Introduction

Subscribe to our channel: https://www.youtube.com/@optispan Matt recently exchanged a lively correspondence about biological age with Harold Katcher, cofounder of a stealth biotechnology company and inventor of E5. E5 is a compound consisting of the purified exosome fraction of blood from young piglets—in other words, young pig blood. Harold recently co-published a paper suggesting that injecting this young pig blood into rats made rats younger on several biological aging measures, including inflammatory markers and epigenetic aging signatures. Indeed, Harold has injected E5 into his own right hand and presented differences in the appearance of his right and left hands on social media. Putting pig blood into other animals (and into ourselves!) to reverse biological age might seem like a crazy thing to do. But this idea actually stems from a methodology with a decades-long history called heterochronic parabiosis, an area of research that explores the effects of joining the circulatory systems of different-aged organisms. In this experimental technique, researchers surgically connect two animals, typically mice, of disparate ages so that they share a common bloodstream. This union leads the older and younger individuals to exchange not just blood cells but also signaling molecules, growth factors, and other circulating factors. Remarkably, when an older animal is paired with a younger counterpart, it often experiences improvements in various aspects of health and tissue function, while the younger partner may exhibit corresponding signs of accelerated aging. The mechanisms underlying these effects are complex, multifaceted, and very much still under investigation. In this episode, Matt takes a magnifying glass to E5: what we know about the compound, how it affects lifespan, and how its impact on lifespan stacks up with that of other longevity inventions such as caloric restriction and rapamycin. He discusses whether Harold's recent paper truly proves a reversal of biological age and where his findings fit into the larger body of literature in the field. He also gives us a window into the methodology of heterochronic parabiosis, what the primary data about life expectancy gains through this intervention show, and whether heterochronic parabiosis-inspired interventions such as E5 are realistic approaches to human lifespan extension. Producers: Tara Mei, Nicholas Arapis Video Editor: Jacob Keliikoa DISCLAIMER: The information provided on the Optispan YouTube channel is intended solely for general educational purposes and is not meant to be, nor should it be construed as, personalized medical advice. No doctor-patient relationship is established by your use of this channel. The information and materials presented are for informational purposes only and are not a substitute for professional medical advice, diagnosis, or treatment. We strongly advise that you consult with a licensed healthcare professional for all matters concerning your health, especially before undertaking any changes based on content provided by this channel. The hosts and guests on this channel are not liable for any direct, indirect, or other damages or adverse effects that may arise from the application of the information discussed. Medical knowledge is constantly evolving; therefore, the information provided should be verified against current medical standards and practices. More places to find us: Twitter: https://twitter.com/optispanpodcast Twitter: https://twitter.com/optispan Twitter: https://twitter.com/mkaeberlein Linkedin: https://www.linkedin.com/company/optispan https://www.optispan.life/