EPA (Eicosapentaenoic Acid)

fatty-acid

A long-chain omega-3 fatty acid with 20 carbons.

Definition

A long-chain omega-3 fatty acid with 20 carbons. Primarily anti-inflammatory, supports heart health, and reduces triglycerides. Found in fatty fish. The body can produce small amounts from ALA but dietary intake is preferred.

What Is EPA (Eicosapentaenoic Acid)?

Eicosapentaenoic acid (EPA) is a long-chain omega-3 polyunsaturated fatty acid containing 20 carbon atoms and 5 double bonds. It is classified as an essential fatty acid because the human body cannot synthesize it in adequate quantities, making dietary or supplemental intake necessary. EPA is found primarily in marine sources and plays a central role in reducing systemic inflammation.

EPA is a precursor to a class of signaling molecules called eicosanoids — including prostaglandins, thromboxanes, and leukotrienes — that have anti-inflammatory properties. This contrasts with the pro-inflammatory eicosanoids derived from arachidonic acid, an omega-6 fatty acid. The balance between EPA and arachidonic acid in cell membranes significantly influences the body's inflammatory response.

Key Functions and Health Benefits

Research consistently associates adequate EPA intake with several health benefits:

  • Cardiovascular health: EPA reduces triglyceride levels (often by 20–50% at pharmacological doses), lowers resting heart rate, and reduces platelet aggregation, decreasing clot risk.
  • Anti-inflammatory effects: EPA competes with arachidonic acid for enzyme binding, reducing production of pro-inflammatory mediators.
  • Mental health: Clinical evidence supports EPA's role in reducing symptoms of depression and anxiety; meta-analyses suggest EPA-dominant formulations are more effective than DHA-dominant ones for mood disorders.
  • Immune modulation: EPA influences the activity of immune cells, including neutrophils and macrophages.

Health authorities such as the American Heart Association recommend consuming at least two servings of fatty fish per week, providing approximately 500 mg of combined EPA and DHA daily for healthy individuals.

Food Sources

FoodServing SizeEPA (mg)
Atlantic mackerel85 g~590
Wild salmon85 g~350–600
Canned sardines85 g~400
Rainbow trout85 g~290
Herring85 g~770

Algae-based EPA supplements provide a plant-derived alternative suitable for vegans and vegetarians.