David Rönnlid Podcast

🌍 How can we align our lives — and our societies — with our body clocks?

Poor sleep and circadian misalignment don’t just make us tired — they impair several aspects of our metabolic health. I sat down with Jonathan Cedernaes, M.D., Ph.D., and explored what we can do about it: from personal daily habits to systemic policy reforms. Sleep quality and quantity isn’t just about recovery — it’s a public health issue.

We dive deep into:

✅ Daily habits that keep your circadian rhythm aligned

✅ Why sleep timing is as important as sleep duration

✅ How late nights and irregular schedules impair metabolism and long-term health

✅ Policy changes that could protect circadian health at a population level — from school start times to shift work regulations

✅ The promise of circadian science for future treatments and prevention strategies

💡 What do you think matters more for our collective health: better personal habits or policy reforms?

#SleepScience #CircadianHealth #Metabolism #PublicHealth

Sleep science group: https://www.facebook.com/groups/495466987134152/

Connect with Jonathan on social media:

X: https://x.com/jcedernaes

IG: https://www.instagram.com/sleepydrcedernaesclocks/

Episode chapters:

00:00:00 Introduction

00:02:05 Sleep as a Driver of Motivation and Healthy Habits

00:04:15 Weekend Catch-Up Sleep: Benefits and Limits

00:07:50 Sleep, Metabolic Health, and Obesity Links

00:10:13 Sleep Disruption and Neurodegenerative Disease

00:12:53 Mechanisms: How Neurodegeneration Impairs Sleep

00:18:30 Supplements, Exam Stress, and Slow-Wave Sleep

00:20:01 The Body's Master Clock in the Brain: The Suprachiasmatic Nucleus

00:23:20 Light, Retina, and the Body’s Internal Timekeeping

00:43:16 Late-Night Eating and Sleep Quality

00:46:00 Heart Rate Variability: What It Really Tells Us

00:52:10 Short Sleepers, Long Sleepers, and Individual Needs

01:05:22 Circadian Misalignment: Jet Lag and Shift Work

01:19:44 Sleep and Mental Health Connection

01:33:11 Diet Timing, Fasting, and Circadian Rhythm

01:43:52 Exercise After Sleep Loss: Helpful or Harmful?

01:56:20 MicroRNAs, Sleep Loss, and Neurodegeneration Risk

02:14:36 AI, Research, and Sleep Science in the Future

02:22:06 Summary of most important takeaways from the conversation

Most of us think of different types of cholesterol as either “good” or “bad.” But the reality is more complex.

Daniel Elías-López, Endocrinologist, Ph.D, is a Mexican endocrinologist and researcher whose work spans both clinical care and public health. After years of treating patients with obesity, diabetes, and lipid disorders, he saw a limit to what could be achieved in the clinic alone. That realization led him toward research—with work aimed at generating knowledge that could inform prevention and treatment strategies for millions.

In this episode, we discuss:

- Why LDL is only part of the picture

- How elevated cholesterol can remain asymptomatic for years, and why early measurement is important for timely risk detection

- Practical, evidence-based strategies that can help lower risk for cardiovascular events

Rather than claiming to have all the answers, Dr. Daniel Elías-López shares his insights from clinical experience and research —highlighting what’s known, what’s emerging, and why prevention matters.

You can connect with Dr. Daniel Elías-López on LinkedIn: https://www.linkedin.com/in/danieleliasl/ and listen to his podcast in Spanish: https://open.spotify.com/show/31RDgmiIWXQHyHNjgBxeNe?si=6bdf7f42589f4af6

Episode chapters:

00:00:00 - Why lipoproteins are essential for human health

00:07:14 - Research motivation behind studying cholesterol particles

00:14:53 - How lipoprotein particle size affects heart risk

00:22:00 - The main types of cholesterol in the body

00:29:40 - Understanding non-HDL cholesterol and health impacts

00:36:50 - Genetics and their influence on lipid metabolism

00:44:02 - Strategies to improve current cholesterol guidelines

00:51:41 - How cholesterol knowledge translates to clinical practice

00:58:49 - Fasting versus non-fasting lipid blood testing

01:06:29 - What cholesterol levels really tell about health

01:13:40 - Additional lipid markers for cardiovascular assessment

01:20:55 - Current debates in cholesterol research and policy

01:28:30 - Impact of diet on lipid profile and heart health

01:36:10 - Future directions in lipid research and prevention

01:43:55 - Key takeaways and summary of cholesterol insights

Parkinson’s disease is now the fastest-growing neurological disorder in the world — and according to Dr. Ray Dorsey, it’s not just about aging or genetics.

Dr. Dorsey argues that environmental toxins — including certain pesticides, industrial chemicals, and air pollutants — are significant, modifiable risk factors for developing Parkinson’s disease. In this podcast episode, we discuss:

🔬 The evidence linking environmental toxins to Parkinson’s disease

💡 What individuals can do today to reduce their exposure to environmental toxins that research has shown are associated with increased risk for developing Parkinson's disease

🏛 The public health policy changes Dr. Dorsey advocates to address the rapid rise of Parkinson’s disease in today’s society.

Dr. Dorsey's book "The Parkinson's Plan": https://www.amazon.com/Parkinsons-Plan-Path-Prevention-Treatment/dp/1541705386

Episode chapters:

00:00:00 Episode highlight reel

00:02:11 Introducing Dr. Ray Dorsey, Parkinson’s Disease Researcher

00:04:43 Evidence Linking Long-Term Exposure to Trichloroethylene to Neurological Decline

00:08:10 Environmental Contributions to Parkinson’s Beyond Genetics

00:12:37 Communicating Risks Without Overstating the Evidence

00:16:47 Historical Use and Persistence of Paraquat in Agriculture

00:19:20 Testing Options for Potential Parkinson’s-Related Risk Factors

00:21:48 Why Parkinson’s Risk Reduction Remains a Global Challenge

00:24:51 Practical Measures to Limit Environmental Neurotoxins

00:30:40 The Role of Policy in Reducing Harm

00:33:05 How Public Awareness Can Drive Change in Exposure

Louise Hecker, PhD, is a scientist of the cellular mechanisms of aging, such as oxidative stress and endogenous antioxidant enzymes in lung tissue and how such mechanisms influence development of fibrotic lung tissue. During the early phases of this study on the effects of psilocbin on aging in human cells and mice, she was an Associate Professor at Emory University, whereas toward the final data analysis and manuscript preparation, she held the same position at Baylor College of Medicine.The study discussed in this episode investigated psilocybin’s ability to prolong cellular lifespan and reduce oxidative stress in human fibroblasts, and it reported that higher doses extended cellular lifespan dose-dependently by up to 57 %. In aged mice, monthly psilocybin dosing markedly improved survival and even restored fur color and hair growth. Both the cell study and the mouse study suggest that psilocybin targets multiple hallmarks of aging, possibly even reversing some age-related processes.The study, "Psilocybin treatment extends cellular lifespan and improves survival of aged mice": https://www.nature.com/articles/s41514-025-00244-xYou can connect with Dr. Hecker on LinkedIn: https://www.linkedin.com/in/louise-hecker-69ba1915/ and on X: https://x.com/heckerlouise.Episode chapters:00:00:00 Can psilocybin slow cellular aging?

00:03:29 Introducing aging researcher Dr. Louise Hecker

00:08:24 The psilocybin-telomere hypothesis explained

00:10:18 What telomeres are & why they shorten with age

00:17:14 Psilocybin makes old cells "behave" like young cells

00:23:23 Regulatory hurdles of psilocybin research

00:25:54 Checking cancer risk & cell division results

00:30:12 Measuring life extension in cells

00:36:34 Scar tissue, fibroblasts & aging

00:42:25 When to start treatment & dosing of psilocybin for maximum anti-aging effects?

00:46:38 Designing the psilocybin mouse study

00:57:28 Mice live longer & look younger after monthly psilocybin dosing

01:07:44 Unanswered questions & follow-up studies

01:27:44 Implications for chronic diseases

In this episode, neurologist Dr. Alberto Espay shares a bold new vision for treating Alzheimer's—beyond plaques and toward personalized care. We discuss limitations of current drug strategies and the potential of the Cincinnati Cohort Biomarker Program to individualize treatments for patients with neurodegenerative disease.

Find his book Brain Fables here: https://www.amazon.com/Brain-Fables-Neurodegenerative-Diseases-Blueprint/dp/1108744621

References:

#1: β-Amyloid accumulation in the human brain after onenight of sleep deprivation: https://pubmed.ncbi.nlm.nih.gov/29632177/

Episode chapters:

00:00:00 Introduction & Dr. Espay's Neurology Speciality

00:01:05 Cincinnati Cohort Biomarker Program (CCBP) Goal

00:02:04 Placeholder Diagnoses: How we Choose Clinical Labels for Diagnoses

00:05:28 Precision Medicine Goal: Individualized Diagnostics and Treatments

00:08:27 Dr. Espay's Critique of the Amyloid Hypothesis

00:11:42 Lecanemab: Validation of the Amyloid Hypothesis?

00:13:56 On the Toxicity of Amyloid Plaques

00:18:05 Monoclonal Antibody Issues: ARIA, Swelling & Bleeding

00:20:18 Data Presentation vs Manipulation: Relative vs. Absolute Risk Reduction

00:27:52 Interpreting Research Data: Sleep Deprivation & Amyloid Example

00:30:23 Amyloid Structure and Toxicity

00:32:27 Preclinical Anti-Amyloid Trials (4 Studies)

00:36:40 CCBP: A Precision Medicine Research Programme

00:39:06 Developing Divergent & Therapy-Linked Biomarkers

00:43:02 Focus on Biological Subtypes, Not Clinical Diagnoses

00:48:03 CCBP as Exploratory Research: A 'Fishing Expedition'

00:50:50 Identifying Outliers (Uric Acid Example)

00:54:28 Skepticism in Medical Research

00:55:40 About the Book 'Brain Fables'

​Richard E. Cytowic, M.D., is a neurologist and author renowned for revitalizing the scientific study of synesthesia. His influential works, such as "Synesthesia: A Union of the Senses" and "The Man Who Tasted Shapes," have significantly contributed to our understanding of this perceptual phenomenon.

​His latest book, "Your Stone Age Brain in the Screen Age: Coping with Digital Distraction and Sensory Overload", explains how our relatively unchanged Stone Age brains struggle to adapt to the rapid advancements of the digital era. From this conversation, you can expect insights into the effects of excessive screen exposure and phone use on the brain and the mind, as well as methods for intentful phone use.

The book: Your Stone Age Brain in the Screen Age: https://www.amazon.com/Your-Stone-Age-Brain-Screen/dp/0262049007

Richard's website: https://cytowic.net/

00:00 - Introduction by Richard Cytowic on Screens and the Brain.

01:06 - The reel scroll social media feature is likened to a slot machine, exploiting our reward system.

04:32 - Unlike eating, screens offer no natural cue to cease engagement

08:34 - Screens Distractions in Everyday Situations and Public Spaces.

14:50 - Negative Impact of Screens On Young People, Including Social Isolation.

18:50 - Parental Screen Use to Pacify Children May Cause Developmental Issues?

27:50 - Passive Screen Use VS Active Engagement in Learning Material for Developing Skills and Knowledge?

35:50 - Brain Regions Involved in Phone Use.

43:86 - Attention Problems and Reduced Socializing as a Result Of Excessive Screen Time.

52:30 - Awareness of the Problem is the First Step to Managing Screen Dependence.

01:04 - Excessive Screen Use Decreases Empathy?

01:12 - Invasive Advertising on Public Screens Forces Visual Attentional Shifts?

01:19 - Our Brains Are Evolved in a Stone Age Environment and Struggle with Today's Stimuli.

01:32 - The Value of Silence in a World of Constant Stimulation.

01:39 - Taking Walks Without a Phone to Enhance Creativity.

Ilya Bragin, M.D., is a double board-certified Neurologist and Interventional Pain Specialist focused on expanding neurological care and brain longevity. He specializes in stroke care, telemedicine, and neurodegenerative diseases.

Connect with Ilya on LinkedIn: https://www.linkedin.com/in/ilya-bragin-b8698b49/

Episode chapters:

00:00 - Introduction & Definition of Telemedicine

03:36 - Important Factors for Effective Telemedicine & Suitable Specialties

06:45 - The Concept of Certified Examination Assistants in Telemedicine

14:53 - Who Can Become a Certified Examination Assistant?

17:42 - AI and Computer Vision in Telemedicine

20:49 - Cost Aspects of Training Examination Assistants

34:12 - Home Monitoring and Wearable Technology for Early Detection and Prevention of Diseases

39:47 - Telemedicine in Underserved Areas

41:41 - Impact of the COVID-19 Pandemic on Telemedicine

50:43 - Telemedicine in Stroke Care

56:26 - Other Neurological Conditions and Telemedicine

01:07:25 - Distance-Based Preventive Medicine

In this conversation, I speak with Matthew Wall, PhD, about the effects of psilocybin and other classic psychedelics on the human brain.

Matthew Wall is a psychologist specializing in psychedelics and functional MRI (fMRI) neuroimaging. He earned his PhD in Cognitive and Brain Sciences from the University of Cambridge. Currently, he leads MRI Applications at Perceptive London and serves as an Honorary Senior Lecturer at Imperial College London.

Learn more about Matthew Wall's work: https://profiles.imperial.ac.uk/matthew.wall

Episode chapters:

00:00:00 Defining "Classic" Psychedelics: Psilocybin, LSD, DMT, and Mescaline

00:02:47 How Matthew Wall Got Involved in Psychedelic Research and His Motivations

00:09:00 Effectiveness of Psilocybin for Treatment-Resistant Depression

00:16:40 Insights from Larger Clinical Trials on Psilocybin's Effect on Depressive Symptoms

00:22:32 Comparing the Acute and Sustained Effects of Psychedelics vs. SSRIs for Depression

00:32:12 Understanding fMRI, Resting State Functional Connectivity (RSFC), and Arterial Spin Labeling

00:39:59 The Acute Effects of Classic Psychedelics on Global and Modular Brain Network Integration

00:47:57 Potential Risks, the Importance of Psychotherapy in Psychedelic Treatment, and Reopening Critical Learning Periods

01:07:48 Effects of Psychedelics on the Default Mode Network (DMN) and Other Key Brain Areas Like the Amygdala

01:33:36 Long-Term Effects of Psilocybin on Personality and The Future of Psychedelic Therapy

Dag Sehlin, PhD, is an Associate Professor of Neurobiology at Uppsala University. His research focuses on Alzheimer’s disease, developing therapeutic and diagnostic tools, including engineered antibodies targeting amyloid-beta

Dag has played an important role in the research behind the development of Lecanemab, an amyloid-beta antibody recently approved for Alzheimer's treatment by both the FDA in the U.S. and the EMA in Europe.

Episode timestamps:

00:00 - Guest Introduction: Dag Sehlin, Associate Professor of Neurobiology

03:25 - Progression of Alzheimer's Disease in the Brain

05:48 - Comorbidities and Challenges in Diagnosing Alzheimer's

12:54 - Tau and Amyloid Beta Markers in Cerebrospinal Fluid

17:00 - Future Potential of Blood Tau for Early Alzheimer's Detection

24:01 - FDA & EMA Approval of Lecanemab for Alzheimer's Treatment

25:27 - Lecanemab: First Disease-Modifying Alzheimer's Treatment

35:23 - Clinical Benefits of Lecanemab Beyond Cognitive Function (Quality of Life, Hospitalization Rates and More)

58:39 - Dose-Dependent Side Effects and Future Improvements

01:00:54 - Transferrin Receptor "Trojan Horse" Mechanism for Blood-Brain Barrier Penetration

01:15:16 - Neuroinflammation: Beneficial vs. Harmful Effects and Possible Solutions

01:39:37 - AI and Brain Imaging: Enhancing Precision

01:42:04 - Enhancing Collaboration Between Academia and Big Pharma Companies

Dr. Mathieu Nedelec, who holds a PhD in sports science, is a researcher specializing in recovery and sleep at the French Institute of Sport (INSEP). His primary research focuses on fatigue, recovery, and evidence-based recovery strategies such as sleep, cold water immersion, and nutrition. He also offers sports science support to elite athletes across various disciplines.

Link to Mathieu's book (available in French).

Episode chapters:

00:00 Introduction

00:25 Why Recovery from Exercise is Important

02:10 Ways to Measure Recovery Including Heart Rate Variability (HRV)

06:02 Consumer Devices and Apps for Sleep Tracking

08:48 How Mathieu Measures Sleep in Elite Athletes

21:00 The Recovery Pyramid: A Hierarchy of Recovery Strategies: Sleep, Nutrition, and Cold Water Immersion as the Foundation

26:30 Key evidence-based nutritional strategies for enhancing recovery: Tryptophan, Gut Microbiome, High Glycemic Index Foods

38:40 Personality Traits and Sleep in Athletes - Neuroticism, Conscientiousness, and Sleep Quality

44:42 How to Use Cold Water Immersion to Enhance Recovery from Exercise