How we know that aging is a biological function, and why it matters

This new video introduces my work in the context of a hundred years of evolutionary theory and the breakthrough rejuvenation science in the present.


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12 thoughts on “How we know that aging is a biological function, and why it matters”

  1. Fisetin is known to have low bioavailability. It’s suggested to take it with some fat, such as fish oil to improve bioavailability. However, to my knowledge this would break your fasting. Josh, can you please share how you take Fisetin during your fasting routine?

    Reply
    • I know you were asking Josh this question, but I thought I’d put in my two bits’ worth.

      Valter Longo’s “fasting-mimicking” diet provides many of the benefits of true fasting without the harsh exit from and re-entry to normal feeding. As it is relatively permissive of fats/oils within the caloric limits of the dietary framework, it is ready-made for optimizing fisetin absorption.

      I don’t mean to suggest that you switch from true fasting to the fasting-mimicking diet, but this does suggest that taking a small amount of fat/oil with some fisetin during a true fast would have relatively little impact on the beneficial effects of short-term starvation.

      Reply
  2. I’ve been expecting to see some mention by Josh concerning another recent paper out of China:
    https://www.cell.com/cell/abstract/S0092-8674(25)00571-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867425005719%3Fshowall%3Dtrue
    The title is “Senescence-resistant human mesenchymal progenitor cells counter aging in primates”. I think that the paper was freely-available for a time, but is now behind a paywall.

    The paper describes genetically-modifying human mesenchymal stem cells to make them resistant to senescence, and then injecting them into aged macaques, which then experience rejuvenation of multiple tissues. The authors attribute the results partly to exosomes produced by the stem cells. Some additional results were described where the exosomes alone were observed to produce rejuvenation in mice.

    A review paper summarizing the results is freely-available at:
    https://cellregeneration.springeropen.com/articles/10.1186/s13619-025-00248-8

    Apparently it is well-known that mesenchymal stem cell are remarkably non-immunogenic, allowing the to be used across species:

    https://pmc.ncbi.nlm.nih.gov/articles/PMC1215510/#:~:text=However%20the%20normal%20process%20of,humans%20and%20in%20animal%20models.

    Reply
    • I read the paper when it came out. It’s good work, but they take the position that aging is to be resolved at the cell level, and my belief has been that aging is not cell-autonomous but is centrally coordinated. I’ve chosen not to write a detailed response.

      Reply

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