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In this "Ask Me Anything" (AMA) episode, Peter explores how to think critically about medications and supplements by focusing not on whether an intervention is inherently "good" or "bad," but on whether it makes sense for a specific person with a specific problem. He explains why clearly defining the problem matters more than choosing the intervention itself, how the intended purpose of a medication or supplement should influence the standard of evidence required, and why mechanistic reasoning alone is rarely enough to justify taking something. Peter also examines how baseline risk shapes the true benefit of an intervention, why relative risk statistics can be misleading without proper context, and how to weigh not only side effects, but also cost, inconvenience, and opportunity cost when deciding whether something is worth taking. Additionally, he discusses practical ways to evaluate whether a supplement is actually having a meaningful effect, how to think about discontinuing therapies, why supplements deserve far more skepticism than they often receive, and the small group of over-the-counter supplements he believes may offer a reasonable risk-reward trade-off.

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We discuss:

• How to properly define health problems before considering medications or supplements [1:45];
• How the intended purpose of an intervention should determine evidence standards and risk tolerance [5:00];
• Understanding the hierarchy of evidence for medications and supplements and avoiding the mistake of treating weak evidence as clinical proof [9:00];
• Why mechanistic explanations can be misleading when evaluating longevity interventions [13:15];
• How baseline risk—and the distinction between relative and absolute risk reduction—changes the real-world benefit of medications and supplements [18:15];
• Thinking beyond side effects: the many forms of downside associated with medications and supplements [22:45];
• Why medications and supplements require different standards of trust and evidence [26:00];
• How to structure meaningful self-experiments with medications and supplements to determine if it's they're working [30:30];
• How to monitor the effects of medications and supplements without fooling yourself [32:30];
• How to periodically reevaluate and potentially discontinue medications and supplements [35:15];
• The biggest risks and failure modes of over-the-counter supplements: efficacy, poor quality control, contamination, interactions, toxicity, and marketing-driven overuse [38:30];
• Why the US supplement regulatory system creates unreliable products [41:45];
• A practical framework for evaluating medications and supplements [46:30];
• Over-the-counter supplements with the best balance of evidence and low downside risk [48:00]; and
• More.

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In this episode, Peter explores the complex and often misunderstood world of genetic testing, building a practical framework for understanding what these tests can and cannot actually tell us about health and disease. He explains why some genetic findings can be genuinely life-changing while many others offer information that is far more probabilistic than deterministic, and why directly measuring the phenotype is often more valuable than inferring risk from DNA alone. Peter examines where genetics can provide meaningful insight across the major disease categories and where its predictive power is far more limited than many people assume. He also discusses how to think critically about different types of genetic tests, how to interpret results in the proper context, and how to avoid the common trap of accumulating more genetic information without gaining greater clarity or actionable insight.

We discuss:

• Genetic testing: understanding what it can reveal, where it falls short, and how to think about its clinical value [1:45];
• The Human Genome Project: why decoding DNA did not immediately unlock the mysteries of disease [4:15];
• The limitations of genetic testing: probabilistic risk, interpretive uncertainty, and the importance of phenotype [9:30];
• Questions to ask when considering genetic testing [15:45];
• Genetic testing in cardiovascular and metabolic disease: when genotype adds value beyond phenotype [17:00];
• Genetic testing for inherited cardiac conditions: identifying hidden risk beyond routine screening [21:45];
• Genetic testing for cancer risk: inherited syndromes, clinical utility, and the limits of consumer testing [24:00];
• Genetic testing for neurodegenerative disease: risk prediction, planning, and the challenge of limited actionability [28:45];
• Functional medicine genetic testing: the gap between biological plausibility and clinical evidence, and the supplement protocols that aren't supported by evidence [32:45];
• Pharmacogenetics: using genetic testing to guide medication selection and safety [38:45];
• A framework for evaluating genetic tests according to effect size and clinical actionability [41:45];
• The major types of genetic tests, and how each should be matched to the clinical question being asked [43:30];
• Interpreting genetic test results: choosing the right testing laboratory and understanding what the findings actually mean [49:45];
• Framework summary: why genetic testing is most valuable when it is guided by a clear question, matched with the appropriate test, and capable of meaningfully influencing decisions [56:45]; and
• More.

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In this episode, Peter takes a deep dive into colorectal cancer (CRC) screening, explaining why it is one of the most preventable cancers and why getting screening right can have life-saving implications. He walks through how colorectal cancer develops and why it is uniquely well-suited to early detection and prevention, with a particular emphasis on the dual role of colonoscopy as both a diagnostic and therapeutic tool. Peter also examines the concerning rise in early-onset CRC among younger adults, highlighting why awareness and timely screening matter more than ever. The episode provides a practical guide to preparing for and evaluating the quality of a colonoscopy, including how to think about appropriate screening intervals and the real risks and tradeoffs involved. Finally, Peter explores the expanding landscape of non-invasive screening options, offering clear insight into what these alternatives can and cannot do so listeners can make informed decisions about their care at any age.

We discuss:

• CRC statistics and goals for this episode [1:00];
• Colorectal cancer development: polyp progression, risk types, and the window for prevention [4:00];
• Why colorectal cancer is uniquely screenable: direct visualization and the dual role of colonoscopy [6:30];
• Colonoscopy effectiveness: prevention through polyp removal and interpreting the NordICC trial data [8:15];
• Rising colorectal cancer in younger adults: trends, possible causes, and the case for earlier screening [12:15];
• Colonoscopy preparation: why bowel prep matters and how newer options improve the experience [16:45];
• Colonoscopy quality, polyp miss rates, and personalized screening intervals [20:00];
• Colonoscopy risks versus colorectal cancer risk: understanding the true risk-benefit tradeoff [29:30];
• Non-invasive screening options for CRC: benefits, limitations, and their role alongside colonoscopy [37:00];
• Colorectal cancer prevention principles: why screening matters and the role of colonoscopy [39:30]; and
• More.

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