The Proof with Simon Hill

Is this supplement legitimate? Science of Fatty15 and C15:0 | Bill Harris, PhD

Mar 3, 2025

In this engaging discussion, Dr. Bill Harris, a leading expert in fatty acid research, dives deep into the controversial supplement C:15. He evaluates claims of it being the first essential fat in 90 years and its purported health benefits, including comparisons to omega-3s. Dr. Harris challenges the marketing hype, scrutinizing the evidence from population studies and clinical trials on cholesterol and inflammation. He also explores the implications of patenting natural compounds, urging a more critical approach to supplement claims.

56:11

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Bill Harris

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Quick takeaways

Pentadecanoic acid, or C:15, lacks sufficient evidence to support its claims as an essential nutrient despite marketing assertions by Fatty15.

The podcast emphasizes the need for rigorous scientific validation of health claims surrounding C:15 to prevent misleading consumers about its benefits.

Deep dives

Pentadecanoic Acid and Emerging Health Claims

Pentadecanoic acid, also known as C15, has gained attention for its potential health benefits, particularly regarding liver function, metabolism, and longevity. This saturated fatty acid, researched by Dr. Stephanie van Watson and her team, is marketed by the company Fatty15 with bold claims of being the next essential fat akin to omega-3 fatty acids. However, such claims necessitate rigorous scientific validation, as the current body of research lacks comprehensive studies connecting C15 to definitive health improvements. While preliminary research suggests some associations with metabolic health outcomes, the absence of conclusive evidence raises concerns about the validity of these marketing assertions.

Intro

3min

Unpacking C:15 and Dietary Fats

8min

Understanding Nutritional Complexity: Beyond Single Nutrients

2min

Exploring C15 and C16: Essential or Not?

16min

Navigating Industry-Funded Research and Consumer Misunderstanding

2min

Cholesterol Insights: Scrutinizing the Tango Trial Claims

3min

Analyzing Complex Study Data and Its Implications

2min

C15 vs Omega-3: A Critical Examination

20min

You may have heard claims that C15:0 (pentadecanoic acid) is the first essential fat discovered in 90 years, a powerful longevity booster, and a game-changer for metabolic health. But how much of this is backed by solid science?

In this episode, I sit down with Dr. Bill Harris, a leading expert in fatty acid research, to critically evaluate the evidence behind C15:0. We break down the population studies linking it to health benefits, the key clinical trials testing its effects, and whether the marketing around Fatty15 is ahead of the actual data.

In this episode, we cover:

What exactly is C15:0, and how does it compare to other fats?
The claim that C15:0 is an essential nutrient—does it meet the criteria?
The current evidence on C15:0 and its impact on cholesterol, glucose, and inflammation
Does C15:0 supplementation mimic omega-3s, metformin, or rapamycin?
The broader issue of patenting a naturally occurring compound

For more details and supporting studies, visit the full show notes.

Introduction to Pentadecanoic Acid (C15:0) (00:00)
Evaluating the Claims of C15:0 (02:05
Comparing C15:0 with Other Fatty Acids (03:12)
Health Implications of Dairy Fats and the Essentiality of C15:0 (05:02)
Scientific Evidence and Studies on C15:0 (13:12)
Interpreting Clinical Trial Results, Cholesterol, and the Tango Trial (27:59)
Cholesterol and the Tango Trial (28:28)
Comparing C15:0 to Omega 3s (32:02)
Future Research Directions for C15:0 (37:46)
Longevity Claims and Patents (42:30)
Final Thoughts and Conclusion (49:44)

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Simon Hill, MSc, BSc (Hons)

• Creator of theproof.com

• Host of The Proof with Simon Hill

• Author of The Proof is in the Plants

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