That isn’t the case for omega-3 fatty acids (also called omega-3 fats and n-3 fats). Omega-3 fats are a key family of polyunsaturated fats. There are three main omega-3s: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) come mainly from fish, so they are sometimes called marine omega-3s.