The Vitality Lab Podcast

Testosterone has become the hormone men blame for everything — low energy, stalled progress in the gym, middle age itself. Prof. Channa Jayasena, Consultant in Reproductive Endocrinology & Andrology at Imperial College London, thinks we've got the causality backwards.In this episode we cover why testosterone is a readout of your health rather than a lever to pull on it; why there's no clean cut-off between "normal" and "low"; and what the European Male Ageing Study actually found (only 2% of men aged 40–80 had low testosterone causing symptoms — almost all of them with comorbidities).We also get into the harder stuff: what anabolic steroids do across the three main clusters of harm — reproductive, cardiometabolic and neuropsychiatric — including a Danish registry finding of a threefold increase in mortality in young men, comparable to cocaine use. Why recovery of sperm production can take anywhere from three months to three years after coming off. Why sperm counts have fallen roughly 55% since 1970, and why Channa suspects the steroid effect hasn't even shown up in the data yet.Plus: why detection and testing at grassroots level is the wrong battle, what body dysmorphia and the "Love Island effect" are doing to young men, why the supplement aisle (Tongkat Ali, zinc, magnesium) is a dead end, and the three clinical signs — morning erections, libido, erectile function — that Channa argues should be men's equivalent of a menstrual cycle as a health biomarker.

Professor Paolo Deluca (King's College London, Institute of Psychiatry, Psychology & Neuroscience) has spent over 25 years researching addiction — from the emergence of unregulated synthetic substances sold online, to his current work developing VR-based treatment tools paired with wearable sensors that can help identify craving episodes in real time.In this conversation, we explore how classical conditioning (think Pavlov's dogs) explains why certain environments and cues trigger cravings, how his team is using virtual reality to help people build resistance to those triggers in a controlled, supportive setting, and how wearable technology could one day give clinicians earlier warning signs during recovery. We also discuss the current landscape of addiction treatment in the UK, the importance of treating addiction as a long-term, multi-factor condition rather than a short-term fix, and what gives Professor Deluca hope for the field going forward.This episode is an academic and research-focused discussion. It does not provide medical advice, and nothing discussed should be used as guidance for personal drug use. If you or someone you know is struggling with substance use, please reach out to a licensed healthcare provider or a support service such as SAMHSA's National Helpline (1-800-662-4357, US) or FRANK (0300 123 6600, UK).Topics covered:How craving works, psychologically and physiologicallyVirtual reality as a tool in addiction treatment researchWearable technology and real-time monitoring in recovery supportWhy addiction treatment requires a long-term, holistic approachThe current state of addiction research and where it's headed

Serial entrepreneur David Shaikh — co-founder of Sherwood Sciences — joins the show to talk about building "impact startups," the €5.7M EU-funded app he's developing to diagnose skin neglected tropical diseases (NTDs) like leprosy and Buruli ulcer across Africa, and two decades of lessons learned from ticketing marketplaces to healthcare tech.We dig into how deep convolutional neural networks are being trained on dermatologist-labeled images to help frontline health workers catch these diseases early, the challenges of building a bias-free, skin-tone-inclusive dataset across five African countries, and why the project will be fully open source and eventually handed to the WHO. David also opens up candidly about rejection, bootstrapping before chasing VC money, and how to find your "life mission" without burning out in your 20s.Topics covered:What makes a startup an "impact startup" vs. a traditional oneInside the SkinNTD app: how AI-assisted diagnosis works for frontline health workersBuilding a diverse, unbiased medical imaging dataset in Senegal, Kenya, Ethiopia, Nigeria & DRCWhy the app enhances doctors rather than replacing themRaising non-dilutive funding through Horizon Europe and the WHOHandling rejection, bootstrapping vs. VCs, and finding purpose in your 20s

How does the brain build memory — and why does reward reshape what we remember?In this episode, I sit down with Marielena Sosa to discuss her postdoctoral research at Stanford University, where she studied how the hippocampus encodes space, context, and reward to construct cognitive maps of experience.Dr. Sosa is now a Principal Investigator at University of Colorado Boulder, leading a lab focused on the neural mechanisms of memory and prediction.We explore:– Why memory is not passive storage but active prediction – How reward reorganizes neural representations – The relationship between spatial coding and value – What deteriorates in aging and Alzheimer’s disease – Whether music and dance can engage compensatory circuits in Parkinson’s diseaseThis conversation moves from fundamental systems neuroscience to broader questions about neurodegeneration, plasticity, and how the brain continuously updates its internal model of the world.

In this episode, we go beyond genetic and molecular narratives of Parkinson’s disease to explore a bold new frontier: the role of the microbiome as a biomarker, bystander, or therapeutic target in cognitive decline. My guest today is Dr Frederick Clasen, Research Associate at the Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King’s College London. Dr Clasen completed his undergraduate and master’s work in Bioinformatics and Biotechnology at the University of Pretoria before earning his PhD across the Francis Crick Institute and King’s College London, where he developed mathematical and genome-scale models of host and microbial metabolism.Dr Clasen is first author on a landmark 2025 study published in Gut Microbes that used shotgun metagenomics and machine learning to map both oral and gut microbiome changes across healthy controls and Parkinson’s patients with varying degrees of cognitive impairment. Their work reveals that microbes — and specifically oral microbes translocating to the gut with enriched virulence factors — may be linked to Parkinson’s cognitive decline via an oral-gut-brain axis, offering not just associations but mechanistic hypotheses and potential biomarkers.In this conversation we unpack:Why the microbiome may be more than a bystander in Parkinson’s diseaseWhat makes a microbial biomarker credible vs. noiseHow virulence factors and host metabolism may influence brain functionWhat it takes to move from correlation to testable mechanismThe real hurdles — and opportunities — for translating microbiome science into diagnostics and therapiesIf you’re a scientist, clinician, founder, or investor curious about where biology meets translation, this episode will sharpen how you think about mechanism, de-risking, and what truly counts as a target in complex human disease.

Professor Clare Bryant is a Professor of Innate Immunity at the University of Cambridge and one of the world’s leading experts on inflammation, inflammasomes, and immune signalling. Her work focuses on how the immune system detects danger — from infections to misfolded proteins — and how chronic inflammation contributes to ageing and neurodegenerative disease. Her research has helped shape our understanding of the NLRP3 inflammasome, a key inflammatory pathway now implicated in conditions such as Alzheimer’s disease, Parkinson’s disease, obesity, cardiovascular disease, and atherosclerosis.In this episode, we explore what inflammation actually is, why we need it to survive — and when it quietly turns from protector to problem.We unpack:Why chronic inflammation (“inflammaging”) rises with ageHow inflammatory pathways are linked to brain health and neurodegenerationWhat the NLRP3 inflammasome is — explained simplyWhy fasting produces surprising changes in inflammatory markersHow a lipid called arachidonic acid can switch off inflammasome activityWhy common drugs like aspirin and ibuprofen may have anti-inflammatory effects beyond pain reliefWhether fasting could realistically play a role in managing chronic inflammationThe difference between mouse studies and human biology, and why it mattersWhy biomarkers like ASC “specks” may be more useful than lifestyle hypeThis is a deep but accessible conversation about fasting, inflammation, and brain health, grounded in human data and real biology — not wellness trends. We also discuss the limits of fasting, potential risks, and why personalised approaches to diet and inflammation will likely define the future.If you’re interested in longevity, neuroscience, immune biology, or how lifestyle intersects with disease risk, this episode will change how you think about inflammation.

What role do pets really play in mental health?In this episode, I’m joined by Helen Brooks, Professor of Health and Psychosocial Wellbeing and Mental Health Research Group Lead at the School of Nursing, Midwifery and Social Work. Helen is also Programme Director for the MSc in Clinical Research and has spent years studying how people manage mental and physical illness in everyday life.We explore her research on pets and companion animals as emotional anchors — not as therapy tools, but as sources of presence, routine, purpose, and non-judgemental support.We talk about:Why animals provide emotional safety when humans sometimes can’tHow pets reduce isolation, intrusive thoughts, and despairPurpose, responsibility, and behavioural activationIdentity, continuity, and dignity after a mental health diagnosisWhy grief after losing a pet is often misunderstoodThe risks, limits, and ethical realities of pet-based supportWhat healthcare systems still fail to recognise about human–animal bondsThis is a conversation about co-regulation, trust, silence, and presence — and what animals quietly teach us about how to support one another when words fail.Whether you’re a pet owner, struggling with your mental health, or simply curious about how connection really works, this episode will change how you think about companionship.

Dr Blake Stobie is the Lead Consultant Clinical Psychologist and Director at the Centre for Anxiety Disorders and Trauma (CADAT) in London. With over 25 years of experience treating anxiety, obsessive-compulsive disorder, PTSD and related conditions, Dr Stobie blends deep clinical insight with a warm, evidence-based approach to understanding the mind.We dive into the surprising truth about intrusive thoughts, what they really tell us about how our mind works, and why nearly everyone experiences them — even if they feel bizarre or upsetting. Dr Stobie reframes these thoughts not as flaws or warnings, but as a normal part of human cognition, and shows how anxiety and rumination can take over when we give too much weight to the stories we tell ourselves.If you’ve ever felt pulled into a spiral of worry or wondered why your brain seems to “spam” you with distressing ideas, this conversation offers clarity, compassion, and a path toward breaking the loop.

Dr Riccardo De Giorgi, MD, DPhil, MRCPsych, is a Clinical Lecturer in Psychiatry at the University of Oxford and an Honorary Consultant in General Adult Psychiatry at Oxford Health NHS Foundation Trust. He teaches psychiatry and psychopharmacology, leads experimental medicine research, and focuses on repurposing immuno-metabolic drugs — including GLP-1 receptor agonists — for cognitive and mental disorders. In this episode, we explore GLP-1 receptor agonists (GLP-1RAs) — medications originally developed for diabetes and obesity — and their emerging relevance to psychiatry and brain health. Recent analyses, including work led by Dr De Giorgi, review preclinical and clinical evidence suggesting these drugs may influence cognitive processes, reward pathways, mood regulation, and inflammatory mechanisms implicated in conditions such as depression, addiction, Alzheimer’s disease, and other psychiatric or neurocognitive disorders. We discuss:How GLP-1 signalling works in the body and the brainWhy psychiatrists are increasingly interested in GLP-1RAs beyond metabolic effectsThe current evidence for psychiatric and cognitive benefits (and limitations)Mechanistic challenges in translating animal findings to humansThe importance of stratifying patients and integrating biomarkers in future researchThis episode strips away hype to uncover what science currently supports — and what remains an open question — about the psychiatric potential of GLP-1 receptor agonists.

Professor Luigi Nibali is an award-winning specialist periodontist who has been keeping gums healthy and saving teeth for more than 15 years. He is a Professor of Periodontology at King’s College London (Guy’s Hospital) and a leading clinician–scientist in gum disease and oral inflammation.Trained in dentistry in Italy, Luigi Nibali completed an MSc and PhD at the UCL Eastman Dental Institute, where his research focused on the genetic and inflammatory drivers of aggressive periodontitis. His work spans clinical periodontology, systemic inflammation, and the links between oral health and cardiovascular disease, diabetes, cancer, and neurodegeneration.In this episode, we break down what periodontitis actually is, why it often develops silently, and why bleeding gums are an early warning sign that shouldn’t be ignored. We explore how chronic oral inflammation can contribute to whole-body inflammation, including its relationship with markers such as C-reactive protein (CRP).We then discuss Luigi’s recent feasibility study using a fasting-mimicking diet alongside standard periodontal treatment — what the protocol involved, what they observed, and why diet may help regulate inflammation without adding more medication.This conversation connects oral health, diet, inflammation, and long-term disease risk, with practical insights on prevention and why gum health remains one of the most overlooked pillars of overall health.Highlights • Bleeding gums aren’t normal — they signal chronic inflammation • Periodontitis often progresses silently for years • Oral inflammation can increase systemic inflammatory burden (CRP) • Diet quality may influence gum disease severity • Fasting-mimicking diets show early promise as an adjunct therapyTopics Periodontitis • Oral inflammation • Systemic inflammation • CRP Oral microbiome • Fasting-mimicking diets • Diet & inflammation • Prevention & oral hygiene • Lifestyle and metabolic health