episode #10

Dr. David Sinclair – Why We Age and Why We Don’t Have To



Harvard Medical School professor, genetics expert, and author Dr. David Sinclair joins the podcast to share his expertise on the subject of molecular genetics and the biology of aging. In this episode, Dr. Stephanie and Dr. David break down the impact that sirtuins and NAD+ have on our longevity. According to Dr. David, aging is twenty percent genetics and eighty percent lifestyle. Thus, the secret to anti-aging can be found in how we choose to live. Dr. Stephanie and Dr. David discuss the epigenetic clock, hormesis, and the benefits of resveratrol. Finally, Dr. David analyzes Horvath’s Clock and speaks to the importance of measuring age accurately.


  • 00:52 – Introducing today’s guest, David Sinclair
  • 06:28 – David’s origin story
  • 08:38 – Why we age
  • 11:17 – The genome and epigenome
  • 13:00 – The piano metaphor
  • 15:51 – Sirtuins explained
  • 21:59 – Other environmental stressors that sirtuins detect
  • 25:11 – Hormesis defined
  • 28:13 – How NAD+ and its precursors combat aging
  • 35:11 – Dr. Stephanie brings up a specific story from Dr. David’s book
  • 38:40 – Friedreich’s Ataxia
  • 39:27 – Benefits of resveratrol
  • 45:11 – Horvath’s Clock and measuring age accurately
  • 47:58 – The backup copy of the epigenome
  • 53:44 – Anti-aging technologies on the horizon
  • 55:07 – Other anti-aging best practices
  • 56:47 – Dr. Stephanie suggests a new sequel to the Avengers franchise
  • 57:48 – Dr. Stephanie thanks Dr. David for joining the show
  • 58:21 – Dr. David shares with the audience where they can find the cheat sheet in his book
  • 58:48 – Where listeners can follow Dr. David
  • 1:00:00 – Where listeners can follow Dr. Stephanie and subscribe to her newsletter


“I wrote the book because there’s a lot of really interesting technology and things people can do in their daily lives, I believe, to live significantly longer and healthier. But, I also wanted to start the conversation because I felt no one was really saying the kinds of things that I was saying.” (08:15)

“I think that the major driver of aging, put simply, is a loss of information.” (10:19)

“I think it’s worth clarifying that the sirtuins are protectors of our bodies, but they can also cause aging by being distracted too much.” (25:11)

“It’s all about being uncomfortable. Our bodies would much rather sit in a chair and eat popcorn. There’s a whole industry based on that.” (26:19)

“I like to joke that scientists like to fight because the stakes are so low.” (42:41)

“We can predict, very accurately, how old someone is biologically. And that’s not so much related to birthday candles. It’s more about how you’ve lived your life. Twenty percent of your age will be genetic and eighty percent will be how you’ve lived.” (46:59)

“What I don’t know is how to bring people back from the dead, but I think we’re getting close to being able to keep people alive in a healthy way for much longer.” (57:31)


Better! Website

Dr. Stephanie’s Website

Dr. Stephanie’s Twitter – @dr_stephanie

Dr. Stephanie’s Instagram – @dr.stephanie.estima

Dr. Stephanie on LinkedIn

Dr. David’s Book – Lifespan: Why We Age―and Why We Don’t Have To

Dr. David’s Website

Dr. David’s Instagram – @davidsinclairphd

Dr. David’s Twitter – @davidasinclair

Dr. David’s Facebook


In animal models, more NAD is better

At least when it is paired with exercise

The Mathematical Theory Of Aging

The Horvath Clock

Reversal Of Aging & Cellular Reprogramming

Resveratrol effects 1 

Resveratrol effects 2

NMN & lifespan in mice

David’s Newsletter

David’s book


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  • Dr. David Sinclair
  • Dr. Stephanie Estima

I’m Dr. Stephanie

Part geek, part magic, and all the way passionate about being a well-lived woman.

I want to throw my grandkids in the air in my 70’s. I want to be squatting even more weight than I am now, and putting my OWN luggage in the overhead bin. Sound like weird goals? For me these are just some of the little things that represent a life well-lived.

My health is MY job – I’ll be damned if I rely on luck, ‘good genes’ or a cocktail of drugs that over promise and under deliver.

The Betty Body is my first book-baby, and a collection of what I’ve learned after thousands of clinical hours, hundreds of conversations with the world’s top experts, and most importantly…

This book is an outline of what took ME from “rock-bottom health” at 38, to being my own version of a Betty in my perimenopausal mid 40’s. A woman who is physically strong, full of energy, enjoys mental clarity, great sex and a joyful family life. Is it all roses? Of course not. But I have the stamina and tools to deal with the push and pull of life so that it doesn’t turn into chronic stress.

I want this for you too. Let’s go Bettys!