Most people think longevity is about living longer.

Dr. Jack Kreindler thinks that's exactly where we've gone wrong.

The longevity industry has never been bigger. Every week there's a new supplement, a new biomarker, a new biohack, or a new promise that you can slow aging.

But after more than 25 years working with elite athletes, founders, CEOs and patients facing life-threatening disease, Jack has reached a very different conclusion.

The goal isn't to live longer. It's to stay fully alive for as long as possible.

In this episode of Return on Health, hosts Niko Hems and Miguel Medina sit down with one of the world's leading physicians in preventive medicine and human performance to separate evidence from hype.

We explore why Jack has become one of the biggest critics of the word longevity, what he really thinks about Bryan Johnson and David Sinclair, whether NAD boosters actually make sense, and why purpose, relationships and resilience may be more powerful than the latest biohack.

━━━━━👤 ABOUT THE GUEST━━━━━

Dr. Jack Kreindler is a physician, physiologist and entrepreneur specializing in preventive medicine, human performance and healthy aging.

He is the Founder & CEO of WellFounded and previously founded the Centre for Health and Human Performance (CHHP) in London, where he pioneered a model combining elite sports science with clinical medicine.

Over the past two decades, he's worked with Olympic athletes, military personnel, founders, CEOs and patients with complex medical conditions - helping them maximize health, performance and resilience rather than simply adding years to life.

━━━━━🎙️ ABOUT THE HOSTS━━━━━━

Niko Hems

Niko Hems is a longevity expert and Head of Growth at YEARS, a company building a longitudinal, multi-modal health dataset to make prevention personal and data-driven.

Miguel Medina

Miguel Medina is co-host of Return on Health, a podcast built on a simple idea: a system always produces the outcomes it's incentivized to produce - so if we want better health outcomes, we need better incentives.

━━━━━━CHAPTERS━━━━━━

00:00 Why Jack Rejects the Word "Longevity"

01:33 What People Are Really Asking For

03:29 Healthspan vs. Lifespan

08:42 The Pillars That Actually Matter

12:02 What Happens Inside a Longevity Clinic

17:56 The Biomarkers Worth Paying Attention To

19:45 Why Human Connection Might Be the Ultimate Biomarker

28:25 Environmental Toxins & Modern Living

32:50 Are Toxins Really Making Us Sick?

36:14 Bryan Johnson, David Sinclair & Longevity Escape Velocity

40:03 What Founders Can Learn From Elite Performers

44:06 Burnout, Stress & High Performance

47:27 Can We Really Make 90 the New 60?

48:30 The Longevity Supplement Jack Would Never Take

49:40 The Supplements He Actually Recommends

51:15 Will AI Replace Doctors?

52:51 The Biggest Problem With Modern Healthcare

━━━━━💡 KEY QUESTIONS ANSWERED━━━

• Is the longevity industry focusing on the wrong goal?

• Can you actually extend your lifespan - or just your healthspan?• Are expensive longevity supplements worth the money?

• What does Jack really think about Bryan Johnson's Blueprint?

• Which supplements have the strongest evidence today?

• Why is VO₂ Max one of the most powerful predictors of long-term health?

• Are environmental toxins a bigger problem than we realize?

• Can AI become a better doctor than humans?

• Why might relationships, purpose and meaning outperform the latest biohacks?

• What would Jack change about modern healthcare if he could?

Connect with Jack

🌐 WellFoundedhttps://wellfounded.health

🏥 Centre for Health and Human Performance (CHHP)https://chhp.com

💼 LinkedInhttps://www.linkedin.com/in/jackkreindler/

Is the longevity supplement hype real - or are you wasting money? Bestselling author Bas Kast breaks down what actually works in nutrition, supplements, and slow aging.

Most people don't suffer from a lack of health advice. They suffer from too much of it. One expert says eat more protein, the next says cut animal foods. One says supplements are useless, the next sells a 100-pill longevity stack - and all of it sounds convincing.

In this episode of Return on Health, hosts Niko Hems and Miguel Medina sit down with Bas Kast - the science author whose book The Diet Compass (Der Ernährungskompass) sold over 1 million copies - to separate evidence from noise. We cover what still holds up in nutrition science, which supplements are worth taking (and which are pure marketing), why you are never the "average" person in a study, and Bas's new project SlowAger.

━━━━━━━━━━━━━━━

👤 ABOUT THE GUEST

━━━━━━━━━━━━━━━

Bas Kast is a science journalist and bestselling author known for translating complex nutrition and longevity research for a general audience - without academic jargon or wellness hype. His book "The Diet Compass" (Der Ernährungskompass) became an international bestseller with 1M+ copies sold, grounded in thousands of peer-reviewed studies. His newer work focuses on vitamins and supplements (the "Vitamin Compass" / Der Vitamin-Kompass), and his current project, SlowAger, explores the messy intersection of nutrients, supplements and healthy aging.

━━━━━━━━━━━━━━━

🎙️ ABOUT THE HOSTS

━━━━━━━━━━━━━━━

Niko Hems is a longevity expert and Head of Growth at YEARS, a company building a longitudinal, multi-modal health dataset to make prevention personal and data-driven.

Miguel Medina is co-host of Return on Health, a podcast built on a simple idea: a system always produces the outcomes it's incentivized to produce - so if we want better health outcomes, we need better incentives.

━━━━━━━━━━━━━━━

⏱️ CHAPTERS

━━━━━━━━━━━━━━━

00:00 Too much health advice — the real problem with health information

01:18 How Bas Kast got into nutrition: headaches, low-carb & a personal wake-up call

05:15 Where health communication goes wrong: incentives & the Brian Johnson effect

12:19 The 3 principles of healthy eating (Michael Pollan's rule explained)

15:04 What Bas changed his mind on: whole grains, the gluten myth, cheese & intermittent fasting

21:01 Population data vs. personalization: why nutrition averages mislead you

28:28 A data-driven future for nutrition, CGMs & the 10-year Diet Compass update

33:25 The supplement hype: do we really need supplements? (NMN, NR, spermidine, taurine)

44:48 SlowAger, low-dose lithium & how to weigh risk vs. caution

51:06 Lightning round: 3 steps to use supplements intelligently

52:39 The most underrated supplement category (AREDS, lutein & zeaxanthin for eye health)

57:20 Return on Health: the one thing to fix in medicine — treat your body like your teeth

━━━━━━━━━━━━━━━

💡 KEY QUESTIONS ANSWERED

━━━━━━━━━━━━━━━

- Do longevity supplements like NMN, NR and spermidine actually work?

- What are the 3 simple rules for a healthy diet?

- Is gluten bad for you if you're not sensitive?

- Why does the same diet work for one person and fail for another?

- Which supplements are actually backed by strong evidence?

- Is low-dose lithium safe as a supplement?

- Why is the medical system "too reactive" — and how do we fix it?

━━━━━━━━━━━━━━━

🔗 LINKS

━━━━━━━━━━━━━━━

📚 Bas Kast - The Vitamin Compass: https://vitaminkompass.com/

🔔 Subscribe for a new episode every week

Functional Medicine MD: What 5,000+ Patients Taught Him About Root Cause Medicine

In this episode of Return on Health, we speak with Dr. Peter Martin, physician, former CNS pharmacology researcher, and founder of FunMed, one of Europe’s leading functional medicine clinics.

Peter spent around 15 years in pharmacology research before his own burnout pushed him to look beyond the conventional model of symptom control. What started as a personal search for recovery became a data-driven clinical model built around root cause medicine, extensive biomarker testing, gut health, metabolism, and chronic disease prevention.

We talk about what functional medicine actually means, why chronic disease often needs a different care model, and what Peter has learned from treating more than 5,000 patients. He explains why fasting insulin may be one of the most overlooked markers in modern healthcare, how low-grade inflammation is often connected to gut health, and why normal lab results do not always mean someone is truly healthy.

We also get into the controversial parts: large biomarker panels, false positives, red meat, vegan diets, anti-nutrients, carnivore diets, and the weakness of much nutrition research. Peter also shares why he believes functional medicine could become part of the European healthcare system, especially if reimbursement shifts from visits and procedures toward actual health outcomes.

This episode covers:

• What 5,000+ patients taught him

• Why fasting insulin is often missed

• How root cause medicine could change care

Topics discussed:

00:00 Introduction
01:00 What FunMed does differently
02:00 Real-world data from 5,000+ patients
03:30 From CNS pharmacology to functional medicine
07:00 Root cause medicine vs symptom control
10:30 Precision health in Sweden and Germany
15:30 Why FunMed tests around 200 biomarkers
21:00 False positives and the problem with large panels
28:00 Fasting insulin and insulin resistance
31:00 Low-grade inflammation and gut health
35:30 Low-carb and ancestral nutrition
41:00 Vegan diets, nutrient deficiencies, and bio-individuality
49:30 Red meat, nutrition research, and epidemiology
56:00 Functional medicine and insurance coverage
59:00 Rapid fire: biomarkers, magnesium, carnivore diet, healthcare reform

Guest

Dr. Peter Martin

Physician, former CNS pharmacology researcher, founder of FunMed, and one of the leading voices trying to bring functional medicine and precision health into European healthcare.

Guest links

LinkedIn: https://www.linkedin.com/in/peter-martin-31b23342/
FunMed: https://www.funmed.se/?srsltid=AfmBOorlgUNnEK1ba7p_zIxug35sx3YMSq6PmYiufq6xJH1VAQ-EiQc0

Return on Health is available wherever you get your podcasts.

If you enjoyed this episode, leaving a 5-star rating on Spotify helps us bring more honest conversations about health, longevity, and medicine to more people.

Harvard MD: The Peptide Boom Is Here.. But Is Medicine Ready?

In this episode of Return on Health, Niko and Miguel speak with Dr. Anand Vinjamoori, Harvard Medical School and Harvard Business School trained physician, former founding Chief Medical Officer at Modern Age, advisor to Superpower, and founder of Next Generation Medicine.

Together, they discuss why longevity medicine is booming while many companies still struggle to build sustainable businesses, why peptides may become one of the next major waves in health optimization, and why the future of biomarkers will likely require a much more individualized and data-driven approach.

This episode covers:

The peptide boom and why it matters
Why longevity businesses often fail
What biomarkers can and cannot tell us

Dr. Anand explains why the current medical evidence system may be too slow for the next generation of therapies, how real-world data and patient registries could help close the evidence gap, and why biomarkers should be used with nuance rather than treated as absolute truth. He also shares his view on overhyped interventions, the role of exercise, and the cultural differences between American optimization culture and European lifestyle rhythms.

Key topics

Longevity medicine and market timing
The business challenges behind longevity clinics
Customer acquisition and why messaging matters
The rise of peptides in health optimization
Evidence gaps, real-world data, and patient registries
Personalized medicine and individual risk assessment
Biomarkers, multi-omics, and biological individuality
Why HBA1c can be overinterpreted
Exercise as one of the strongest health interventions
Cold plunges and the problem of overapplied hormesis
European lifestyle culture vs. American optimization culture

Chapters

00:00 The Longevity Paradox
01:03 Building Modern Age and the Early Longevity Market
05:04 Personal Motivations Behind Longevity Medicine
07:57 What Patients Actually Want From Longevity Care
11:39 Why Many Longevity Businesses Struggle
15:12 How Customer Preferences Have Changed
18:21 Peptides as the Next Big Wave
19:07 Peptides, Regulation, and Medical Experimentation
24:24 The Evidence Gap in Peptide Use
30:58 Why Medicine Needs Better Risk Assessment
36:59 Biomarkers and Biological Ground Truth
44:20 Multi-Omics and the Future of Measurement
48:35 Which Biomarkers Are Useful — And Which Are Noise?
52:42 Culture, Lifestyle, and Health Optimization
55:45 Lightning Round: Metrics, Interventions, and Healthcare Reform

Guest

Dr. Anand VinjamooriHarvard Medical School and Harvard Business School trained physician, former founding Chief Medical Officer at Modern Age, advisor to Superpower, and founder of Next Generation Medicine.

Guest links

LinkedIn: https://www.linkedin.com/in/vinjamoori/
Next Generation Medicine: https://www.nextgenerationmedicine.co/
Superpower: https://www.linkedin.com/company/superpower/posts/?feedView=all

Listen now

Return on Health is available wherever you get your podcasts.

If you enjoyed this episode, leaving a 5-star rating on Spotify helps us bring more honest conversations about health, longevity, and medicine to more people.

Most people think aging is something that happens later.

In reality, the processes that determine how you age — and whether you stay functional — start decades earlier.

In this episode of Return on Health, we sit down with Roberta Vella Azzopardi, a geriatrician and geroscientist with a PhD in cognitive frailty, to break down what aging actually looks like in clinical practice.

Instead of focusing on single diseases, this conversation zooms out: Why do people lose independence? What really drives decline? And where are the biggest missed opportunities in prevention?

What this episode covers

• Why modern medicine often intervenes too late
• What frailty really means — and why it matters more than age
• How loss of muscle drives metabolic and cognitive decline
• The concept of peak span and why function beats lifespan
• Why hearing loss is one of the biggest overlooked dementia risk factors
• The massive gap in menopause and women’s health care
• What actually works vs. what’s just hype in longevity

Key takeaways

Frailty is best understood as loss of physiological reserves.
When those reserves drop below a certain threshold, even small stressors can lead to long-term decline.

This is why two people at the same age can look completely different clinically — one independent, one dependent.

A major driver of this process is muscle loss.
Muscle is not just about movement. It directly affects metabolic health, insulin sensitivity, and even brain function. The good news: even later in life, resistance training and sufficient protein intake can still improve outcomes.

One of the most underestimated risk factors discussed in this episode is hearing loss.
It contributes to cognitive decline through increased cognitive load, social isolation, and shared vascular mechanisms — yet remains widely underdiagnosed and undertreated.

Another critical blind spot is women’s health, especially around menopause.
Many symptoms are treated in isolation instead of addressing underlying hormonal changes, leading to years of missed intervention opportunities.

Timestamps

(00:00) Introduction & Roberta’s background
(04:30) Frailty explained: vulnerability vs. age
(11:00) Why prevention starts decades earlier
(16:50) Reversing decline: muscle, protein, training
(21:00) Peak span vs. lifespan
(28:30) Menopause and missed diagnoses
(36:30) Dementia prevention & modifiable risks
(37:00) Hearing loss and cognitive decline
(50:00) Busting common aging myths
(55:00) Lightning round insights

Takeaways

• Start investing in your health early — not when problems appear
• Maintain muscle mass through resistance training and protein intake
• Don’t ignore hearing health — it directly impacts brain health
• Look at root causes, not isolated symptoms
• Prevention is not one intervention — it’s a system

Roberta:
https://www.linkedin.com/in/roberta-vella-azzopardi-md-phd-8235878a/

Return on Health:
https://returnonhealth.de/

Niko:
https://www.linkedin.com/in/niko-hems/
https://www.instagram.com/niko_hems
https://nikohems.de/

Miguel:
https://www.linkedin.com/in/miguel-medina-stanivukovic-857b9720b/
https://www.instagram.com/miguelmedinastanivukovic/?hl=en

Karolinska MD PhD: You Feel Healthy. Your Data Disagrees

Most people think they’re healthy.

But biology doesn’t care how you feel.

Long before symptoms show up, your physiology is already shifting.. and most check-ups won’t catch it.

In this episode, we sit down with Natalia Trpchevska (MD, PhD Karolinska, Medical & Scientific Director at AYUN) to break down what longevity medicine actually looks like when applied properly.

We go beyond surface-level optimization and talk about what actually drives risk: mitochondria, metabolic flexibility, genetics, and why most people are already off track without knowing it.

This episode covers:

• Why longevity medicine still struggles in practice
• Mitochondria, NAD+ and optimization myths
• Biohacking and the future of healthcare

Key takeaways:

• Health declines silently — symptoms come late
• Longevity medicine asks: where are you heading biologically?
• The basics still dominate outcomes — most people underestimate them
• The next level is personalization, not more hacks
• Two “healthy” people can have completely different risks
• Mitochondria adapt first — then they start driving dysfunction
• Most mitochondrial interventions are misunderstood
• Genetics gives probabilities, not certainty
• Real optimization = prioritization + sequencing

About Natalia:

Natalia Trpchevska is a medical doctor and holds a PhD in genetics from the Karolinska Institutet.

She is the Medical & Scientific Director at AYUN in Zurich, where she focuses on applying systems biology and layered diagnostics to detect early shifts in physiology — before disease develops.

Her work bridges clinical medicine and research, with a strong emphasis on translating complex biology into actionable interventions.

Timestamps:

00:00 – Introduction & Natalia’s background (Karolinska, genetics → clinic)
03:30 – Why genetics naturally leads into longevity medicine
05:00 – What longevity medicine actually does differently
07:30 – “Physiology before pathology” explained
09:30 – The basics vs. the real next level
11:30 – Same lifestyle, completely different risk profiles
13:30 – APOE4, Lp(a) and personalized strategy
15:00 – Mitochondria: what actually happens as you age
18:30 – When mitochondrial dysfunction becomes clinically relevant
21:00 – Cause vs. consequence: where mitochondria fit in aging
23:30 – How mitochondrial function is actually measured
26:30 – Why isolated tests don’t work (layered diagnostics)
29:00 – What happens after testing: prioritization & sequencing
32:00 – Why “doing everything” doesn’t work
35:00 – IHHT explained: mechanism, benefits, limitations
38:30 – Risks, contraindications & when it backfires
41:00 – Environment vs. lifestyle: what really drives dysfunction
44:00 – The hierarchy: metabolism → inflammation → toxins
47:00 – Why most people focus on the wrong layer
49:30 – What genetics got wrong over the last decade
53:00 – Polygenic risk, probabilities & real-world use
56:00 – Gene–environment interaction: what actually matters
58:30 – Final thoughts: what people still misunderstand about health

Links:

Natalia:
https://www.linkedin.com/in/natalia-trpchevska/
https://www.ayun.ch/

More about Return on Health:
https://returnonhealth.de/

Niko:
https://www.linkedin.com/in/niko-hems/
https://www.instagram.com/niko_hems
https://nikohems.de/

Miguel:
https://www.linkedin.com/in/miguel-medina-stanivukovic-857b9720b/
https://www.instagram.com/miguelmedinastanivukovic/

Rethinking Primary Care and Longevity: Insights with Dr. Takhar. In this episode, Dr. Takhar, UCLA and Harvard trained physician-scientist shares his journey from emergency and internal medicine to building a groundbreaking primary care model focused on human connection, longer physician-patient times, and personalized longevity strategies. We explore how systemic issues hinder patient-centered care and what reforms could make healthcare more effective, preventative, and humane.

Key topics:

• The limitations of conventional healthcare: burnout, bureaucracy, short visits
• The unique model of Primary MD: small panels, extensive diagnostics, longer consultations
• Human connection as a pillar of effective medicine
• The importance of listening and communication skills in healthcare
• Ethical considerations of concierge medicine and access equity
• The role of diagnostics: lipid panels, advanced markers, and their clinical relevance
• Risks, hype, and evidence in emerging longevity interventions
• Future pathways for systemic reform: data, evidence, insurance, and policy shifts
• Lessons from infectious disease training applied to longevity and longevity safety
• The "Mixed Medical Arts" approach: integrating diverse fields for optimal patient outcomes

Timestamps:

• (00:00) - Introduction to Dr. Takhar and the care collision in modern medicine
• (02:07) - Clinical experiences shaping innovative primary care
• (07:12) - The human component in healthcare and systemic barriers
• (10:53) - What primary MD does differently to foster patient trust
• (13:20) - Teaching patients the 'why' behind health decisions
• (14:17) - The vital role of health coaches in adherence and engagement
• (15:32) - The holistic approach combining diagnostics, trust, and relationship
• (18:07) - Addressing ethics and access in concierge-like models
• (19:36) - How to demonstrate value and scalable models
• (22:37) - Overcoming telehealth technical issues in podcast interviews
• (23:58) - The importance of comprehensive, integrated care strategies
• (26:32) - Membership-based care: structure and patient experience
• (27:33) - Ethical considerations of luxury care and future access
• (36:36) - System change: from volume to value and prevention
• (42:48) - Infectious disease background shaping longevity skepticism
• (46:55) - The dangers of hype and unproven interventions
• (50:32) - Bottom-up demand and the future of preventative medicine

More about Return on Health:

https://returnonhealth.de/

Dr. Sukhjit “Sarge” Takhar:

https://www.linkedin.com/in/sukhjit-takhar-md/
https://www.primary-md.com/

Niko:

https://www.linkedin.com/in/niko-hems/
https://www.instagram.com/niko_hems
https://nikohems.de/

Miguel:

https://www.linkedin.com/in/miguel-medina-stanivukovic-857b9720b/
https://www.instagram.com/miguelmedinastanivukovic/?hl=en

This episode underscores the critical need for systems that prioritize genuine human connection, personalized diagnostics, and thoughtful health promotion to advance longevity and overall well-being.

Longevity science is advancing quickly. Healthcare systems are moving much slower.

In this episode, Stanford-trained physician Dr. Hillary Lin explains why prevention, biological age testing, mitochondria, and health optimization often struggle to translate into real clinical practice. We discuss the limits of NAD+ supplementation, the risks around peptides, and why behavioral change still drives most health outcomes.

The conversation also looks at decentralizing healthcare, continuous monitoring, and why many high performers struggle with recovery despite doing “everything right.”

What you’ll learn

• Why longevity science and healthcare are misaligned
• The role mitochondria play in aging and energy
• When NAD+ supplementation can backfire
• Risks around peptides and self-experimentation
• Why behavior change drives most longevity gains
• The future of continuous health monitoring

Topics

00:00 The gap in longevity care
02:17 Hillary Lin’s path into longevity medicine
05:28 Decentralizing healthcare
08:13 Mental health navigation
14:05 Mitochondria and mitophagy
16:45 The NAD+ problem
22:33 High performer bottlenecks
27:20 Behavior change and longevity
30:31 Peptides in longevity medicine
35:02 Continuous healthcare models
46:19 Biological age testing
51:32 The future of healthcare monitoring