Sigma Nutrition Radio

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. Click here for show notes to this episode Click here for Premium Click here for live event details

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

A recently published study by Klatt and colleagues examined the impact of choline supplementation alongside DHA supplementation, versus DHA supplementation alone, on DHA status in pregnancy. It is known that DHA is a critical nutrient at this time for healthy development of the child. And through a number of mechanisms discussed later, it has been hypothesized that choline could lead to greater DHA status. We discuss: 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 Access the show notes here Subscribe to Premium here

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: The claim that vegetables aren't beneficial for health, or that there is no health benefit to high vegetable intake. 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. Click here to access show notes

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? Subscribe to Premium

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. Click here for show notes Subscribe to Premium

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 Links: Subscribe to Premium Show notes to this episode

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/ Subscribe to Premium at sigmanutrition.com/premium/

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. 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. Links: Episode show notes Subscribe to Premium Attend Sigma Conference in Dublin

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. Subscribe to Premium [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 Subscribe to Premium

The issue of genetic enginnering in the food system is one that is often charged with emotion and strong opinion. Indeed, there has been much concern voiced over the years about the potential harms to both human health and the environment of genetically-modified (or more accurately, genetically-engineered) crops. Some concern takes the form of outright hysteria, while other concerns are more nuanced and subtle. Among these concerns, which have good evidence to support them? What regulation is currently in place? Why are their differences between the US and the EU? On the opposite side, there are clear advantages to GE crops; including disease resistance, herbicide tolerance, and even enhanced nutritional content. But are these advantages possible without harm? Do the pros outweigh the cons? In this episode, Alan and Danny discuss the current evidence on genetically engineered crops (or GMOs) and their effect on human health, biodiversity, and the economy. 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 Access show notes for this episode Subscribe to Premium

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. Click here for show notes. Click here to subscribe to Premium.

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. Go to show notes Subscribe to Premium

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. Access show notes Attend Sigma event in Dublin, May 2022 Subscribe to Sigma Nutrition Premium

The relationship between our diet and sleep is bi-directional; i.e. sleep impacts diet and diet impacts sleep. Therefore, we can examine the impact of sleep timing, duration and other dimensions on our dietary intake. And then also examine the impat of both overall diet and specific nutrients on improving/worsening sleep. The is clear evidence of distinct, acute effects of restricted sleep time on food preferences, eating behaviour, energy intake, and our underlying metabolic physiology. When it comes to the ability of certain foods or nutrients to improve sleep, often many claims are based on weak evidence or mechanistic reasoning. But there is evidence showing some impacts of certain compounds to either positively or negatively impact sleep. So what is the accurate way to look at this bi-directional relationship? In this episode, Greg Potter, PhD discusses the evidence to date. Dr. Potter received his PhD from the University of Leeds, where his research focused on circadian rhythms, sleep, nutrition, and metabolism. In this episode: 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) Click here for show notes. Click here to subscribe to Sigma Nutrition PREMIUM.

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/ Subscribe to Sigma Nutrition Premium here: sigmanutrition.com/premium/

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. Access show notes here. Subscribe to Premium here.

In this Premium episode Alan and Danny aim to address the idea that you shouldn't eat vegetables, or that they aren't beneficial. Two related ideas have been circulated in some nutrition/health communities on the internet: Vegetables aren't beneficial for health (or that there is no health benefit to high vegetable intake). Vegetables are actually detrimental to health, and their removal improves health. Such advice is usually defended through some combination of the following claims, which we examine in this episode: Humans are naturally carnivores, or have evolved to thrive on animal foods, and only turn to plants in times of famine. Certain indigenous populations such as the Inuit or the Masai, eat close to no vegetables, yet have robust health. 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. Fibre is not an essential nutrient, and high-fibre diets don't lead to the health benefits that are typically claimed. 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. 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. There is no benefit to a diet high in vegetables compared to a diet with low/no vegetable consumption. Premium subcribers can access the detailed study notes to this episode here. Click here to subcribe to Sigma Nutrition Premium.

Click here to subscribe to Sigma Nutrition Premium 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. Click here for show notes to this episode Click here to subscribe to Sigma Nutrition Premium

Click here to subscribe to Premium 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. Click here to access show notes for this episode Click here to subscribe to Premium

Click here to subscribe to Sigma Nutrition Premium 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. Subscribe to Sigma Nutrition Premium

Subscribe to Sigma Nutrition Premium: https://sigmanutrition.com/premium/ You love listening to, and learning from, nutrition podcasts. Sigma Nutrition Premium allows you to more effectively do that. Understand topics more deeply Retain more of what you hear Recall specific details long after listening Study nutrition science in an enjoyable way As a Premium subscriber you get exclusive access to: Detailed Study Notes 'Key Ideas' Segments Hand-crafted Transcripts Premium-only Episodes Subscribe to Sigma Nutrition Premium: https://sigmanutrition.com/premium/

Subscribe to Sigma Nutrition Premium 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/ Subscribe to Sigma Nutrition PREMIUM to receive Premium-only episodes, bonus segments, and detailed study notes for each episode.

Subscribe to Sigma Nutrition Premium 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/

Subscribe to Sigma Nutrition Premium 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: we should avoid low cholesterol levels as it can harm our health 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/

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/

and the Sigma Statement on the gut-brain axis can be found at " data-userid="424351203778215936" data-orgid="425311536639447040">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. and the Sigma Statement on the gut-brain axis can be found at " data-userid="424351203778215936" data-orgid= "425311536639447040">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/

Kevin Boehnke is a researcher at the University of Michigan, in the Chronic Pain and Fatigue Research Center. His current research focuses on therapeutic applications of illicit or semi-licit substances (cannabis, psychedelics). His goal is to rigorously assess appropriate use of these substances and to help address the public health harms caused by their criminalization. Carrie Cuttler is an Assistant Professor at Washington State University. Her research at the Health and Cognition Laboratory there focuses on elucidating the potentially beneficial and detrimental effects of chronic cannabis use and acute cannabis intoxication. Her recent work has focused on examining links between cannabis use and mental health (e.g., ADHD, PTSD, OCD, depression, anxiety). Show notes available at sigmanutrition.com/episode420/

Dr. Nathan Bryan, PhD is an Adjunct Assistant Professor at Baylor College of Medicine. Dr. Bryan has been involved in nitric oxide research for the past 18 years and has made many seminal discoveries in the field. He was the first to demonstrate and discover an endocrine function of nitric oxide via the formation of S-nitrosoglutathione and inorganic nitrite. Dr. Bryan obtained his doctoral degree from Louisiana State University School of Medicine in Shreveport where he was the recipient of the Dean's Award for Excellence in Research. He pursued his post-doctoral training as a Kirschstein Fellow at Boston University School of Medicine in the Whitaker Cardiovascular Institute. After a two year post-doctoral fellowship, in 2006 Dr. Bryan was recruited to join faculty at the University of Texas Health Science Center at Houston by Ferid Murad, M.D., Ph.D., 1998 Nobel Laureate in Medicine or Physiology. Show notes at sigmanutrition.com/episode419/

Click here to subscribe to Sigma Nutrition Premium In this episode Danny and Alan discuss the debate around whether a direct source of the long-chain omega-3 fatty acid DHA should be recommended. Many people do not consume the marine foods (primarily fatty fish) that contain DHA, and higher DHA intakes, DHA status, and omega-3 indices are predictive of certain health outcomes. But the essential omega-3 fatty acid alpha-linolenic acid (ALA) can be consumed from plant sources. So do those who do not consume direct sources of DHA have lower DHA status? Does this matter? And if so, then what pragmatic conclusions can we come to? All of this is covered in this episode. Show notes available at sigmanutrition.com/episode418/ Click here to subscribe to Sigma Nutrition Premium

Dr. Austin Baraki joins Danny and Alan to critically evaluate the assumption that blood levels of a nutrient directly tell us about overall nutritional status. With many people getting blood tests done outside of clinical settings, there is significant risk of misinterpretation of what these measures mean. In this episode we discuss measures of calcium, sodium, vitamin D and others as examples of where misinterpretation and misunderstanding can happen. Show notes can be found at sigmanutrition.com/episode417/

Dr. David Nunan, PhD is a Lecturer and Senior Research Fellow in the Centre for Evidence-Based Medicine at the University of Oxford. There, he is the Director of the Postgraduate Certificate in 'Teaching Evidence-Based Health Care' and the lead tutor for the internationally-renowned 'Teaching Evidence-Based Medicine' course. He is a principal investigator with research interests in prevention and treatment of lifestyle-related conditions, improving the understanding and use of research evidence, and meta-epidemiology (research on research). David has experience in a breadth of methodologies including diagnostic studies, statistical analysis, qualitative research and clinical trials. Show notes available at sigmanutrition.com/episode416

Bruce Neal is Executive Director at The George Institute for Global Health Australia; and Professor of Medicine, UNSW Sydney. Prof Neal is a UK-trained physician who has 25 years' experience in clinical, epidemiological, and public health research with a focus on heart disease, stroke and diabetes. Bruce has a longstanding interest in high blood pressure and diabetes and the potential for both clinical interventions and changes in the food supply to deliver health gains. His work has been characterised by its focus on collaboration, quantitation, translation and impact. He holds professorial appointments at UNSW Sydney, Imperial College London, and an honorary appointment at the University of Sydney. He has published some 450 scientific papers and since 2016 has been identified by Thomson Reuters as one of 'The World's Most Influential Scientific Minds', an acknowledgement provided to just a few thousand researchers across all disciplines, worldwide. He has particular expertise in the conduct of large-scale clinical trials addressing cardiovascular disease but has also done a significant body of work addressing food policy issues related to sugars, fats, portion size and food labelling. Find the show notes at sigmanutrition.com/episode415/

In this episode, the Sigma team discuss the claim that machine learning and data science may overtake traditional research methods in nutrition. They discuss how machine learning could solve some current limitations of traditional methods, studies on its use so far, potential applications in future trials, and potential limitations or problems with the increased use of data science (including ethical and societal concerns). They also ponder on how tech is currently being used (and abused) in relation to personalised nutrition, tech products, continuous glucose monitoring use, among other things.

" data-userid="424351203778215936" data-orgid= "425311536639447040">Anthony Fardet, PhD is a nutrition science researcher in the Human Nutrition Unit at Université Clermont Auvergne, France. His work has focused on a number of related areas; the consequences of the reductionist and holistic approaches applied to nutrition research, the relevance of a new classification of foods based on their degree of processing, and the role of the complex structure of the food in its health potential ("matrix effect"). You can find the show notes to this episode at sigmanutrition.com/episode413/

" data-userid="424351203778215936" data-orgid= "425311536639447040">Dr. Eirini Dimidi of King's College London discusses the research on diet in chronic constipation and functional bowel disorders. Dr. Dimidi is a Lecturer in Nutritional Sciences and a Registered Dietitian. In 2016, she was appointed as a Research Associate at King's College London, where she undertook several research projects on the impact of nutritional interventions in gut function and dysfunction. " data-userid="424351203778215936" data-orgid= "425311536639447040">Dr. Dimidi is undertaking research on nutrition-based interventions, including fibre, plant foods, prebiotics, probiotics, and the low FODMAP diet, in gastrointestinal health. Her primary focus is to advance the understanding of the impact of dietary therapies in functional bowel disorders, including chronic constipation and irritable bowel syndrome. " data-userid="424351203778215936" data-orgid= "425311536639447040">You can find the show notes to this episode at sigmanutrition.com/episode412/

Click here to subscribe to Sigma Nutrition Premium In this episode Alan and Danny discuss the role of nutrition in bone health. They cover the importance of bone health, bone disorders such as osteoporosis, how nutrients play a role in bone remodelling, and the evidence of dietary and supplementation trials on bone health outcomes. You can find the show notes, with links to all the reference studies, at https://sigmanutrition.com/episode411/ Click here to subscribe to Sigma Nutrition Premium

In this episode Alan and Danny answer a variety of questions sent in from listeners. Questions: [1:10] Gabriel - Is there any benefit to including SFAs and cholesterol in low quantities in our diets for healthspan? [10:42] Luis Arrondo - Can I do 3 rather than 4 meals or more for protein absorption by increasing grams of protein? How many grams of protein can be absorbed at one sitting. Does taking in protein at night help more absorption of protein? If so, something slower, like milk over whey? Last, how much protein per kilo of weight to gain muscle via weightlifing? [19:34] Heather Smith - Please could you go into the sodium needs of those with hypotension. Your podcast about normotension and hypertension was excellent, as was the section relating to athletes. I'd love to hear your thoughts on the sodium needs of a hypotensive person. Thank you! [27:00] Judith Williams - I would find it really helpful if you could summarise what the evidence shows are the key dietary changes for long term weight loss. [36:41] Dale Grant - Great podcast and episode as normal especially the quack asylum (big fan of this segment). Having listened to a few of these extreme people (quacks) on various platforms, I've noticed they also employ an aggressive falsify my opponents position tactic. Its almost as if they are aware of Karl Poppers falsification principle, but have misinterpreted it as falsify my "opponents" position instead of my own. Aside from the fact they falsely view the person they are having a debate with as their "opponent", they miss the point that they should be trying to find evidence to falsify their own position, and thus get closer to a capital T Truth. On the other hand as Alan pointed out with Assem Mahlhotra, this may just be a reluctance to acknowledge evidence for other reasons (narcissism, us vs Them narrative, etc). Nowhere was this more apparent than when James Wilks (host of mass propaganda film game changers), sought to aggressively debate Chris Kresser on the Joe Rogan Podcast. Considering Wilks is a former cage fighter this wasn't surprising. Unfortunately, this aggressive tactic does lead some people to conclude that Wilks has "won" the argument, because he has "won" the debate. Similar to most modern debates, it seems like you don't have to win the debate intellectually with reason. Instead you just have to make it seem as if your more competent than your opponent. Do you agree these extreme people employ this tactic? and how do you think we could improve "scientific" debates (note inverted commas) in the public domain in the future? [46:40] Dimitri - Should fruit consumption be moderated because of the sugar content? For example, a fig has 8g of sugar, can I eat 5-10 in one sitting or would that be detrimental to health? [51:26] Rebecca Toutant - What is the evidence / practice behind integrative and functional nutrition? [56:06] Duncan Clarke - This will be a strange question for you but I'll send it anyway. How could a cyclist specifically lose upper body muscle mass? For example a fit healthy athlete from another sport takes up cycling and they now have more arm/shoulder muscle than needed. The goal being to maximize the power to weight ratio for climbing. [60:15] Gabriel - Do you foresee any public health issues related to the increasing popularity of plant based diets, where less careful individuals may face issues consuming certain nutrients harder to get from a plant based diet, such as preformed Vitamin A, choline, iron, protein etc? [72:03] Ward Stanford - After re-listening to your podcast on weight maintenance over time I was wondering what information exists on the idea of establishing new body fat set points. It seems like merely existing at a lower bf% for a period of time may not be enough, but what are your thoughts on one's ability to truly create a lower set point where it becomes easier to maintain a lower body fat, and how long would you need to be at that lower bf% for it to become a "set point" Thank you!

" data-userid="424351203778215936" data-orgid="425311536639447040">In this episode nutritionist Simon Hill discusses the barriers to eating a healthy diet, steps that can be taken to shift both individuals and the general population to a healthier dietary patten, and a number of other topics. Find the show notes at sigmanutrition.com/episode409/

or you can support the show on " data-userid="424351203778215936" data-orgid= "425311536639447040">Dr. Mario Kratz is a clinical researcher in the areas of nutrition, obesity, and cardiometabolic disease, with more than 20 years of experience running clinical studies in a variety of populations. He is a former research associate professor at the University of Washington in the departments of Medicine and Epidemiology. And is also formerly an Associate Professor at the Fred Hutchinson Cancer Research Center in Washington state. or you can support the show on " data-userid="424351203778215936" data-orgid= "425311536639447040">You can find the show notes at sigmanutrition.com/episode408/ or you can support the show on patreon.com/sigmanutrition/

In this episode we discuss the potential impact of dietary polyphenols on cardiovascular disease risk; including impacts on blood pressure, flow-mediated dilation, and other related outcomes. We talk about some potential mechanisms and then several specific randomized, controlled trials. You can find the show notes at sigmanutrition.com/episode407/ and you can support the podcast on patreon.com/sigmanutrition

In this episode we discuss the potential impact of dietary polyphenols on cognitive health; including cogitnitve funciton, memory, and risk of dementia and Alzeimher's. We talk about some potential mechanisms, cohort studies, and then direct controlled trials. You can find the show notes at sigmanutrition.com/episode406/ and/or support the podcast at patreon.com/sigmanutrition

and you can support the podcast at " data-userid="424351203778215936" data-orgid="425311536639447040">Dr Adrian Brown is a NIHR Lecturer and Research Fellow in the Centre of Obesity Research at University College London. He is also a senior Specialist Weight Management and Bariatric dietitian with over 15 years of clinical experience and a PhD in Medicine from Imperial College London. and you can support the podcast at " data-userid="424351203778215936" data-orgid= "425311536639447040">His research interests centre around obesity, type 2 diabetes, bariatric surgery, weight stigma and the use of formula-based diets in different patient populations. He is an Honorary Academic for Public Health England Obesity and Healthy Weight Team, on the strategic council for APPG on Obesity and is on the scientific council of the British Nutrition Foundation. and you can support the podcast at " data-userid="424351203778215936" data-orgid= "425311536639447040">You can find the show notes to this episode at sigmanutrition.com/episode404/ and you can support the podcast at patreon.com/sigmanutrition/

and you can support the podcast at " data-userid="424351203778215936" data-orgid= "425311536639447040">Prof. Marion Hetherington is Professor of Biopsychology at University of Leeds, where her research is focused on the psychology of appetite across the lifespan. She has previously been at Johns Hopkins, the NIH, the University of Dundee, University of Liverpool and Glasgow Caledonian University, before taking up her role in Leeds in 2008, where she works within the Human Appetite Research Unit. You can find the show notes to this episode at sigmanutrition.com/episode404/ and you can support the podcast at patreon.com/sigmanutrition

" data-userid="424351203778215936" data-orgid= "425311536639447040">Prof. David Jacobs, PhD is Professor of Public Health, in the Division of Epidemiology and Community Health, at the University of Minnesota. He has published highly inflential work in nutritional epidemiology and health epidemiolgy for decades. A number of his papers have brought up crucially important ideas about how to do good nutrition science. Specifically, he has talked about think of whole diet or foods as the exposure of interest, rather than individual nutrients. Essentially warning against the pitfalls of applying a biomedical lens to nutrition research. You can find the show notes to this episode at sigmanutrition.com/episode403/

" data-userid="424351203778215936" data-orgid= "425311536639447040">Prof. Leanne Redman is a Professor of Reproductive Endocrinology & Women's Health, based at the Pennington Biomedical Research Center. As the director of the Reproductive Endocrinology and Women's Health Laboratory, she is focused on understanding the intergenerational transmission of obesity. She has published on maternal diet, preeclampsia, and gestational diabetes, amoung other issues. She and her colleagues are currently conducting a rigorous trial to determine the effects of a 6-month gestational intervention with calorie restriction and food provision to promote maternal weight maintenance and fat loss in 100 pregnant women with grades 2 and 3 obesity. " data-userid="424351203778215936" data-orgid= "425311536639447040">Show notes are available at sigmanutrition.com/episode402/ " data-userid="424351203778215936" data-orgid= "425311536639447040">You can support the podcast at patreon.com/sigmanutrition/