Discussions about the science of nutrition, dietetics and health. The podcast that educates through nuanced conversations, exploring evidence and cultivating critical thinking. Hosted by Danny Lennon.
#503: Lyon Diet Heart Study – Canola Oil, “Mediterranean” Diets & Minimizing Bias
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The Lyon Diet Heart Study (LDHS) is often cited as one of the pivotal studies that helped establish the Mediterranean diet as a recognized and recommended dietary pattern for cardiovascular health.
A clinical trial conducted in Lyon, France, the LDHS showed significant reduction in cardiac death could be achieved in secondary prevention patients using a dietary intervention.
Conducted between 1992 to 1996, the study involved 605 participants who had previously experienced a heart attack (myocardial infarction).
LDHS showed an incredible 75% lower risk of cardiac death in these patients. This remarkable reduction was unexpected and led to considerable attention from the medical and scientific communities.
LDHS is interesting to dig into for several reasons. First, it’s clever methodology was able to account for some challenges of doing nutrition research. Second, the dietary intervention, whilst named as a “Mediterranean diet”, should perhaps be considered differently.
In this episode, Alan and Danny dig into all the details, highlighting some important lessons we can take from LDHS.
#502: Sydney Diet-Heart Study – Is Linoleic Acid Causing Heart Disease?
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The Sydney Diet-Heart Study was a clinical trial conducted in the 1960s and 1970s that aimed to examine the hypothesis that reducing saturated fat intake in the diet would lead to a reduced risk of heart disease.
However, it really only gained attention after a more recent re-analysis by Ramsden et al., which in recent years has been used as supporting evidence for the idea that increased polyunsaturated fat (PUFA), and specifically linoleic acid, in addition to reduced saturated fat intake, can increase heart disease risk.
This was based on the findings that substituting linoleic acid in place of saturated fat increased all-cause, CVD and CHD mortality.
This is of course counter to prevailing consensus and guidelines in this area, which routinely show reduced risk on replacing SFA with PUFA.
Could this trial undermine the common conclusions that replacing saturated fat with polyunsaturated fat decreases heart disease risk?
In this episode Alan and Danny discuss some of the crucial aspects to understand about this study and what it means for what conclusions can be made about the impact of PUFA broadly, and linoleic acid specifically, on our health.
Addressing Some Criticisms of Nutritional Epidemiology (SNP 23)
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About This Episode Nutritional epidemiology has faced strong criticism over time. While some of the methodological limitations are fair, often there are criticisms that are misguided and inaccurate.
In this episode, Danny touches on a few examples of the misunderstandings of the field and how such claims can be addressed in a more accurate manner.
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#501: Sex-based Training Recommendations: Evidence-based or Hype? – David Nolan, PhD
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The field of research exploring sex differences in exercise response has yielded intriguing findings, shedding light on the complex interplay between biology, physiology, and training adaptations.
One of the fundamental areas of investigation pertains to sex disparities in strength, power, and hypertrophy. Historically, it’s been well-established that males, on average, exhibit greater absolute strength and muscle mass compared to females. This discrepancy often traces its roots back to inherent physiological distinctions.
However, when it comes to responses to strength and hypertrophy training, the narrative becomes more nuanced. Research indicates that, when individuals of both sexes follow matched resistance training protocols, the relative improvements in strength and hypertrophy are quite similar.
So, do women need to be trained differently than men? The answer, it appears, is not as much as one might assume. The principles of progressive overload, specificity, and other training fundamentals remain constant. While individualization is key, the idea of drastically distinct training guidelines based on sex lacks compelling empirical support.
The guest in this episode, Dr. David Nolan, is a researcher in the area of sex differences in exercise response, and has looked at the influences of menstrual cycle and hormonal contraceptive use in female athletes on their performance.
In this episode, we discuss the research to date, and what this means practically for athletes and coaches.
#500 – The Big Unanswered Questions in Nutrition Science
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SNP17: Is Personalized Nutrition Superior to General Nutrition Advice? 414: Will Machine Learning Overtake Traditional Nutrition Research Methods? 469: Chrononutrition – New Findings & Updated Views About This Episode: To mark the 500th episode of the podcast, Danny and Alan take a look at some of the current outstanding questions in nutrition science, what areas have largely been resolved, and how their own thinking has evolved and changed over time.
This brings them into areas such as personalized nutrition, ultra-processed foods, time-restricted eating, salt & health, and the difference between being “evidence-based” and “reference-based”.
We Discuss: Outstanding questions in nutrition science Personalized nutrition Ultra-prosessed foods (UPFs) Diet-Microbiome-Health Omega-3 Fatty Acids Largely resolved questions Sodium & CVD risk TRE/TRF Macronutrient breakdown & weight loss Evolution in our thinking Epistemology at the forefront “Reference-based” to evidence-based Reading research: understanding “highest quality evidence”
#499: How Sensory Cues Impact Food Choice & Behavior – Prof. Ciarán Forde
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Sensory cues, comprising taste, smell, texture, and appearance, serve as the initial drivers that influence our food preferences and liking for particular items. These sensory cues can be both inherent, such as the natural sweetness of fruit, and learned, as in the association between a particular aroma and a favorite dish.
One crucial aspect of this research is delving into how sensory properties of food, like texture and taste, contribute to our choices and consumption patterns. Food texture, for example, plays a key role in determining how quickly we consume a meal, with softer textures often being associated with faster eating rates.
Sensory intensity and palatability are also central themes in this research. Moreover, research into dietary fat reveals intriguing phenomena like “fat blindness,” where the ability to discriminate different levels of fat diminishes as taste intensity increases. Understanding these relationships can help shed light on factors contributing to overeating and potential avenues for behavior modification.
To give us a better insight into this field of research, Professor in Sensory Science and Eating Behavior at Wageningen University, Prof. Ciarán Forde, is on the podcast to discuss these ideas.
5 reasons why...
Five reasons why Sigma Nutrition with Danny Lennon, MSc.is the best podcast on fitness and nutrition out there!
1) Complete respect for guests
2) Friendly and personable with guests, while never excluding listeners
3) Clear and succinct understanding of guests' topics
4) Razor-sharp ability to demonstrate understanding of any topic guests present, and more importantly reiterate that info in a way that is extremely comprehensible
5) Critical, yet unbiased (science-based) assessment of anything presented
If you want to change your body, listen to this!