Altered States

The Life-Extension Episode — Dr. Matt Kaeberlein on The Dog Aging Project, Rapamycin, Metformin, Spermidine, NAD+ Precursors, Urolithin A, Acarbose, and Much More (#610)

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“I constantly tell the people in my lab and other scientists, ‘You’ve got to do the experiment.’ You cannot go into it thinking that you know the answer and not do the experiment because your dogmatic belief says, ‘This is how it’s going to work.’ You’ve got to do the experiment.”

— Dr. Matt Kaeberlein

Dr. Matt Kaeberlein (@mkaeberlein) is a professor of Laboratory Medicine and Pathology at the University of Washington School of Medicine, with adjunct appointments in Genome Sciences and Oral Health Sciences. Dr. Kaeberlein’s research interests are focused on understanding biological mechanisms of aging in order to facilitate translational interventions that promote healthspan and improve quality of life for people and companion animals.

Dr. Kaeberlein is the founding director of the University of Washington Healthy Aging and Longevity Research Institute, the director of the NIH Nathan Shock Center of Excellence in the Basic Biology of Aging at the University of Washington, director of the Biological Mechanisms of Healthy Aging Training Program, and founder and co-director of the Dog Aging Project.

Please enjoy!

Listen to the episode on Apple Podcasts, Spotify, Overcast, Podcast Addict, Pocket Casts, Castbox, Google Podcasts, Stitcher, Amazon Musicor on your favorite podcast platform.

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#610: The Life-Extension Episode — Dr. Matt Kaeberlein on The Dog Aging Project, Rapamycin, Metformin, Spermidine, NAD+ Precursors, Urolithin A, Acarbose, and Much More

This episode is brought to you by LMNTWhat is LMNT? It’s a delicious, sugar-free electrolyte drink mix. I’ve stocked up on boxes and boxes of this and usually use it 1–2 times per day. LMNT is formulated to help anyone with their electrolyte needs and perfectly suited to folks following a keto, low-carb, or Paleo diet. If you are on a low-carb diet or fasting, electrolytes play a key role in relieving hunger, cramps, headaches, tiredness, and dizziness.

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Want to hear another podcast episode that explores the possibilities of rapamycin? Have a listen to the conversation I had with Peter Attia, David M. Sabatini, and Navdeep S. Chandel at the source of this miraculous compound: Easter Island. Here, we discuss how one of the most important discoveries of medical science was almost lost, why metabolism (along with longevity) research is key to treating a long list of diseases, intermittent dosing of rapamycin, parenting advice from scientists on confidence and conflict, the necessary failures of good science, good fonts versus bad fonts, “non-potato” relationships, and much more.

#193: My Life Extension Pilgrimage to Easter Island

What was your favorite quote or lesson from this episode? Please let me know in the comments.



  • Connect with Dr. Matt Kaeberlein:

Website | Twitter | LinkedIn


Note from the editor: Timestamps will be added shortly.

  • What is aging biology?
  • How Matt pivoted from mathematics to biology.
  • What is the Dog Aging Project?
  • Understanding healthspan through Matt’s frozen shoulder ordeal.
  • Rapamycin vs. sterile inflammation.
  • Current thoughts about how the immune system changes as we age.
  • Anti-aging uses for rapamycin (and potential risks/side effects).
  • Rapamycin and the Dog Aging Project.
  • Rapamycin vs. neurodegeneration.
  • What studies tell us about rapamycin’s potential to increase lifespan.
  • Rapamycin alternatives considered for the Dog Aging Project.
  • Urolithin A and spermidine.
  • 17 alpha estradiol.
  • Deprenyl.
  • NAD precursors.
  • What is Matt doing to increase his own lifespan/healthspan?
  • Is time-restricted feeding beneficial for dogs?
  • Currently, how well (or poorly) funded is longevity research?
  • Where additional funding in this field would be best leveraged.
  • Cutting through the hype and snake oil.
  • Metformin.
  • NAD infusion vs. natural NAD replenishment.
  • Sirtuins.
  • Resveratrol.
  • Is there a fix to liability in defensive medicine?
  • Finding better motivations for scientific pursuit.
  • Longevity scientists worth checking out.
  • Getting involved with the Dog Aging Project and parting thoughts.


“If you look at almost all of the major killers in developed countries, they all share a single greatest risk factor, and it’s how old you are. And that’s because of the underlying biology that creates a change in our physiology that is permissive for all of those diseases to happen.”
— Dr. Matt Kaeberlein

“We’ve got these misbehaving cells. They’re good-for-nothing, do-nothing cells that just kind of hang out and convince the other cells to do bad stuff. So if we could get rid of them, that’d be a good thing. It turns out it’s probably not that easy.”
— Dr. Matt Kaeberlein

“Being a dog guy and wanting my dog to live longer, when that light bulb went off in my head, I was like, ‘This goddamn has to happen.’”
— Dr. Matt Kaeberlein

“I constantly tell the people in my lab and other scientists, ‘You’ve got to do the experiment.’ You cannot go into it thinking that you know the answer and not do the experiment because your dogmatic belief says, ‘This is how it’s going to work.’ You’ve got to do the experiment.”
— Dr. Matt Kaeberlein

“People pay no attention to the psychological consequences that go along with trying to practice caloric restriction or trying to practice time-restricted feeding or intermittent fasting. I’m not saying they’re bad for everybody, but I know a lot of people who’ve dabbled with these things, and I would say some of the psychological effects aren’t great.”
— Dr. Matt Kaeberlein

“If you really could modulate the biology of aging, it will improve age-related immune function.”
— Dr. Matt Kaeberlein

“[Many] physicians . . . are very resistant to the idea of doing anything for somebody who’s not sick to keep them well. And we have to change that.”
— Dr. Matt Kaeberlein


The Tim Ferriss Show is one of the most popular podcasts in the world with more than 800 million downloads. It has been selected for “Best of Apple Podcasts” three times, it is often the #1 interview podcast across all of Apple Podcasts, and it’s been ranked #1 out of 400,000+ podcasts on many occasions. To listen to any of the past episodes for free, check out this page.

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