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 physiologically
• Virtual reality as a tool in addiction treatment research
• Wearable technology and real-time monitoring in recovery support
• Why addiction treatment requires a long-term, holistic approach
• The 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 one
• Inside the SkinNTD app: how AI-assisted diagnosis works for frontline health workers
• Building a diverse, unbiased medical imaging dataset in Senegal, Kenya, Ethiopia, Nigeria & DRC
• Why the app enhances doctors rather than replacing them
• Raising non-dilutive funding through Horizon Europe and the WHO
• Handling rejection, bootstrapping vs. VCs, and finding purpose in your 20s

Neuroscientist Professor Ellie Dommett joins Aaran to break down what's actually happening inside the ADHD brain — from the role of the prefrontal cortex and amygdala to the real story behind dopamine dysregulation, attention, and impulsivity.

They explore why ADHD isn't simply an "attention deficit," how it connects to risk-taking, addiction, and exercise (including ultrarunning as a form of self-management), and why moderation can be harder to find for some people with ADHD. Professor Dommett also discusses cultural differences in treatment approaches worldwide, the ongoing debate around medication versus behavioral strategies, and an underexplored frontier in the field: how female reproductive hormones and menopause may shape ADHD symptoms and late-life diagnosis.

A science-first conversation that moves past stereotypes to explain what ADHD really looks like in the brain and in daily life.

"I don't think there should be any shame or judgment around alcohol use during any period" — psychologist Dr. Abi Rose has spent over 20 years researching alcohol, with a recent focus on women through fertility, pregnancy, motherhood, and menopause.

In this conversation, we explore what actually drives maternal drinking — the hormonal shifts in estrogen, progesterone and cortisol during pregnancy and postpartum, and how alcohol can become tied up with identity, social bonding, and coping with stress and sleep deprivation. Dr. Rose walks through the evidence on fetal alcohol spectrum disorder, why fear-based health messaging often doesn't work, and what genuinely helps when women want support.

This isn't a conversation about telling anyone what to do — it's about curiosity before judgment, and understanding the biological, psychological and social reasons behind the choices people make.

What do elite athletes and coaches actually think during performance?

In this episode, I sit down with Amy Whitehead to explore the Think Aloud method, a powerful tool used in sport psychology to capture real-time thought processes during performance.

We discuss how self-talk shapes decision-making, how pressure alters cognition, and why reflection and awareness are critical for high-level performance. The conversation also explores how athletes and coaches can train their minds to regulate emotions, improve focus, and perform under pressure.

We go into the different levels of Think Aloud, how it is used differently by athletes and coaches, and how internal dialogue connects to identity, behavior and performance. We also touch on how fatigue and stress influence thinking, and how simple strategies like reframing and awareness can shift performance in real time.

If you're interested in performance, psychology, or understanding how the mind works under pressure, this episode will give you a practical and insightful perspective.

What does it take to win €5 million to build open-source AI for global health?

In this episode, I sit down with David Shaikh — founder of Sherwood Sciences — to unpack how he secured major European funding to build an AI-powered app designed to help frontline health workers diagnose neglected tropical skin diseases across Sub-Saharan Africa.

We go deep into:

• Why the hardest part of AI isn’t the model — it’s the data

• Building the largest skin NTD dataset ever collected

• Bias in medical AI and why skin tone matters

• Why this project is fully open-source

• What it really means to build an “impact startup”

• Why raising VC isn’t always the right move

• Entrepreneurship, rejection, delusion, and betting on yourself

This isn’t about AI replacing doctors.

It’s about giving healthcare workers leverage — in regions where there is one dermatologist for millions of people.

We also explore the philosophical side of building: how to handle failure, how to think about money vs impact, and why your 20s are for exploration — not pressure.

If you’re interested in AI, global health, startups, or building something that actually matters — this one’s for you.

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 disease

This 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 complex fields like biotech and health, technical brilliance isn’t enough.

Judgment, psychological flexibility, and the ability to operate under uncertainty often determine who adapts — and who collapses.

In this episode, Dr. Alexandra Ilieva, philosopher and Teaching Associate in Buddhist Studies at the University of Cambridge, joins The Vitality Lab to explore how ideas from Madhyamaka Buddhism and contemporary pragmatism can function as practical tools for thinking clearly under pressure.

We examine:

• Why attaching identity to outcomes distorts judgment
• How the “voice in your head” shapes perception and decision-making
• Why over-identifying with views makes disagreement feel existential
• The difference between discovering yourself and constructing yourself
• How loosening attachment to labels can restore agency

This conversation isn’t therapy. It’s about internal architecture.

If innovation requires navigating ambiguity, failure, and disagreement, then how we relate to identity, language, and ego becomes part of the translational process itself.

Because before ideas move from lab to world, they move through a mind.

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 disease
• What makes a microbial biomarker credible vs. noise
• How virulence factors and host metabolism may influence brain function
• What it takes to move from correlation to testable mechanism
• The real hurdles — and opportunities — for translating microbiome science into diagnostics and therapies

If 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.