Omega-3s (EPA and DHA) in oily fish and supplements support heart, triglyceride, brain, and eye health. Prefer seafood first; use supplements or prescription omega-3s under medical guidance.
Distilled (purified) fish oil is refined to remove contaminants and concentrate EPA/DHA. It can lower triglycerides and has specific cardiovascular uses; benefits for mood or stress are mixed. Choose products with third-party testing and consult your clinician for dosing.
Deep-sea fishes live below the sunlit ocean layer and show unique adaptations. Fish oils rich in EPA and DHA largely come from small oily fish (and historically shark liver), and evidence for health benefits depends on dose, formulation, and patient group.
Fish oil supplements provide EPA and DHA for heart and brain health; choose third-party-tested products and consult a clinician for high-dose or medical use.