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.

Two crucial ones — EPA and DHA — are primarily found in certain fish. ALA (alpha-linolenic acid), another omega-3 fatty acid, is found in plant sources such as nuts and seeds.

DHA levels are especially high in retina (eye), brain, and sperm cells.