Dr. Rich Miller: “There Are No Biomarkers of Aging”

ReProgram Episode 17: *There Are No Biomarkers of Aging* 🧠 *Episode Overview* What if “biological age” as a single number is the wrong way to think about aging? In this episode of The ReProgram, Dr. George Murphy sits down with Dr. Rich Miller at the Gordon Research Conference Systems Aging Meeting in Maine. Dr. Miller is a Professor of Pathology at the University of Michigan and one of the leaders of the Interventions Testing Program, the gold standard for testing longevity interventions in genetically diverse mice. This conversation challenges some of the biggest assumptions in longevity science: biomarkers of aging, cellular senescence, the search for one cause of aging, and the idea that mouse lifespan results automatically translate into human recommendations. The central message: Aging is not one pathway, one biomarker, or one number. The real question is not simply what causes aging. The real question is what can postpone many forms of age-related decline at the same time. 🔑 *Keywords* Rich Miller, Richard Miller, Interventions Testing Program, ITP, aging biology, longevity science, geroscience, biological age, biomarkers of aging, aging-rate indicators, anti-aging drugs, geroprotectors, rapamycin, acarbose, ergothioneine, caloric restriction, sex differences in aging, interleukin-11, IL-11, genetically diverse mice, cancer and aging, Alzheimer’s and aging, healthspan, lifespan extension, longevity interventions, ReProgram Podcast, Dr. George Murphy 🧠 *Takeaways* • Aging should not be reduced to one cause, one pathway, one biomarker, or one biological age number. • Rich Miller argues that the key question is not what causes aging, but what postpones many forms of age-related damage at once. • Lifespan is useful because it is definitive, but a true anti-aging drug should also delay multiple forms of functional decline. • Most proposed longevity interventions fail when tested rigorously. • Biomarkers of aging and aging-rate indicators are not the same thing. • A biomarker may change with age. An aging-rate indicator should tell us whether aging is moving faster or slower. • “Biological age” as a single number may hide important differences across tissues, systems, and disease risks. • Ergothioneine is intriguing in slow-aging mice, but it is not yet clear whether it is causal or simply a marker of a broader metabolic state. • Sex differences matter. Some interventions work in male mice but not female mice. • Genetically diverse mice are essential for making aging research more relevant to real populations. • Rapamycin and acarbose are exciting in mice, but they are not proven human longevity drugs. • No drug has yet been proven to extend human lifespan by slowing aging itself. 🎙️ *The ReProgram Perspective* The ReProgram lens is simple: Mechanism over marketing. Outcomes over biomarkers. Trade-offs over hype. This episode is a reminder that longevity science needs both ambition and restraint. A compound that changes a biomarker has not necessarily slowed aging. A drug that extends lifespan in mice is not automatically safe or effective for humans. And a single “biological age” number may not capture the complexity of how real people age. Rich Miller’s message is not that aging biology is impossible. It is that the field has to be precise about what the data actually prove. The future of longevity science depends on rigorous testing, better endpoints, genetic diversity, sex-specific biology, and a clear distinction between promising mechanisms and proven outcomes. *Chapters* 00:00 Are There Really Biomarkers of Aging? 02:09 Dr. Rich Miller’s Origin Story 03:24 How His Views on Aging Changed 04:21 How Rich Miller Defines Aging and Its Complexities 05:48 The Interventions Testing Program (ITP) 07:31 What Is a True Anti-Aging Drug? 08:37 Longevity Signatures and Metabolites 10:33 The Role of Ergothionine in Aging 13:17 Biomarkers vs Aging-Rate Indicators 16:26 Sex Differences in Aging Research 19:11 The Importance of Genetically Diverse Models 22:09 Advocating for Aging Research 23:45 Aging Research and Cancer 25:19 Disease Silos in Science 27:11 Rich Miller’s Own Longevity Habits 29:51 The Risk of Rapamycin Self-Experimentation *Notes* The Interventions Testing Program (ITP): https://www.nia.nih.gov/research/dab/interventions-testing-program-itp Dr. Rich Miller Lab: https://www.richmillerlab.com/