The Longevity Nutrient: The Unexpected Fat That Holds The Key to Healthy Agingv

by Stephanie Venn-Watson

Unlock the secret to longevity with Dr. Stephanie Venn-Watson’s “groundbreaking, once-in-a-century discovery” (Mark Hyman, MD, New York Times bestselling author) of the molecule —an essential fat found in whole milk, cheese, and fatty fish—that can improve your health and increase your lifespan.

The hunt for the holy grail of healthy aging has been ongoing for hundreds of years, and Dr. Stephanie Venn-Watson may be its most unlikely champion. As a veterinary epidemiologist, she was recruited by the US Navy to lead a clinical research program to continually improve the health of Navy dolphins. Using advanced biotechnology to study the healthiest aging dolphins, she discovered a saturated fat which has the potential to expand both the health-span and lifespan in long-lived mammals.

In The Longevity Nutrient, Dr. Venn-Watson unveils the science behind the first essential fatty acid to be discovered in nearly a hundred years. This revolutionary discovery identifies the crucial ingredient for combating chronic aging-associated diseases. This book unfolds like a detective story, bringing you along through the science and discovery of this extraordinary nutrient. The implications of adding this nutrient back into the American diet could not be more significant. Mounting scientific evidence supports that

- Reduce the risk of and reverse fatty liver disease.
- Reduce the risk of and reverse type 2 diabetes and heart disease.
- Meaningfully slow the effects of aging to improve overall well-being.

Perhaps the most surprising discovery? In the end, it may just be the saturated fat that saves us all.

In this “life-changing” (Thomas DeLauer, author of Intermittent Fasting Made Easy) book, Dr. Venn-Watson tells the extraordinary story of this discovery and examines the paradigm shifting implications for human health and aging. She presents the easy, practical steps for you to responsibly bring this essential fat into your life to improve your long-term health and wellness.

Genres: Health, Nonfiction

Audible Audio

Published March 25, 2025

Reviews

[Donna · Rating 1 out of 5]

Bottom line: C15.0 is a miracle but you won’t be able to get it’s benefits unless you take it in supplemental form.

It just so happens the author has patented and sells c15.0! A year supply costs $459.95.

You’re welcome

[Molly · Rating 5 out of 5]

Dr. Venn-Watson provides such clear and compelling science about this rarely heeded nutrient. I started supplementing with C15:0 a couple of years ago and can’t say enough good things about how it made me feel. Now after reading this book, I’m even more convinced. I don’t have a background in science, but I am interested in improving my health, and this book is easy to read and understand, and chock full of evidence that make me want to supplement with C15:0 forever.

[Jan Peregrine · Rating 2 out of 5]

This nonfiction book, The Longevity Nutrient: The Unexpected Fat that May Hold the Key to Healthy Aging certainly got my attention and I excitedly started reading the book by Stephanie Venn-Watson, a dolphin doctor with the Navy. She explains how she discovered this fatty acid from studying the difference between California and South Florida dolphins. While the former were sickening over the decades similarly to humans, the latter were much healthier. Her book makes you think this nutrient has been so much in decline in our diets that it's the main reason for most of our health problems.

Sadly, though, the book's not much more than a get-rich scam. A very pricey, pure form of the odd-chain fatty acid, as Venn- Watson recommends, is sold on Amazon and it's manufactured where she lives and works in San Diego.

I first became suspicious when she explained that we used to get this essential nutrient from whole milk and cheeses, but then saturated fat became vilified and our health has gotten worse since then.

Those Florida dolphins seemed to have eaten different kinds of fish that had lots of this nutrient, but she didn't think to study over the last two decades if those fish were feeding on different algae that produced this special nutrient. It really irks me that a doctor simply assumed we would just take her word that an animal instead of a plant growing out of Earth could manufacture a nutrient.

Maybe she doesn't recommend we drink whole dairy milk and cheeses because of their other saturated fat chains, but she advises that our gut bacteria will never be able to produce enough because, I guess, we can't supplement inulin as well as her very pricey, pure supplement of the nutrient?

Bullshit!

Yes, our gut bacteria may need a lot of rebalancing and it'll take time for this nutrient to be in healthy amounts, but so will it take time for a pure form of it to not get eaten up by bad bacteria.

What is missing from this book is honesty, common sense, and actual concern for our health.

I've started taking chicory root supplements, but inulin is also in Jerusalem Artichokes as well as other plants in lesser amounts. Microalgae is a great source, but probably less available than inulin.

This nutrient may activate our endocannabinnoid system better than cannabis. I hope so!

[Benjamin Finley · Rating 4 out of 5]

This is a pretty good book with some interesting and useful health facts and studies. The background on longevity science was well laid out too. My only complaint about the author is that she should’ve disclosed she has a financial interest in the nutrient C15. It’s fine to believe in your supplements and have a financial interest in selling them - just disclose that very important fact to your readers so they can judge the authors objectivity with the proper context.

[Eileen · Rating 4 out of 5]

The book was well written and intriguing--I have not looked up any of her references however if I had known (before I bought the book) that she and her husband are the proprietary owners of the only company from which you can buy C15:0, I probably wouldn't have bought the book! I have a healthy dose of skepticism when people are hawking their own product--sort of like Dr. Gundry. My initial reaction to it costing approx. $500/year was shock. But then again, if you don['t have medical insurance, many drugs (often proprietary) can cost $500/month or more, let alone a year. The real question is does C15:0 (sold as Fatty 15) actually PREVENT disease, REVERSE cancers in humans and does it increase your level of C15:0? They will also measure your levels of C15:0 for $185. Seems to me this is more of a money-making endeavor than a health promotion endeavor. Bur we live in a capitalist society so I guess if you discover something, you want to make money from it.

I need more medical endorsement besides her husband (a physician).

[C.A. Gray · Rating 3 out of 5]

I've seen the "Fatty 15" advertisements all over, and I've had a few patients swear by them--so out of curiosity, I picked up this book.

The plusses: I'd never heard of C15:0 before, and it does have some compelling research behind it in terms of longevity, mitochondrial support, and reversing metabolic markers. There's even a section in here on ferroptosis which is pretty cutting edge, as far as I'm concerned... and how C15:0 can help stabilize cell membranes and reverse the process. Very clinically interesting.

The minuses: first of all, the author's style really set my teeth on edge. She's like an overly enthusiastic kindergarten teacher ("yay science!" and the like. It hits me as very condescending, even though I know that wasn't the intention. But my biggest complaint is that she goes into great detail about how you can't get C15:0 from food (it's found in food, but there are drawbacks to those foods, too). She didn't convince me of this, both because her analysis of that data is superficial, and because my worldview holds that any food God made, in the way He made it, cannot be inherently unhealthy. Also, the only alternative to consuming C15:0 in whole foods is to take it in supplement form--and she happens to own the company that makes the only commercially available version. Hmm...

[Allie Carlisle · Rating 5 out of 5]

I am not a science person in the slightest, but I found this book engaging and easy to read throughout.

Dr. Stephanie Venn-Watson is a gifted writer, and she so thoughtfully argued for the efficacy of C15:0 as an essential fatty acid.

So many books in the natural health world seem to be 75% trying to impress their scientific colleagues, 25% trying to help people. I appreciate how she took deep, mind bending science and humbly presented it in laymen’s terms in an effort to present this truly groundbreaking research to the public.

I can see where others are coming from in the reviews, as she does own the only company that sells pure encapsulated C15:0 at a hefty price and the book basically ends by telling you that taking pure C15:0 is the only way to overcome the deficiency. But her company is meeting a real need and charging what they have to charge as the only one on the market, so I don’t have a problem with it.

[Roy Turner · Rating 1 out of 5]

The Longevity Nutrient provides an overview of C15:0 as a key longevity nutrient, but the author’s central premise—that odd-numbered carbon chains are inherently anti-inflammatory and even-numbered chains inherently inflammatory—is fundamentally flawed.

While the research on C15:0 is interesting and insightful, the interpretative leaps undermine the book’s credibility. Moreover, the author markets an expensive C15 supplement throughout the text—despite C15:0 being readily available through common foods—making the book feel more like a vehicle for product sales than a neutral appraisal of the science.

I do not recommend this for anyone seeking medical or psychological guidance. The inaccuracies and commercial bias could lead to misguided interventions.

*Thanks to Microsoft Copilot for helping us craft this review*

[Michael Helm · Rating 4 out of 5]

Makes the case for C15:0 being important in longevity and general health.
This essential fatty acid seems to be needed in relatively low dosages and is claimed to be more important than fish oils and a better longevity drug therapy than for example metformin or rapamycin.

Is it true? There is so much reversion to the mean on studies like this that skepticism is warranted. The claim is that you can only get sufficient blood levels, low as they may be, from supplements and that foods high in this fatty acid also have counter compounds.

I would consider taking the test and seeing what it shows.

I didn’t like the author’s attempts at informality - maybe she was trying to avoid writing a journal article - but not letting that get in the way.

[Catalina Bilandzija · Rating 3 out of 5]

3.5 stars! Woooo second book by UCSD Alum that I have read! Super cool book and really interesting topic surrounding nutrition and health (plus dolphins!) More reason to love cheese. Interested to see more research on C15 and its future in longevity and health! A light non fiction read, if you are interested in topics of health I recommend

[Suz BB · Rating 4 out of 5]

Stephanie Venn-Watson discovered C15:0 as a healthy fat that slows biological aging and helps prevent/treat diseases of aging while studying navy dolphins. There is a caveat of food sources of C15, namely that these soures also contain C16, which conteracts some of the positive. Her solution: C15 supplements.

[Drooglord · Rating 4 out of 5]

9 hour infomercial

[Ali · Rating 5 out of 5]

The Longevity Nutrient presents relatable science and Dr. Venn-Watson's groundbreaking discovery while studying Navy dolphins, revealing how a specific nutrient impacts long-term health. She explains how this nutrient can improve cellular health, reshaping my understanding of nutrition and aging for both myself and my family. Despite lacking a medical background, I found the material easy to understand and realized that neglecting my cellular health would lead to faster, unhealthy aging. This awareness has led me to make mindful changes to my diet, such as switching from skim milk to whole-fat dairy. I highly recommend The Longevity Nutrient to anyone interested in health, wellness, and the science of aging. Dr. Venn-Watson’s expertise and dedication to improving global health make this a must-read for anyone seeking a healthier, longer life.