Fatty 15/ New York Post Composite Not all heroes wear capes — some have flippers. Or, at least, such was the case when researchers began observing dolphins in the U.S. Navy’s Marine Mammal Program , and found that the healthiest, longest-living dolphins had higher levels of a key nutrient now known as C15:0. C15:0, or pentadecanoic acid, is an odd-chain saturated fatty acid that acts similarly to omega-3s, with proposed benefits for metabolic, cognitive, liver, immune and red blood cell health. Levels of C15:0 naturally decline with age, but it can be obtained through diet or supplementation. A 2023 study revealed that people with higher circulating C15:0 concentrations had a lower risk of aging-associated conditions.  That dolphin discovery — paired with further scientific research — helped inspire the widely sought-after Fatty15 capsules . Now, a decade later, this once-a-day supplement is backed by over 100 peer-reviewed studies and over 60 patents.…