Sleep in Combat Sports Athletes – Ian Dunican, PhD
In the world of combat sports, optimizing performance extends beyond physical training and nutrition—sleep plays a critical role. Maladaptive sleep behaviors, such as inconsistent sleep schedules and inadequate sleep duration, can significantly impair an athlete’s performance by reducing cognitive function, reaction time, and recovery ability. Understanding these impacts is crucial for athletes and coaches seeking to enhance performance through more effective sleep strategies. One of the key challenges combat sports athletes face is managing the effects of shift work and irregular event timings, which often conflict with typical training schedules. What are some strategies to mitigate these challenges, such as adjusting sleep schedules in advance? And what are the implications of jet lag for athletes traveling to major competitions? While technology offers valuable tools for tracking sleep, there are potential drawbacks, including reliance on inaccurate data or the psychological effects of constant monitoring. By educating athletes and coaches on best practices for sleep, they can make informed adjustments to training regimens, ultimately enhancing overall performance. In this episode, sleep scientist Dr. Ian Dunican discusses his work related to understanding and improving sleep behaviors in combat sports athletes. Timestamps: 01:43 Introduction to the Episode 04:38 Discussion on Recent Research Paper 09:52 Sleep Behaviors in Athletes 13:11 Questionnaire and Study Findings 20:38 Common Sleep Disorders in Athletes 33:23 Impact of Training Schedules on Sleep 34:25 Practical Tips for Better Sleep 41:17 Phases of Training and Their Importance 42:31 Understanding Chronotypes and Sleep Habits 45:19 Wearable Devices and Sleep Tracking 53:05 Practical Advice for Coaches and Athletes 59:03 Travel, Jet Lag, and Sleep for Athletes Links: Enroll in the next cohort of our course (with links to studies in this episode) (20% off with code MELIUS20)
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#535: Is This Meta-analysis Good or Bad? – How to Critique Nutrition Studies
09/10/2024
#535: Is This Meta-analysis Good or Bad? – How to Critique Nutrition Studies
To many, meta-analyses are seen as a research tool that is often regarded as the pinnacle of evidence in nutrition science. But is this accurate? What exactly makes a meta-analysis reliable or flawed? How can we distinguish between a well-conducted study and one that might mislead even the most well-intentioned reader? In this episode, through three concrete examples, we explore the fundamental principles of meta-analyses, focusing on key aspects such as study selection, heterogeneity, and effect sizes. We discuss how these elements can significantly impact the conclusions drawn from a meta-analysis and what you should look out for when interpreting their results. Whether you’re a nutrition professional, a researcher, or simply someone interested in the science behind dietary guidelines, this discussion will help you navigate the often murky waters of meta-analytic research. Timestamps: 05:14 Understanding Meta-Analyses 12:11 Example 1: Dairy Consumption and Health 39:06 Example 2: Meta-Analysis on Carbohydrate Intake 54:59 Example 3: Meta-Analysis on Intermittent Fasting 01:02:44 Challenges in Meta-Analysis of Intermittent Fasting 01:13:56 Key Ideas Segment (Premium-only) Links: Enroll in the next cohort of our course Meta-analyses discussed in the episode: Subscribe to
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#534: Are Plant-Based Meat Alternatives Healthy? – Matthew Nagra, ND
09/03/2024
#534: Are Plant-Based Meat Alternatives Healthy? – Matthew Nagra, ND
The debate between animal-based and plant-based meat alternatives (PBMAs) has garnered significant attention, especially concerning their impact on cardiovascular health. As PBMAs become increasingly popular, questions about their nutritional profiles and long-term health implications have emerged. Are these alternatives genuinely healthier than traditional meat, or do their highly processed nature and high sodium content undermine potential benefits? This discussion is crucial as dietary choices increasingly influence public health policies and consumer behaviors. Dr. Matthew Nagra’s recent review in the Canadian Journal of Cardiology sheds light on these issues by analyzing the nutritional differences between PBMAs and meat. The review highlights the potential cardiovascular benefits of PBMAs, such as lower levels of saturated fat and cholesterol, alongside higher fiber content. However, the review also points out the significant variability in PBMAs’ nutritional content, raising questions about standardization and consumer guidance. Understanding these differences is key to making informed dietary decisions and shaping future food industry practices. With growing consumer interest and public health implications, several pertinent questions arise: How do different PBMAs compare in their nutritional impact? What role does food processing play in their health outcomes? How can consumers make the best choices given the variability in PBMAs? In our discussion, Dr. Nagra will cover all these details, providing a comprehensive look at the current state of PBMAs and their role in a healthy diet. Timestamps: 01:59 Introducing Dr. Matthew Nagra 10:48 Nutritional Profiles of Plant-Based Meat Alternatives 14:39 Cardiovascular Risk Factors and Review Findings 21:17 Public Perception and Criticisms 25:10 Practical Advice for Choosing Plant-Based Meat Alternatives 34:29 Future Research Directions 43:51 Key Ideas Segment (Premium-only) Links: Subscribe to Sigma Nutrition Premium Go to episode page Receive our free weekly email: Enroll in the next cohort of our course
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Timing of Eating: Energetic Hypothesis (SNP32)
08/27/2024
Timing of Eating: Energetic Hypothesis (SNP32)
In the ongoing exploration of weight loss strategies, the timing of food intake has emerged as a fascinating area of study. While traditional advice often focuses on what we eat, growing evidence suggests that when we eat could also play a crucial role in weight management. This concept, known as chrononutrition, examines how our body’s internal clock influences the metabolic processes associated with food intake. Could adjusting meal times offer a new pathway to effective weight loss? Recent research has delved into various hypotheses, including the energetic hypothesis, which proposes that meal timing can impact energy expenditure and intake. Studies have shown that consuming more calories earlier in the day could potentially enhance weight loss, independent of total daily calorie intake. This intriguing possibility has led scientists to investigate the mechanisms behind these effects, such as the thermic effect of feeding and diurnal variations in metabolism. Understanding these mechanisms could transform our approach to dietary planning and obesity management. Dr. Alan Flanagan will be covering all the details in this episode, where he explores the latest evidence on meal timing and its impact on weight loss. He will dissect key studies, challenge prevailing assumptions, and provide a comprehensive analysis of the energetic hypothesis. Join us as we navigate the complexities of chrononutrition and uncover whether altering the timing of our meals can truly make a difference in our weight loss journeys. This episode is a Premium-exclusive episode. Subscribe to to listen to the full episode. Links: Subscribe to Enroll in the next cohort of our course Go to
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#533: Making Sense of Omega-3 Supplement Trials – Prof. JoAnn Manson, MD, DrPH
08/20/2024
#533: Making Sense of Omega-3 Supplement Trials – Prof. JoAnn Manson, MD, DrPH
The impact of omega-3 fatty acids on chronic disease risk has been a topic of considerable interest and research. The VITAL trial, which assessed the effects of vitamin D and omega-3 supplements on various health outcomes, including cardiovascular disease and cancer, provided insightful findings. Additionally, numerous other supplement trials have examined different dosages and formulations of omega-3s, yielding mixed results. Some trials have highlighted significant benefits, while others have shown minimal impact, leading to ongoing debates in the scientific community. Reconciling this evidence base requires a nuanced understanding of the study populations, dosages, and specific health outcomes investigated. The variability in results can often be attributed to differences in trial design, such as whether the focus was on primary or secondary prevention, the baseline dietary intake of participants, and the specific types of omega-3 supplements used. Understanding these nuances is crucial for making informed recommendations about omega-3 supplementation for chronic disease prevention. In this episode, Professor JoAnn Manson will delve into the complexities of omega-3 research, discussing the VITAL trial in detail, comparing it with other significant studies, and providing insights into how to interpret and reconcile the diverse findings in the context of chronic disease risk. Timestamps: 03:21 The VITAL Trial Explained 05:39 Biological Mechanisms and Observational Studies 07:25 Primary vs. Secondary Prevention 10:47 Key Findings from the VITAL Trial 13:39 Subgroup Analyses and Future Research 19:58 Dosage Considerations and Risks 23:47 Impact of Omega-3 on Chronic Diseases 32:18 Nuances in Omega-3 Research 44:27 Future Research Directions 48:54 Key Ideas Segment (Premium-only) Links: Receive our free weekly email: Enroll in the next cohort of our course
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#532: Dietary Fat: Evidence vs. Misinformation – Alice Lichtenstein, DSc
08/13/2024
#532: Dietary Fat: Evidence vs. Misinformation – Alice Lichtenstein, DSc
In the realm of nutrition science, few topics have sparked as much debate and evolution in understanding as the impact of dietary fat on cardiovascular health. Dr. Alice Lichtenstein, a renowned expert in nutrition and cardiovascular disease, brings clarity to this complex field. Her extensive research at several prestigious institutions has been pivotal in shaping contemporary dietary guidelines. Dr. Lichtenstein delves into the journey from early observational studies that linked high-cholesterol diets to cardiovascular risk to more nuanced insights emphasizing the types of fats consumed. The discussion highlights the critical shift from merely reducing total fat intake to replacing saturated fats with unsaturated fats, reflecting the latest evidence-based recommendations. Furthermore, the conversation addresses the variability in individual responses to dietary changes and the ongoing debate over the most accurate biomarkers for assessing cardiovascular risk. Dr. Lichtenstein also tackles the pervasive issue of nutrition misinformation and underscores the necessity of robust, evidence-based public health guidelines. This episode offers a comprehensive exploration of whole dietary patterns, the importance of examining food choices in context, and the role of public health policy in fostering healthier eating environments. Join us to gain a deeper understanding of how dietary fat influences health and the critical considerations for future nutrition research and recommendations. Timestamps: 03:15 Dr. Lichtenstein’s Academic Background 05:47 Evolution of Dietary Fat Research 14:47 Understanding Cholesterol and Lipoproteins 23:47 Dietary Patterns and Public Health 29:51 Seed Oils & Nutrition Misinformation 34:06 Future Directions in Nutrition Research 47:11 Key Ideas Segment (Premium-only) Links: Subscribe to Receive our free weekly email: Enroll in the next cohort of our course
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#531: Correlation, Causation & Cliché
08/06/2024
#531: Correlation, Causation & Cliché
In the realm of nutrition science and health, understanding the intricate relationship between various factors and health outcomes is crucial yet challenging. How do we determine whether a specific nutrient genuinely impacts our health, or if the observed effects are merely coincidental? This intriguing question brings us to the core concepts of correlation and causation. You’ve likely heard the adage “correlation is not causation,” but what does this truly mean in the context of scientific research and public health recommendations? Can a strong association between two variables ever imply a causal relationship, or is it always just a statistical coincidence? These questions are not merely academic; they are pivotal in shaping the guidelines that influence our daily lives. For instance, when studies reveal a link between high sodium intake and hypertension, how do scientists distinguish between a mere correlation and a true causal relationship? Similarly, the debate around LDL cholesterol and cardiovascular disease hinges on understanding whether high cholesterol levels directly cause heart disease, or if other confounding factors are at play. Unraveling these complexities requires a deep dive into the standards of proof and the different models used to assess causality in scientific research. As we delve into these topics, we’ll explore how public health recommendations are formed despite the inherent challenges in proving causality. What methods do scientists use to ensure that their findings are robust and reliable? How do they account for the myriad of confounding variables that can skew results? By understanding the nuances of these processes, we can better appreciate the rigorous scientific effort that underpins dietary guidelines and health advisories. Join us on this exploration of correlation, causation, and the standards of proof in nutrition science. Through real-world examples and critical discussions, we will illuminate the pathways from observational studies to actionable health recommendations. Are you ready to uncover the mechanisms that bridge the gap between scientific evidence and practical health advice? Let’s dive in and discover the fascinating dynamics at play. Timestamps: 01:32 Understanding Correlation and Causation 03:54 Historical Perspectives on Causality 06:33 Causal Models in Health Sciences 14:53 Probabilistic vs. Deterministic Causation 30:52 Standards of Proof in Public Health 36:44 Applying Causal Models in Nutrition Science 58:54 Key Ideas Segment (Premium-only) Links: Enroll in the next cohort of our course Subscribe to Receive our free weekly email: Related episode:
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What is Regression to the Mean? (SNP31)
07/30/2024
What is Regression to the Mean? (SNP31)
Regression to the Mean (RTM) is a statistical phenomenon where extreme values on one measurement tend to move closer to the average on subsequent measurements due to natural variability. In this , Danny gives an explanation of this concept with some examples in nutrition research.
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#530: Evidence-based Strategies for Learning & Skill Acquisition – Scott Young
07/23/2024
#530: Evidence-based Strategies for Learning & Skill Acquisition – Scott Young
The concept of “learning how to learn” focuses on meta-learning, which involves improving one’s own learning strategies. Instead of just absorbing information, meta-learners refine the skills that make learning itself more effective. Cognitive science supports various learning strategies by exploring how the brain processes information. Techniques such as spaced repetition, active recall, and interleaving can improve long-term retention and understanding. Improving abilities in specialized areas, like reading and interpreting research, involves strategic approaches. Similarly, becoming more knowledgeable about nutrition requires staying updated with the latest research and critically evaluating findings to boost proficiency and confidence in the field. In this podcast episode, Scott Young discusses these themes, offering insights from his work on learning optimization. He shares practical methods for improving learning efficiency, particularly in reading research and expanding knowledge in nutrition. Scott’s expertise provides a valuable framework for enhancing cognitive abilities and achieving more effective learning outcomes. Links: Receive our free weekly email: Related Episode: Timestamps 02:13 Introduction to Topic 04:41 Conversation with Scott Young Begins 06:56 Insights on Learning and Cognitive Science 12:42 Effective Learning Strategies 20:27 Overcoming Mental Barriers 31:14 Effective Teaching Strategies 35:14 The Importance of Feedback in Learning 38:52 Optimizing Your Learning Environment 44:29 Translating Complex Information for a General Audience 52:32 Key Ideas (Premium-Only)
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#529: Addressing Popular Claims About Cholesterol, Dietary Fat and Heart Disease
07/16/2024
#529: Addressing Popular Claims About Cholesterol, Dietary Fat and Heart Disease
In episode 529 of Sigma Nutrition Radio, we discuss all things related to cholesterol, atherosclerosis, heart disease, and dietary fat. The discussion extensively covers the impact of LDL cholesterol and ApoB on atherosclerotic plaque progression, cardiovascular events, and the benefits of early LDL lowering interventions, particularly through the use of PCSK9 inhibitors alongside statins. We address misconceptions prevalent in the low-carb and carnivore communities, dissect claims regarding saturated fats, and elucidate why atherosclerosis predominantly affects arteries and not veins. The episode sheds light on the nuanced mechanisms of cholesterol metabolism, the significance of different lipid particles, and the limited dietary impact on LP(a) levels. Comprehensive evidence-based insights and practical recommendations for dietary patterns and cardiovascular health interventions are provided, offering clarity on these complex topics. Note: This discussion is hosted by Simon Hill, and originally appeared as an episode of The Proof podcast. Links: Receive our free weekly email: Timestamps: 07:19 Understanding Cholesterol and Lipoproteins 14:35 The Role of ApoB in Cardiovascular Risk 25:10 Atherogenic Lipoproteins and Their Impact 37:42 Causal Pathways and Biomarkers in Heart Disease 47:02 Understanding Residual Risk and Triglycerides 49:46 Paul Saladino’s Claims on LDL and Metabolic Health 01:03:01 Addressing Concerns About Lowering Cholesterol 01:16:16 The Importance of Early Intervention in Cholesterol Management 01:23:36 The Future of Cholesterol Management and Gene Editing 01:28:24 Atherosclerosis in Arteries vs. Veins 01:36:08 Dietary Interventions to Lower ApoB Levels 01:47:55 Modifying Keto Diet for Better Health Outcomes 01:56:33 Plant-Based Diets and Fat Consumption 02:05:10 Understanding Lp(a) and Its Impact on Health
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#528: Is Unprocessed Red Meat Problematic for Our Health?
07/09/2024
#528: Is Unprocessed Red Meat Problematic for Our Health?
The consumption of red meat, specifically the distinction between unprocessed and processed varieties, has been a subject of considerable debate in nutritional science and public health. There is a fair amount of confusion and lack of clarity surrounding this issue. While the harmful effects of processed meat are well-documented and less controversial, the evidence concerning unprocessed red meat is less consistent. This inconsistency often leads to a gray area in scientific discussions and public perception. In examining unprocessed red meat, we encounter a spectrum of claims, including minimal evidence of harm, context of overall diet and mechanistic concerns. Epidemiological evidence shows varied health outcomes related to red meat consumption across different populations. These variations underline the importance of defining and measuring “high” and “low” intake levels accurately in research. The challenges in nutrition research, including methodological flaws in meta-analyses and the rapid dissemination of simplified study results, can impact public health recommendations. Misinterpretations can arise from comparisons within narrow intake ranges or from studies failing to specify absolute intake levels. This podcast episode’s goal is to clarify existing evidence, acknowledge areas needing further research, and explore why this topic is significant in the broader context of nutrition science, aiming to equip healthcare professionals with the knowledge needed to make nuanced and effective dietary recommendations. Links: Receive our free weekly email: Want to advance your understanding of nutrition science? . Go to Subscribe to Timestamps 01:00 Introduction to the issue 03:16 Processed vs. unprocessed red meat 05:54 Health guidelines and recommendations 06:56 Epidemiological evidence and dose thresholds 09:55 Biological mechanisms and plausibility 21:00 Criticisms and misinterpretations in research 40:42 Substitution analyses and dietary patterns 46:37 Mendelian randomization and genetic studies 56:31 Effect modifiers and confounders 01:13:18 Key Ideas Segment (Premium-only)
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#527: How to Prevent & Treat Hypertension – Dr. Mohammed Alo, DO
06/25/2024
#527: How to Prevent & Treat Hypertension – Dr. Mohammed Alo, DO
Hypertension, commonly known as high blood pressure, is a silent yet prevalent health issue that affects millions of people worldwide. Often going unnoticed until significant damage has been done, hypertension can lead to severe cardiovascular complications if not properly managed. Mechanistically, the causes of hypertension are complex, involving both genetic and lifestyle factors. The management of hypertension presents multifaceted challenges, encompassing both pharmaceutical treatments and lifestyle modifications. From a prevention and management standpoint, understanding the interplay between genetics and lifestyle is crucial. This raises several important questions… To what extent do genetic factors contribute to hypertension risk compared to lifestyle choices, and how does this interaction influence disease progression? What role does lifestyle play in managing hypertension, and is there evidence supporting the influence of specific dietary patterns and nutrients, particularly sodium and potassium, on blood pressure control? How do exercise and physical activity impact blood pressure, and what types of exercise are most beneficial for individuals with or at risk of hypertension? What are the main categories of antihypertensive medications, and how do these drugs work to lower blood pressure? What are the potential side effects, and how should clinicians decide on the best treatment approach for individual patients? In this episode, we are joined by Dr. Mohammed Alo, a board-certified cardiologist and internal medicine specialist, who will help us understand the intricacies of hypertension and how it can be effectively controlled. Links: Receive our free weekly email: Subscribe to Timestamps: 03:28 Dr. Alo’s Background and Expertise 08:40 Understanding Blood Pressure and Its Implications 10:26 Causes and Diagnosis of High Blood Pressure 12:42 Lifestyle Modifications and Treatment Options 30:26 Medications for Blood Pressure Management 38:34 Combination Therapy and Patient Variability 43:11 Debunking Myths About Sodium and Blood Pressure 57:29 Exercise and Lifestyle Interventions
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#526: Eating Rate, Food Texture & Satiation – Marlou Lasschuijt, PhD
06/18/2024
#526: Eating Rate, Food Texture & Satiation – Marlou Lasschuijt, PhD
Food science and behavior are intimately connected. One critical but often overlooked facet of this connection is food texture and its substantial impact on eating behavior and energy intake. Food texture encompasses characteristics such as hardness and structure. It categorizes food into liquids, semi-solids, and solids, each with a wide range of textures—from dry and crispy to elastic and more substantial. This classification deeply affects how we consume food. The time it takes to chew and swallow a food item can vary greatly based on its texture. Different textures can also influence the speed at which satiety signals are triggered. Eating rate is a highly individual trait, stable over time, and consistent across different contexts. Some people are naturally slower eaters, while others consume food quickly. This variance can have significant implications for energy intake and body weight. In this episode, Dr. Marlou Lasschuijt, an assistant professor in the Sensory Science and Eating Behaviour group at Wageningen University, discusses the above topics and their implications. Links: (for study notes and transcripts) Receive our free weekly email: Timestamps: 00:14 Introduction 00:47 Dr. Lasschuijt’s Research Focus 04:23 Understanding Food Texture and Eating Behavior 06:37 Impact of Food Texture on Satiation and Eating Rate 16:55 Applications and Innovations in Food Science 18:31 Unanswered Questions 25:34 Practical Recommendations 27:00 Current and Upcoming Research Projects
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#525: Cholesterol-Lowering Medication – Dr. Paddy Barrett
06/11/2024
#525: Cholesterol-Lowering Medication – Dr. Paddy Barrett
Cholesterol-lowering medications, particularly statins, play a pivotal role in reducing low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apoB) concentrations, which are causal markers in atherosclerosis development. The efficacy of these medications is well-documented, with numerous clinical trials demonstrating substantial benefits in reducing cardiovascular events and improving overall mortality rates. Despite the robust evidence supporting the benefits of cholesterol-lowering medications, there are various misconceptions and misunderstandings regarding their use. One common myth is that these drugs are unnecessary for those without overt cardiovascular symptoms, ignoring the preventative benefits for at-risk individuals. Concerns about side effects, such as muscle pain, liver damage, and cognitive impairment, are often exaggerated. While side effects are possible, they are typically mild and manageable. Regular monitoring and adjustments by healthcare providers can help mitigate any adverse effects, ensuring that the benefits of reducing LDL-C and apoB far outweigh the risks. In this episode, preventative cardiologist Dr. Paddy Barrett discusses the different types of lipid-lowering medications, their mechanisms of action, the side effects that may occur, and the misconceptions about the drugs that are unfortunately widespread. Timestamps: 00:14 Introduction 03:26 Dr. Barrett’s Background 04:50 What is “Lipid Lowering”? 05:30 Overview of Lipids and Atherosclerosis 09:58 Setting Targets for Lipid Levels 15:52 Medications for Lowering LDL and ApoB 20:12 Statins: Types, Effects, and Side Effects 35:38 Addressing Concerns and Misconceptions 42:47 Future of Lipid Lowering Therapies Links: Book: Receive our free weekly email:
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#524: Strength & Fitness Levels for Reducing Chronic Disease Risk & Promoting Health Ageing – Jordan Feigenbaum, MD
06/04/2024
#524: Strength & Fitness Levels for Reducing Chronic Disease Risk & Promoting Health Ageing – Jordan Feigenbaum, MD
When aiming for healthy aging and reducing chronic disease risk over the lifecourse, exercise, specifically a combination of resistance training and cardiorespiratory fitness, has a fundamental role to play. In addition it can mitigate age-related declines and support independence in later years. A strong evidence base exists showing the benefits of increased strength and cardiorespiratory fitness on a range of important outcomes related to lifespan and healthspan. But some intriguing questions remain, such as: How strong is strong enough? At what point do we maximize the benefits of exercise? How “fit” do we need to be? Is simple participation enough or do we need a true training adaptation? How can this actually be implemented in practice so that it is doable? In this episode, Dr. Jordan Feigenbaum shares his insights on this topic and offers advice on how we can increase our probability of a long healthspan, through exercise interventions. Links: Timestamps: 04:40 Dr. Feigenbaum’s Journey and Barbell Medicine’s Mission 05:57 Defining and Achieving Healthy Aging 10:37 The Impact of Exercise on Health and Longevity 28:52 Strength Training: How Much is Enough? 38:43 Muscle Mass vs. Strength: What Matters More for Health? 47:18 The Paradox of Muscle Mass vs. Strength 49:05 Designing an Effective Strength Training Program 01:01:27 Cardiorespiratory Fitness: Importance and Assessment 01:06:19 Optimizing Cardio Training: Intensity and Volume
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SNP29: Athletes & Plant-Based Diets – Evidence & Application in Practice
05/28/2024
SNP29: Athletes & Plant-Based Diets – Evidence & Application in Practice
Contemporary society is witnessing a growing interest in, and embracing of, plant-based diets. Numerous athletes are now gravitating towards such dietary choices, motivated by concerns for health, performance or ethics. Consequently, coaches, nutritionists, and other fitness experts find themselves increasingly tasked with guiding athletes who adhere to plant-based diets. For coaches and trainers, understanding the possible impacts of these dietary preferences on athletes’ objectives is paramount, as is devising dietary plans that optimize their performance. This episode discusses the scientific and practical aspects of supporting athletes who have adopted a vegetarian lifestyle and diet. Links:
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#523: How Trustworthy is the Food Frequency Questionnaire in Evaluating Dietary Intake? – Deirdre Tobias, ScD
05/21/2024
#523: How Trustworthy is the Food Frequency Questionnaire in Evaluating Dietary Intake? – Deirdre Tobias, ScD
The Food Frequency Questionnaire (FFQ) stands as a cornerstone in nutritional research, offering valuable insights into dietary patterns and habits over a specified period. Despite its widespread use and established utility, the FFQ has not been immune to criticism, much of which arises from a misunderstanding of its purpose and inherent limitations. At its core, the FFQ is designed to assess the frequency and quantity of food consumption, aiming to capture long-term dietary behaviors rather than precise intake levels. Researchers employ it to investigate relationships between diet and various health outcomes, such as chronic diseases or nutritional deficiencies. However, critics argue that its reliance on self-reported data introduces biases and inaccuracies, leading to potential misestimation of nutrient intake. Additionally, some detractors question the FFQ’s ability to capture sporadic or infrequent dietary choices accurately. Yet, it’s crucial to recognize that the FFQ serves a specific purpose within the realm of nutrition research. While there are no doubt limitations, its strength lies in its ability to capture habitual dietary behaviors over an extended period. Moreover, researchers employ various strategies, such as validation studies and data adjustment techniques, to enhance the FFQ’s reliability and validity. In this episode, world-leading nutrition epidemiologist Dr. Deirdre Tobias discusses the development of the FFQ, the key concepts that are crucial to understand, common criticisms of the FFQ, and how we should evaluate the utility of this tool. Links: Interested in improving your ability to read nutrition research?
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#522: Does Personalized Nutrition Outperform General Dietary Advice?
05/14/2024
#522: Does Personalized Nutrition Outperform General Dietary Advice?
Links: About This Episode: “Personalized nutrition” has been promoted as an approach that will improve people’s health by prescribing them specific dietary recommendations based on their own genetic and phenotypic data. The premise is that given we each respond differently to foods, having general dietary recommendations may be doing many people a disservice. And by using an array of personal data, it is now possible to give unique diets that improve health. The early and interesting findings of research in this area was met with much fanfare, and indeed, many companies are now offering commercial direct-to-consumer services based on genetic and physiological testing, followed by “personalized” dietary prescription. Such testing may include genetic tests, microbiome testing, glucose monitoring data, and more. This data is then fed into machine learning algorithms to prescribe dietary recommendations. However, do the marketing claims match the current evidence? Does the “proof” it works that is often cited, actually back up the claims? Do personalized nutrition diets actually lead to improved health outcomes over generic, conventional dietary recommendations? Do personalized nutrition diets lead to better outcomes than standard dietetic/nutrition practice? To answer these questions, we go through the main studies cited in favor of personalized nutrition being superior to typical dietary advice, and see if they indeed support the claims. So is personalized nutrition superior to standard dietary advice? Let’s find out… Note: This was originally a Premium-exclusive episode. If you’d like to get more episodes like this, subscribe to .
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#521: How Does Coffee Impact Our Health?
05/07/2024
#521: How Does Coffee Impact Our Health?
The relationship between coffee and health is complex, encompassing areas like blood lipids, cardiovascular disease, neurodegenerative diseases, anxiety, and depression. Coffee has an interesting nutrient profile and contains diverse bioactive compounds that influence metabolism. Coffee has a potential impact on cardiovascular disease risk, with mechanisms that highlight potential benefits and some concerns. There may be an impact on blood pressure and blood lipid, but there are important nuances to this. Some research suggests that moderate intake may protect against neurodegenerative diseases like Alzheimer’s and Parkinson’s, with some mechanisms proposed for the observation. Coffee’s effects on anxiety, depression, and sleep are common talking points and worthy of addressing. The context of the consumption and the individual in question will dictate the likely effects. Ultimately, coffee’s effects on health are influenced by various factors, warranting personalized approaches to consumption. In this episode, Simon Hill puts some questions to Danny Lennon about the impact of coffee on our health. Links:
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