EP 1399
1399. Eat These Foods + Spices for 8 Weeks To Get 3 Years Younger | Kara Fitzgerald
In this episode of The Human Upgrade, Host Dave Asprey sits down with Dr. Kara Fitzgerald, ND, IFMCP, a functional medicine clinician and epigenetic researcher whose peer-reviewed studies proved that a targeted diet and supplement protocol can reverse biological age on validated epigenetic clocks, to break down exactly how her randomized controlled trial produced over three years of biological age reversal in just eight weeks using food, supplements, and meditation, why polyphenol compounds called methylation adaptogens do the heaviest lifting in epigenetic rejuvenation and how they differ from methyl donors like TMG and folate, what Yamanaka factors actually are and why the Nobel Prize-winning discovery that can wind a 90-year-old skin cell back to its 20s represents the most radical anti-aging frontier in science today, how compounds already in use like AKG, sodium butyrate, and forskolin may act as Yamanaka mimetics without the risks of full cellular reprogramming, what the PRC2 polycomb repressive complex clock reveals about the deeper mechanisms driving programmatic aging, why high-oxalate superfoods may be silently damaging mitochondria even in people who never develop kidney stones, and why the dark matter of nutrition, the thousands of polyphenolic compounds we have barely begun to map, may matter more for long-term human performance than any macro ratio, carnivore protocol, or ketosis strategy currently in use.
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In this Episode of The Human Upgrade™...
Your biological age can drop by over three years in just eight weeks, and the tools to do it are already in your kitchen. This episode breaks down the cutting-edge science of methylation, polyphenols, Yamanaka mimetics, and epigenetic reprogramming that is rewriting what we know about anti-aging, longevity, and human performance.
Host Dave Asprey sits down with Dr. Kara Fitzgerald, ND, IFMCP, a leading voice in functional medicine and epigenetic aging research. Her award-winning clinical studies published in Aging (2021, 2023, and 2025) proved that targeted diet and lifestyle interventions can measurably reverse biological age on validated epigenetic clocks. She is the author of Younger You, an IFM faculty member and Certified Practitioner, and one of the most rigorously credentialed researchers working at the intersection of functional medicine, nutrition, and longevity science today.
Together, they go deep on Yamanaka factors, the Nobel Prize-winning discovery that can wind back a 90-year-old cell to its 20s, and the emerging class of compounds called Yamanaka mimetics, polyphenol-based supplements that may replicate some of those same cellular rejuvenation effects without the risks. They cover why polyphenols do the heavy lifting in biological age reversal, how AI is accelerating longevity research, and why the dark matter of nutrition may matter more than macros, carnivore protocols, or ketosis for long-term health. They also get into oxalates, mitochondria, fibroids, ovarian rejuvenation, and why the original Horvath clock may be more relevant than scientists thought.
This is essential listening for anyone serious about biohacking, longevity, supplements, functional medicine, anti-aging, brain optimization, human performance, and using smarter not harder strategies to take control of your biology.
You’ll Learn:
- How diet, supplements, and meditation reversed biological age by over three years in eight weeks in a randomized controlled trial
- What Yamanaka factors are and why scientists are calling partial cellular reprogramming the future of anti-aging
- Which polyphenols do the heaviest lifting for epigenetic rejuvenation, including EGCG, urolithin A, rosemary, marjoram, and yarrow
- Why the Horvath epigenetic clock may actually be touching on programmatic aging rather than just exposomic wear and tear
- How AI is unlocking patterns in longevity data that no human researcher could find alone
- The problem with high-oxalate superfoods and how to get polyphenol benefits without the inflammatory downside
- Why ovarian rejuvenation may be the highest-leverage Yamanaka application for women’s longevity and brain health
- How compounds like AKG, sodium butyrate, and forskolin may act as Yamanaka mimetics already available today
- What the PRC2 polycomb clock reveals about programmatic aging and why it matters more than second-generation clocks
- Why perimenopause does not have to be painful, and how functional medicine addresses it at the root
Keywords: Kara Fitzgerald, biological age reversal, epigenetics, DNA methylation, Yamanaka factors, polyphenols, EGCG, urolithin A, anti-aging, longevity, biohacking, functional medicine, supplements, mitochondria, epigenetic clock, cellular reprogramming, AKG, sodium butyrate, methylation, Steve Horvath, Vittoria Sebastiano, coleus, perimenopause, ovarian rejuvenation, pluripotent stem cells, PRC2, dark matter of nutrition, TRIM study, dihydroxyflavone, BDNF, Prenuvo, chemical cellular rejuvenation
Resources:
- Learn more about all of Dr. Fitzgerald’s work at: https://www.drkarafitzgerald.com/
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"We had lowered biological age by over three years in our study subjects in eight weeks' time with some food and supplements and meditation."
Kara Fitzgerald
00:00 – Trailer
Dr. Kara Fitzgerald reveals that study subjects lowered their biological age by over three years in just eight weeks using food, supplements, and meditation.
01:28 – Explaining Study
Dr. Fitzgerald walks through the origins of her research, tracing her entry into epigenetics through a functional medicine lens around 2013 and explaining how the randomized controlled trial came together.
03:45 – What Is The Diet
The protocol combined methyl donor-rich foods like eggs, liver, and beets with methylation adaptogens, primarily dense polyphenol compounds like EGCG, across seven to eleven cups of fruits, vegetables, herbs, and spices daily.
06:49 – Age Reversal
Biostatistician Josh Middeldorf confirmed that compared to the control group, study subjects reversed biological age by over three years on the Horvath multi-tissue clock in eight weeks.
08:17 – Polyphenols vs. Supplements
Dave and Dr. Fitzgerald debate whether food alone can deliver a therapeutic polyphenol dose, with Dave noting he takes 800mg of EGCG daily, far more than any realistic tea intake could provide.
09:27 – Food vs. Supplement Dosing
Dr. Fitzgerald argues that a sophisticated dietary pattern delivers a complexity of polyphenolic touchpoints that a single supplement cannot replicate, while acknowledging there is a place for high-concentration formulations layered on top.
12:41 – Oxalate & Polyphenol Trade-offs
Dave explains why he has shifted toward encapsulated polyphenol supplements, pointing to oxalate accumulation in connective tissue and mitochondria as a hidden cost of relying on high-oxalate superfoods like turmeric and buckwheat.
18:41 – Yamanaka Factors Explained
Dr. Fitzgerald breaks down how Yamanaka’s Nobel Prize-winning transcription factor cocktail can take a somatic cell all the way back to a pluripotent stem cell state, effectively shaving decades off a cell’s biological age.
28:59 – Chemical Cocktails
They discuss Sinclair’s chemical cellular rejuvenation work and identify compounds already in use, including AKG, sodium butyrate, and forskolin, that may act as Yamanaka mimetics by gently nudging cells toward a younger state.
32:15 – PRC2 Clocks & Programmatic Aging
Dr. Fitzgerald introduces the polycomb repressive complex 2 clock developed in Vittoria Sebastiano’s lab, explaining how it may measure programmatic aging rather than just the wear and tear of life experience.
40:28 – Seasonal Eating
Dave questions the “eat a rainbow” advice, pointing out that traditional diets were seasonally constrained, and both agree that personalized polyphenol targeting based on individual biology is where the science is heading.
43:40 – Carnivore Diet: Short vs. Long Term
Dr. Fitzgerald calls carnivore the world’s best elimination diet for short-term results, while Dave shares how months of meat and butter improved his body composition but quietly destroyed his sleep and gut integrity.
45:31 – Inuit Diet
Dave and Dr. Fitzgerald note that the Inuit’s seemingly all-animal diet was actually rich in omega-3s and polyphenols from berries and herbs, suggesting the French paradox and Inuit longevity both trace back to plants more than macros.
46:39 – Flavones & Brain-Crossing Compounds
Dave introduces dihydroxyflavone, a synthetic flavone small enough to cross the blood-brain barrier and directly activate the BDNF receptor, pointing to a class of compounds that act on neuroplasticity the way the body’s own molecules do.
48:50 – Why Only Men in the Study?
Dr. Fitzgerald explains that including pre, peri, and postmenopausal women in a small cohort would have introduced hormonal confounding variables that would have made the data impossible to interpret cleanly.
51:05 – Women, Perimenopause & the Protocol
Dr. Fitzgerald shares that women who followed the dietary protocol in clinical practice showed biological age reversal comparable to or exceeding the men in the original trial, and reports that perimenopausal symptoms improve significantly with methylation-supportive nutrition.
53:20 – Fibroids & Gaps in Women’s Research
Dr. Fitzgerald flags uterine fibroids as a massive blind spot in women’s health research, noting a recent publication linking them to increased cardiovascular disease risk and arguing that the field has dramatically underinvested in understanding their root causes.
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