What Are Omega-3 Fatty Acids? Omega-3s are nutrients you get from food (or supplements) that help build and maintain a healthy body. They're key to the structure of every cell wall you have. They're also an energy source and help keep your heart, lungs, blood vessels, and immune system working the way they should. In this episode we look in more depth what this is and how it can help your health and how to consume more of it.