Fatty15: The Little Fat That Could… Or Just Another Marketing Muffin Top?
One of the best parts of this journey is having mentors who push me to keep learning and questioning. @Elizabeth Yurth has been that kind of mentor for me. She’s not only a brilliant mind in cellular medicine, she’s also someone who constantly reminds me to dig deeper, challenge assumptions, and ask better questions. It was actually Dr. Yurth who got me to revisit the research around Fatty15. Her guidance along with the incredible work she’s doing through the Boulder Longevity Institute and her Human Optimization Academy has been a game-changer for me and so many others. Having people like her in my corner makes me a better student, a better teacher, and hopefully of better service to all of you. With that in mind, I wanted to share some thoughts on Fatty15, the hype, the skepticism, and what we can really learn from it when we zoom out and ask deeper questions. Fatty 15 has become one of the most talked-about molecules in the wellness and longevity space, not because it is new to science, but because of the way it has been packaged and sold. Marketed as the first “essential” odd-chain saturated fatty acid, Fatty 15 (the supplement form of C15:0) promises to stabilize membranes, reduce inflammation, and extend healthspan. For many, the narrative is seductive: here is a nutrient that has been hiding in plain sight, maligned by decades of anti-saturated-fat dogma, finally rebranded as a cornerstone of cellular resilience. But step back from the marketing and look at the science, and the picture becomes more complex. Lipidologists and metabolic researchers, including Dr. Dayan Goodenowe, argue that high levels of pentadecanoic acid in the blood are not causal but correlative. In other words, elevated C15:0 is a marker of robust lipid metabolism, not the reason for it. To use an analogy, it’s like noticing that healthy cities all have clean street signs and then deciding that shipping in more street signs will fix a crumbling city. The signs are a marker of order; they are not the thing that creates it. Supplementing with C15:0 without repairing upstream dysfunction may not move the needle and in some cases, may even make things worse.