In this fascinating conversation, Dr. Morgan Levine — a leading ageing researcher and assistant professor at Yale, now at Altos Labs — discusses how the epigenome reveals insights into biological ageing and how we might one day slow or reverse the ageing process. She introduces the concept of epigenetic ageing clocks, particularly PhenoAge and GrimAge, and explains how these tools go beyond chronological age to quantify cellular and molecular ageing.

Key Points:

This episode explores how epigenetic clocks like PhenoAge offer a more accurate way to measure biological ageing than relying on chronological age alone. Dr. Morgan Levine explains that much of what accelerates ageing is linked to lifestyle and environmental factors, making it potentially reversible. She also discusses the exciting promise of partial cellular reprogramming — an emerging technique that could one day slow or even reverse ageing at the cellular level.

• What Is Biological Ageing?: Dr. Levine explains how biological ageing reflects the wear and tear at the cellular and molecular level — not just the number of years lived.
• PhenoAge & Epigenetic Clocks: Second-generation clocks like PhenoAge and GrimAge better predict mortality and disease risk than first-generation clocks or traditional lab tests.
• Why People Age at Different Rates: Lifestyle factors such as smoking, diet, and exercise have more influence on epigenetic ageing than genetics, which accounts for only ~10–20%.
• Inflammation’s Role in Ageing: Chronic inflammation appears to be a key driver of epigenetic age acceleration, as seen in studies of cancer patients and COVID-19.
• Partial Cellular Reprogramming: Techniques using Yamanaka factors can reverse a cell’s epigenetic age without erasing its identity — offering a possible rejuvenation route.
• Ageotypes & Organ-Specific Clocks: People may be "metabolic agers" or "immune agers"; future clocks may track how different organs age at different rates.
• Cautions with Consumer Tests: Many available tests are unreliable due to noise; only some (like those based on PhenoAge with error correction) offer meaningful results.
• Ageing as a Program, Not Just Damage: Emerging evidence suggests ageing may be a continuation of developmental programs gone awry, not just the result of random damage.