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 Sigma Nutrition Premium to listen to the full episode.

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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)

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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

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The term 'tactical populations' has been applied to those working in law enforcement, fire, first responders, and military. In addition to the importance of their work, the work they do itself presents some challenges for health and nutrition.

Despite the fact that such individuals make up a significant number of the population and their work plays a crucial role in society, there is currently very little research on fire and law enforcement nutrition. Most research is on the prevalence of disease and the occupational risk factors and related pathophysiology. Lifestyle research, descriptive and interventions, is way behind.

Dr. Jill Joyce is the co-director of the OSU Tactical Fitness and Nutrition Lab at Oklahoma State University. She does research looking at real-world interventions in these populations, particularly firefighters, in an attempt to improve their diets and health.

In this episode, we look at both the theoretical and pragmatic realities of improving diet and health in firefighters and some other tactical populations.

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When it comes to eating to promote muscle hypertrophy, muscle repair/recovery and maintenance of mass and function, protein has been an obvious focus. Indeed muscle mass and quality are dependent on the continuous remodeling of skeletal muscle proteins. This is related to the amount of muscle protein balance, i.e. the net difference between muscle protein synthesis (MPS) and muscle protein breakdown (MPB). Because of this, MPS has long been used as a proxy measure for muscle repair and/or growth of muscle.

Protein feeding increases MPS, with the amino acid leucine having a specifically strong impact on MPS. Therefore both the dose of protein and the amino acid profile of the protein have been looked at to assess which protein sources are "superior" for muscle mass and function. This has typically led to viewing animal proteins as better than plant proteins.

But many assumptions are layered into conversations on the topic. In this episode we explore some important points that are often neglected. Is MPS as reliable as we assume? Does the amino acid profile tell us everything about the anabolic effect of a protein? Does dose and timing matter as much as we think? How does the picture change when we look at whole foods or mixed meals?

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The brain plays a central role in both physical and psychological function and performance. The brain also has a very high energy demand. In addition, fatiguing conditions can cause impairment of cognitive performance.

One area of research in neurometabolism related to the potential use of nutrients on improving cognitive function, as well as "rescuing" the fatigue-related declines in performance.

Nick Gant is Director of the Exercise Neurometabolism Laboratory at the University of Auckland. His group uses interdisciplinary approaches from the nutritional sciences and neurosciences to investigate the role of nutrition in brain health and performance. Nick is particularly interested in foods and supplements that prevent brain fatigue and improve physical and cognitive function.

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This episode was oringally published as one of our "Expert – ask me anything" (AMA) episodes, which we published for Premium prescribers. In such bonus episodes, we collect questions from Premium subscribers and ask them direct to a world-class expert and past podcast guest.

If you're interested in subscribing to Sigma Nutrition Premium, then check all the details here.

In this episode Prof. Stu Phillips takes questions about synethized whey protein, plant proteins, post-exercise MPS, and many other topics related to protein, muscle function and ageing.

It has been consistently shown in research that elevated dietary sodium consumption is associated with high blood pressure and an increased risk of cardiovascular disease. In addition, low levels of dietary potassium intake are associated with these same risks. However, there is some debate on how to characterize these relationships.

In a study published in European Heart Journal in July 2022, using data from the EPIC-Norfolk study, researchers attempted to answer whether the associations between potassium and both blood pressure and cardiovascular disease: 1) differ between men and women? and 2) depend on daily sodium intake.

In this episode Dr. Alan Flanagan and Danny Lennon discuss the details of this study and then link it to the overall evidence base and what this may mean for potassium (and sodium) intake considerations.

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A study published in March 2022 suggested that consumption of artificial (non-nutritive) sweeteners is associated with a 13% increase in risk of cancer.

And so in this episode, Dr. Alan Flanagan, Dr. Niamh Aspell, and Danny Lennon discuss this specific study and give their thoughts on what are fair conclusions to come to.

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While we've never known more about diet and health, there remain many unanswered questions in nutrition science. However, there is often disagreements on how best to answer these questions, particularly in relation to informing practical diet advise that meaningfully improves health.

Prof. Norman Temple is one academic who has written on a number of these issues. One issue he highlights is the large discrepency in the practical value we have attained from cohort studies and RCTs, relative to mechanistic research. Another is the limitations of RCTs for nutrition-specific research questions.

In this episode, Prof. Temple discusses these issues, as well as what strategies can actually improve population diet, and thus health.

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A recent study reported a higher risk of developing melanoma in people who ate a relatively high intake of fish. This study caused headlines and it was picked up by many outlets (including the New York Times, Sky News, etc.).

In this episode, Alan and Danny dig into the nuances of this study to see if the headlines are justified.

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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.

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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

This is an "ask me anything" (AMA) episode, which means a world-class expert and past podcast guest comes on the podcast to answer questions submitted by you, our podcast listeners.

Stephan Guyenet spent 12 years in academia studying neurodegenerative disease and obesity neuroscience. He was a postdoctoral fellow at the Univeristy of Washington, studying the neuroscience of obesity and eating behavior. Previous to that he completed a PhD in neuroscience.

Stephan is the author of the popular and well-received book 'The Hungry Brain', which lays out the science behind the brain's role in obesity.

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1. "When someone undergoes liposuction or other surgery that removes adipose tissue, is there a sudden reduction in leptin levels? While this may reduce leptin resistance, could the drop in leptin lead to increased hunger over time?"
2. "What is the current research around how chronic energy restriction (or following crash diets) affects appetite hormones and/ or appetite regulation long term? Is there a physiological mechanism influencing overeating attributable to appetite dysregulation caused by chronic dieting? I ask as this is something I am often tackling in my nutrition consultancy but research in biochemical and physiological mechanisms seems lacking."
3. "Can you talk about the conditions of anorexia and morbid obesity and how they essentially defy the rules of metabolic compensation? In other words- I understand anorexia to be a mental health condition where the individual starves themselves with a purpose to control weight. And morbid obesity being excessive consumption despite over fatness, etc. If the body has these numerous mechanisms by which calorie restriction or calorie over- consumption results in these compensatory processes-driving us to eat more/less slow us down/speed us up, and many more; do these individuals not "hear" these signals or are they just adept at ignoring them or is it that their bodies have lost the ability to compensate for their under or over consumption? Additionally, can anyone become anorexic or morbidly obese? Or is it merely genetics?"
4. "Why do some SDRIs (serotonin–dopamine reuptake inhibitors) and serotonin precursors reduce hunger/appetite? E.g. 5-HTP and Wellbutrin (Bupropion)"
5. "Question about the ideal weight program: As an iOS developer, my instinct is to assume determinism and quantifiability of the entire universe. I believe this to be fundamentally true. But what is hypothetically possible differs from what we can realistically know. I worry that attempts like yours to quantify some seemingly qualitative measures are doomed. I have similar concerns about happiness research. How do you reassure yourself you can really construct an algorithm that deciphers the "ideal weight program" for any given user – do you rely on averages?"
   a. Quick explanation of the ideal weight program
6. "In 2018 a poster was presented at the annual meeting of the Society for Neuroscience titled 'The human brain microbiome; there are bacteria in our brains!' which showed bacteria apparently penetrating and inhabiting the cells of healthy human brains. While the work was preliminary, have you heard of any further work in this area? What is your opinion on the possibility that, if bacteria do inhabit the brain, they could play a part in appetite regulation and/or obesity similar to how the gut microbiome can affect our health?"
7. "It seems like there are significant differences in policies put forth between researchers from biomedical backgrounds and ones from public health policy backgrounds. Dr [David] Allison touched on this during recent interviews, noting that there is very little evidence regarding the efficacy of upstream obesity prevention interventions, such community gardens, combatting food deserts, nutrition education, and cooking classes. On the other hand, governments are increasingly turning to such interventions, as well as policies such as front of pack labelling (Canada, 2022), nutrition facts tables, calorie labelling on menus, as well as the aforementioned ones. Given your research on determinants of health and obesity, what are some of the most promising interventions to prevent NCD morbidity, as well as stones unturned in public health policy? Would you agree with individuals such as Dr Allison that in our current environment, the only efficacious interventions are drugs and bariatric surgery?"
8. Question based on your debate on JRE with Gary Taubes: "Would the insulinogenic effect of protein, specifically something like whey protein which causes an insulin response, be something that should automatically refute Taubes arguments about insulins inherent role in increasing adiposity? Second, would overeating on any macronutrient increase insulin simply because you are eating more food (i.e. hypercaloric)?"
9. "Are there best practices for the maximum duration someone should spend in fat loss (or weight gain) phases? Or perhaps an optimal ratio of fat loss phase duration to "maintenance" phase duration? For example, should fat loss phases be for a maximum of 12 weeks followed by maintenance of at least equal duration before resuming a fat loss phase?
10. "I'm a naturally skinny guy who helps other naturally skinny guys bulk up. I think it largely comes down to a blunted pleasure response to food, smaller stomachs, and/or higher NEAT. A lot of us seem to be taller and more thinly built, too. But why do you think things are things so different for us? Why is it so hard to gain weight? And what can we do about it?"

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Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle. But since the 1800's, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas.

Climate change has the potential to negatively impact the nutrient value of plants, soil organisms, food stuffs, via a variety of ways. Climate change puts food supplies at risk. Floods, droughts, more intense hurricanes, heatwaves and wildfires can drive down crop yields, destroy livestock, and interfere with the transport of food. And rising carbon dioxide levels from human activity can make staple crops like rice and wheat less nutritious.

In this podcast the Sigma team take a look at the evidence on how climate change will impact nutrient status, if left unchecked. There will be also a look at what solutions have been put forward to tackle this issue. This episode will focus more on how climate change impacts nutritional & nutrient status, as opposed to converse (but equally important) issue of how food systems impact climate change.

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When it comes to specific questions related to diet and health for women, there is often a shortage of consensus answers from research, for a variety of reasons. In addition, there are clearly aspects of biological sex that have implications for health and also the interaction with diet. For example, the impact of the menstural cycle, of menopause, and differences in nutrient requirements.

In this episode, Dr. Hazel Wallace discusses some of these key considerations. Some things covered include: the impact of menstrual cycle phase on cravings, at-risk nutrients in pre-menopausal women, functional hypothalamic amenorrhea, interaction of diet and PMS, the physiological changes at menopause and potential role of diet.

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This is a preview of the second episode in a new series called "Nutrition Science Explained", in which members of the Sigma team will take a concept commonly mentioned in discussions about nutrition science, and explain what it is, give more background context, and highlight important aspects to know. The goal is to aid listeners to have a deeper understanding of other episodes when such concepts are mentioned.

In this episode Alan Flanagan discusses the concept of the GRADE system, and specifially how it applies to evaluating nutrition research and coming to conclusions for practice.

GRADE (Grading of Recommendations, Assessment, Development and Evaluations) is a framework for developing and presenting summaries of evidence and provides a systematic approach for grading the quality of evidence and making clinical practice recommendations.

In order to listen to the full episode, you will need to subscribe to Sigma Nutrition Premium.

Folate (also known as viatmin B9) actually relates to a collection of folates; both natural dietary folates and synthetic forms, primarily folic acid. This folate/folic acid that is consumed via the diet or supplementation is a precursor for the formation of tetrahydrofolate (THF), which is a carbon donor and acts a cofactor for a number of enzymes that play important roles in several processes.

In this episode, Alan and Danny discuss the role of folate in the methlyation cycle, the impact of folate insufficiency/deficiency, genetics variatnts of the MTHFR gene (and other genes) that impact folate metabolism, and the impact of folate on health outcomes; including heart disease, birth defects, cancer, and brain health & cognition.

Detailed study notes and transcript to this episode

• What is the connection between choline and DHA? What is the PEMT pathway?
• Study design for the choline + DHA trial
• Are there risks of high-dose choline?
• Main findings of the trial
• How DHA status is not just a function of DHA intake, but also methyl metabolism too
• Issues with omega-3 trials; e.g. not taking baseline status into account
• Pragmatic recommendations for health professionals and patients
• Different forms of choline supplements
• Choline supplementation vs. food-derived choline

In this episode Alan and Danny aim to address the idea that you shouldn't eat vegetables, or that they aren't beneficial. We will specifically look at a number of claims that relate to:

1. The claim that vegetables aren't beneficial for health, or that there is no health benefit to high vegetable intake.
2. The claim that vegetables are actually detrimental to health, and their removal improves health.

This episode was orignally published to Sigma Nutrition Premium. If you wish to get more of these Quack Asylum episodes (and lots of other features, including detailed study notes) then subscribe to Sigma Nutrition Premium.

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This is an "ask me anything" (AMA) episode, with Prof. Stuart Phillips of McMaster University. Prof. Phillips takes questions on protein intake, sources, muscle function, and healthy ageing.

To listen to the full AMA, click here to subscribe to Sigma Nutrition Premium.

Questions answered:

• [04.28] What is muscle protein balance?
• [05.32] Why is the focus always on muscle protein synthesis?
• [07.14] Is MPS a good proxy measure for outcomes we care about (e.g. muscle growth/repair)?
• [10.37] What's the difference between 'whole body protein synthesis' and 'muscle protein synthesis'?
• [12.57] We're starting to see commercially available whey that has been produced by bacteria engineered to synthesize whey protein directly from nutritional substrate. It seems like we should expect this to have directly comparable effects given the identical molecular structure. Is there any reason to think this bacterially synthesized whey will have any different effects that whey from dairy?
• [15.50] Does the literature still show that an additional dose of plant-derived protein is required to equate a similar response from animal protein?
• [26.39] During post-exercise conditions does protein ingestion stimulate MPS for longer than the usual 2-3 hour period reported in rested conditions?
• [27.49] Considering the growing interest in fasting protocols (both TRF and longer fasting protocols) - what would you recommend in these circumstances for the preservation / growth of muscle mass. Would it differ between IF/TRF and longer (1-3 day) fasts?
• [34.58] Is it a waste to take too much protein powder at once because some of it won't get absorbed?
• [42.50] Does protein powder lose some of its quality if boiling water is added due to protein denaturation?
• [47.05] Would you please share your opinion about how you evaluate protein status in the body?
• [50.51] I am now over 60 and lift heavy twice a week. What would be a reasonable body fat % for me to aspire to and how much daily protein should I be targetting in my diet?

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Consuming a healthy diet during pregnancy is an obvious and accepted recommedation. However, what exactly is a "healthy diet" in this context? In addition, there are specific nutrients which are crucial for the healthy development of the child, including nutrients which may be difficult to consume enough of. In addition there are nutrients and foods that need to limited or avoided during this period.

In this episode, researcher and dietitian Dr. Julie Abayomi discusses important nutrients in pregnancy (e.g. iodine, DHA, and folic acid), as well as potentially problematic nutrients/foods (e.g. high-mercury fish and caffeine). In addition, she discusses the current debates about weight gain/loss during pregnancy, as well as what supports are needed for health professionals supporting pregnant women.

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It has become common rhetoric for those promoting various types of diets to suggest that dietary guidelines published by government departments are at best, unhealthy, or at worst, causative in driving obesity and chronic disease in the population.

While different countries and organizations produce their own guidelines, with slight differences, most of the conversation has focused on the Dietary Guidelines for Americans, that are created by the USDA.

Often the claims is that following these guidelines actually harms health, rather than promote it. And the guidelines are simply a result of industry forces, long-standing bias, and shoddy science.

But do these claims hold up to scrutiny? In this episode Alan and Danny look at some of the arguments put foward, and take a look at the science underpinning dietary guidelines in a number of countries.

In this episode:

• [0.01.46] Examples of arguments put forward stating that it's not healthy to follow dietary guidelines
• [0.12.50] History of the development of guidelines in the US & narratives around Ancel Keys
• [0.23.50] Misrepresentation of what the guidelines say
• [0.30.49] What are actually in the current Dietary Guidelines for Americans?
• [0.33.10] Changes to guidelines over time
• [0.36.05] Other countries' guidelines: UK, Canada, Nordic countries
• [0.40.50] Investigating the rise in obesity/disease prevalence with the roll out of the guidelines
• [0.56.34] Do people follow the guidelines?
• [1.00.01] The negative role of the food industry
• [1.03.50] Potential issues with dietary guidelines

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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.

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There have been many claims made about the benefits of a detoxification "protocol" or "plan", based on specific dietary and supplemental regimens. Many of the arguments propose that many things we come into contact with are toxins and they can accumulate and compound in effect over time, causing a range of issues. Therefore, by removing these toxins (via a "detoxification protocol"), we can have better health.

And indeed it is well known that there are a large number of toxins in the environment, many of which can potentially be deleterious to health. And it also known that many nutrients are involed in processes of the body's detoxification pathways.

However, is there any evidence that a detoxification diet, plan or "protocol" improves health? Is there any reason to suggest targeting certain nutrients or supplements leads to "better detoxification"? And do we need to avoid non-organic food, toothpaste and non-stick frying plans in avoid to avoid these toxins? This Quack Asylum episode evaluates these claims.

Study notes available at sigmanutrition.com/detox/

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With elevated LDL-cholesterol being a causal risk factor for atherosclerotic heart disease, having interventions to lower blood lipids, and in particular LDL-C, are crucial for population health. A number of drugs are now incredibly effective for this, with statins being the most widely used.

However, for those who do not wish to take a medication and/or have only a mild elevation, there may be potential for dietary intervention to lower LDL-C to a point where a statin (or other drug) is not needed.

A number of aspects of healthy dietary patterns have been known to reduce the liklihood of elevated blood lipids. Most notably perhaps, the ratio of polyunsaturated to saturated fat in the diet (P:S ratio). And an absolute low level of saturated fat in the diet (e.g. < 10% of calories).

However, work by Dr. David Jenkins and collegegues put forward the idea of a "portfolio" of specific nutrients/foods that could additionally lower LDL-C. This became known as the Portfolio Diet. The four primary pillars of this portfolio diet are: soy protein, viscous fibers, nuts, and plant sterols.

In this episode, Danny talks to the originator of this work, Dr. Jenkins.

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Some cognitive decline is normal with age. However, more significant cognitive decline is primarily due to disease-induced dementias (such as Alzheimer's Disease). It also results from neurodegenerative disorders and chronic, prolonged degeneration of our neuronal pathways and functions.

Drug discovery for dementias have been largely unsuccessful, leaving no good treatments for this collection of diseases. This had led to research examining areas that may aid in preventing (or more accurately, slowing) cognitive decline.

In this episode the Sigma team look at the published data on a variety of nutrients, foods and dietary patterns, including: vitamin D, omega-3 fatty acids, B vitamins, caffeine, flavanoids, coffee and green leafy vegetables.

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• [00:02:01] Definitions
• [00:08:40] What causes cognitive decline? Dementia? Mechanisms of ND pathogenesis.
• [00:11:33] Why might nutrition play a role?
• [00:18:18] Dietary patterns
• [00:26:30] Diet interaction with APOE genotype
• [00:31:18] Alcohol
• [00:36:36] Polyphenols - mechanisms
• [00:43:05] Coffee & Caffeine
• [00:45:03] Flavanoids
• [00:51:04] Vitamin D
• [01:04:22] Omega 3 fatty acids
• [01:21:42] B vitamins & green leafy veg
• [01:30:35] Vitamin E
• [01:38:24] How to assess cognitive health in ageing intervention studies
• [01:45:28] Concluding thoughts

Show notes to this episode

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• 02:02 – Framing of the GMOs debate
• 13:52 – Key definitions
• 20:34 – Where do GMOs show up in the food supply? And jurisdiction differences
• 33:40 – Impacts on human health and nutritional differences
• 45:16 – Impact on biodiversity
• 1:01:57 – What's the deal with glyphosate herbicide?
• 1:05:34 – Concluding thoughts

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Coeliac disease is an autoimmune disorder stimulated by the ingestion of gluten, a protein found naturally in wheat, barley and rye. The condition affects approximately 1% of the Western world. However, currently the only approved treatment for coeliac disease is adherence to a gluten-free diet for life.

Therefore there is much research underway to develop alternative treatment options that may help these patients. One novel antigen-focused therapy that has been hypothesised is the use of plant bioactives.

Specifially, in vitro work by Dr. Charlene Van Buiten has looked as whether there is a mechanism by which polyphenols from green tea could be of benefit. Her work shows that these polyphenols can mitigate gliadin-mediated inflammation and intestinal permeability in vitro.

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Current discussions relating to health focus on longevity. This may include some who look at lifespan extension, some who talk of delaying or "treating" ageing or those who focus on reducing morbidity within the parameters of normal lifespan.

One propsed intervention that has garnered a lot of excitement, owing to some interesting research, is the potential use of fasting to increase longevity and/or healthspan. Within this broad category, various different dietary interventions have been suggested, including various forms of intermittent fasting, time-restricted eating, dietary restriction of certain nutritients, calorie restriction or a "fasting-mimicking" diet.

But what does the current evidence tell us? Does the evidence actually match the hype? In this episode Dr. Niamh Aspell, Alan Flanagan and Danny Lennon discuss some of the data on fasting and longevity.

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While dietary guidelines universally include fish as a food group that can be consumed regularly in a healthy dietary pattern, there are some potential risks of fish consumption that get raised. Some have some legitimacy, for example the frequency of consumption of high-mercury fish. However, other claims can go to extremes ("eating fish is bad for you") that are based in ideology rather than evidence.

In this Quack Asylum episode, we use a video made by a medical doctor as an example of where quackery can raise its head on this topic. Specifically, there are four claims made in the video that we investigate and see if there is any basis to them.

This is a Premium-exclusive episode. In order to listen to the full episode and access the show notes, you will need to subscribe to Sigma Nutrition Premium.

Many different diets have been put forward as solutions that treat type 2 diabetes. Some will claim the diet "reverses" diabetes, some say it puts it into "remission", while others more conservatively recommend a diet to manage diabetes symptoms in a healthy way.

There has been some debate on the use of terms like reversal, cure or resolution. And recently more clarity has been found in defining each.

One of the diets that has been recommended by some for the purposes of "reversing" or treating diabetes is a low-fat, whole food plant-based (WFPB) diet. Specifically, there is a claim that it is superior to other diets in treating diabetes. Some of these claims relate to popular online diet & lifestyle programs that use such a diet. While there is also a number of studies that are commonly cited in support of the claims.

In this episode, we evaluate these claims by looking at the published research in this area, across epidemiology, human intervention trials and mechanistic rationale. We also ponder what it means for something to be the "best" diet to treat a chronic disease.

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• 03:15 - Sleep architecture and dimensions of sleep
• 10:29 - Influence of sleep on diet
• 35:11 - Chronotypes
• 53:26 - Impact of diet/meals on sleep
• 59:50 - Supplements like melatonin and tryptophan
• 1:20:27 - Rescuing a poor night's sleep - caffeine and nootropics
• 1:40:31 - Key Ideas segment (Premium only)

Omega-3 fatty acids have long been associated with various health outcomes. A type of omega-3 called alpha-linolenic acid (ALA) is found in various plant foods such as flax seeds or chia seeds. Other omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found typically in marine food sources such as oily fish (e.g. salmon, mackerel) and algae. And while higher intakes of such foods have shown benefit, there has been some confusion over the benefit of such nutrients due to some large omega-3 supplementation trials reporting null findings.

So what should we make of the current evidence base? Does supplementation lead to heart disease risk reduction or not? Do we need direct sources of EPA and DHA in the diet? Does ALA have unique benefits? What is an omega-3 index and why is it important?

In this episode, fatty acid expert Dr. Bill Harris dives into each of these questions and clarifies what the current evidence tells us about the effect of these fatty acids on our health.

Overview:

• 04:02 - Fatty acid definitions/subtypes
• 09:14 - Omega-3 status & the Omega-3 Index (O3I)
• 20:03 - Omega-3 supplementation trials for CVD
• 41:15 - DHA, brain health, cognition in later life, development, etc
• 49:45 - Should we be concerned about omega-6 fatty acids?

Show note available at: sigmanutrition.com/episode432/

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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.

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There is now widespread use of various "artificial sweeteners" in foods and beverages. Most commonly non-nutritive sweeteners are used to sweeten a products, whilst having less sugar and calories than a traditionally sugar-sweetened version of that product. For example, diet drinks (e.g. diet soda) are most commonly associated with artificial sweeteners. However, they are also in a wide variety of food products and supplements.

For a long-time there has been skepticism and alarm raised about their potential health effects. From claims of them increasing our food intake, all the way to causing cancer. And food safety authorities have conducted rigorous examinations of the safety data on each of these compounds.

In this episode, the Sigma team discuss the initial research that raised alarm bells, the current process of safety evaluation for non-nutritive sweeteners, the amounts they are consumed in, and the studies published thus far examining their health impacts.

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1. Vegetables aren't beneficial for health (or that there is no health benefit to high vegetable intake).
2. Vegetables are actually detrimental to health, and their removal improves health.

1. Humans are naturally carnivores, or have evolved to thrive on animal foods, and only turn to plants in times of famine.
2. Certain indigenous populations such as the Inuit or the Masai, eat close to no vegetables, yet have robust health.
3. Many of the nutrients present in vegetables can be obtained from animal foods. And beyond that, these nutrients are more bioavabilable when coming from animal sources.
4. Fibre is not an essential nutrient, and high-fibre diets don't lead to the health benefits that are typically claimed.
5. Certain compounds in plants are actively harmful to us. Some of these compounds are natural pesticides, aimed to hurt us. Others are anti-nutrients, which decrease absorption of other key nutrients.
6. Plants/vegetables contain compounds/nutrients exacerbate clinical conditions such as IBS or autoimmune disorders, and removing all plants including veg, leads to improved outcomes in these people.
7. There is no benefit to a diet high in vegetables compared to a diet with low/no vegetable consumption.

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The popularity of soy foods and soy-based products has been increasing in recent times. This has been particularly the case as a dairy alternative, with people switching to using soy 'milk' and soy-based yogurts and cheese. Additionally, soy has become popular as a meat alternative in a variety of dishes for those looking to reduce meat intake. Soy foods such as tofu can be used in recipes in place of meat, and soy-based 'meat alternatives' that are vegetarian and vegan friendly have been developed.

With this increased prevalence, there has been some debate about the health effects of consuming soy foods and products. On one side, there have potential benefits highlighted of inclusion of soy in the diet. It contains phytoestrogens, which may have beneficial effects. Additionally, it is low in saturated fat, and so is potentially beneficial when used in place of saturated fat-rich foods.

However, some have claimed that the phytoestrogens (isoflavones specifically) in soy can be a cause for concern due to the ability of these compounds to mimic the effects of the hormone oestrogen. One common claim is that high soy intake is detrimental for men particularly, as it is "feminizing"; causing gynecomastia, loss of libido and erectile dysfunction.

So what is the truth? Is soy a health food? A harmful endocrine disruptor? Or simply neutral? In this episode we dive into the research and look at the evidence to date tells us about these questions. We consider two big health outcomes in particular; cardiovascular disease and breast cancer. And then final discuss what this means practically for our dietary choices.

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The pathogenesis of obesity is clearly complex. And the need to have a comprehensive model to explain this pathogenesis is important.

One such model, termed the Energy Balance Model, has largely been the consensus paradigm of obesity scientists to this point. Specifically, a recently published paper in the American Journal of Clinical Nutrition by Dr. Kevin Hall and his colleagues outlined the various nuances of the model, as well as common misconceptions about the model.

However, there are others who propose that this is not the correct model of obesity, but rather that obesity pathogenesis can be better explained by a model called the Carbohydrate-Insulin Model (CIM) of obesity.

While this model has been proposed in various forms over the past couple of decades, the most recently published revision/update of this model was that put forward by Dr. David Ludwig and colleagues, in a Perspective published also in the AJCN, in December of 2021.

In this episode, Dr. Kevin Hall (lead author of the paper mentioned above) and Dr. Stephan Guyenet are on the podcast to discuss the debate surrounding these two models. Specifically, the discussion will focus in on the Hall et al. (2022) and Ludwig et al. (2021) papers, as well as previous work leading up to both.

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Clearly the food choices one makes over time directly impacts health. However, choices are not made in a vacuum; that is, they are not always concious decisions made for rational reasons based on free will. Rather, the choices we make about food are shaped by the contexts within which they are made. The term "food environment" is used to describe the physical, economic, political and socio-cultural contexts in which choices are made about acquiring, preparing and consuming food.

As it was put in a paper published as part of The Lancet series on Obesity (2015), modern food environments "exploit people's biological, psychological, social, and economic vulnerability, making it easier for them to eat unhealthy foods".

In this episode the Sigma team discuss the implications of this, including a discussion of exactly which environmental conditions impact food choices and the evidence that exists for public health policy that may address the problematic aspects of modern food environments.

Topics:

• Intro to food environment [01:47]
• Food preferences [11:50]
• Disposable income/eat well guidelines [39:55]
• What can we do for a healthier population overall? Top down/bottom up [46:14
• Different types of public policy interventions [58:42]
• Stealth interventions [01:07:24]

You can access the show notes to this episode here.

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It's never been more popular to be seen as "evidence-based" as a fitness professional. And indeed evidence-based practice has been seen as the best way to arrive at coaching decisions. But is "evidence-based practice" actually what fitness professionals are doing? Is it even attainable for most coaches? Does it create a burden on them? Does it even matter if you're actually reading reserach or not? What makes for a competent personal trainer?

In this episode, Jacob Schepis is on the show to discuss all these questions and to discuss how he feels evidence-based practice fits within a framework of coaching and coach development.

Show notes can be found at sigmanutrition.com/episode427/

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Jaebien Rosario is currently a graduate level student in public health at East Stroudsburg University. He has degrees in psychology and philosophy, and has previously worked as a personal trainer and nutrition coach. His interest include science denialism, vaccine hesitancy, the philosophy of science, the sociology of science, and meta science.

His current research projects include research proposals for covid-19 and vitamin D trials, research conducted pertaining to local food banks and participation in coalitions for addressing food insecurity in northeast Pennsylvania.

Show notes at sigmanutrition.com/episode426/

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Prof. Anna Krylov is a Professor of Chemistry at the University of Southern California (USC), working in the field of theoretical and computational quantum chemistry. She has a M.Sc. in Chemistry from Moscow State University (1990) and a PhD from The Hebrew University of Jerusalem, Israel (1996).

Krylov is active in the promotion of gender equality in STEM fields, especially in theoretical chemistry. She created the web directory 'Women in Theoretical and Computational Chemistry, Material Science, and Biochemistry'. She has delivered several talks on gender equality in STEM.

In June 2021 she published a paper, "The Peril of Politicizing Science," has received over 75,000 views (as of February 2022) and is the all-time highest-ranked article in the Journal of Physical Chemistry Letters (impact factor of 6.5).

Show notes: sigmanutrition.com/episode425/

In this episode Alan and Danny discuss the role of cholesterol in the body and claims that are made suggesting low levels of blood cholesterol are harmful to health.

Starting with the premise that cholesterol is an important molecule in the body and plays a role in many processes, discussed are two related claims:

1. we should avoid low cholesterol levels as it can harm our health
2. elevated levels of cholesterol may actually be protective against disease or mortality.

The episode also critiques claims about cholesterol being "conditionally essential" and that low LDL-C/ApoB increases risk of mortality, cancer and infection.

Show notes at sigmanutrition.com/episode424/

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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 Sigma Nutrition Premium.

Zoya Huschtscha, PhD is a researcher and assistant lecturer at Monash University (Australia), in the Department of Nutrition and Dietetics. She completed her PhD at the same institution, where her research focused on interventions to prevent and treat sarcopenia; i.e. the loss of muscle function and mass, typically with age. Zoya also has a Masters of Dietetics. In addition to her academic work, she works in private practice as a sports dietitian.

Show notes available at sigmanutrition.com/episode423/

In this episode the Sigma team discuss the research looking at psychobiotics, i.e. probiotics that have health impacts on those with pyschiatric disorders or symptoms. They discuss the origins of the research, the gut-brain axis, mechanisms by which gut microbiota could impact mood, and then the human trials to date that have examined probiotics' effects on mood, anxiety, depression, bipolar disorder and other outcomes.

Show notes can be found at sigmanutrition.com/episode422/ and the Sigma Statement on the gut-brain axis can be found at sigmanutrition.com/gut-brain-axis/

Dr. Brendon Stubbs, PhD, is a Senior Clinical Lecturer and researcher at King's College London, conducting research in physical activity & mental health, the mind-body interface, and meta-research. He has published over 600 academic papers in several leading journals across multiple scientific fields. He has informed policy guidelines in the UK, Europe and the World Health Organization.

Dr. Stubbs is also a clinical physiotherapist, being Head of Physiotherapy at the South London and Maudsley NHS Foundation Trust. He has a MSc in Neurological Rehabilitation & PhD in Pain Medicine & Rehabilitation.

Show notes to this episode are available at sigmanutrition.com/episode421/