Omega-3 Fatty Acids (EPA/DHA)

Essential anti-inflammatory fats that most people don't get enough of

Also known as: Fish Oil • EPA • DHA • Omega-3

other Names
Fish Oil, EPA, DHA, Marine Omega-3, Algal Oil
primary Benefits
Heart health, anti-inflammatory, brain function, mood support
common Dose
1–3g combined EPA+DHA daily
best Form
Triglyceride (TG) form fish oil or algal oil
timing
With a fat-containing meal
safety Rating
Very Safe

Overview

Omega-3 fatty acids — specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — are essential polyunsaturated fats that the body cannot produce and must obtain from diet or supplements. They are critical for brain function, cardiovascular health, and controlling inflammation throughout the body. The modern Western diet is severely imbalanced, with omega-6 to omega-3 ratios of 15:1 to 20:1 (optimal is 2:1 to 4:1). This imbalance promotes chronic inflammation, which underlies many modern diseases. Fish oil supplementation is one of the most well-studied interventions in nutritional science, with over 30,000 published studies.

Key Benefits

Cardiovascular Health

Omega-3s reduce triglycerides by 15–30%, lower blood pressure, reduce arterial plaque formation, and decrease the risk of arrhythmias. The REDUCE-IT trial showed high-dose EPA (4g/day) reduced cardiovascular events by 25%.

Anti-Inflammatory Effects

EPA and DHA are precursors to resolvins and protectins — specialized pro-resolving mediators that actively resolve inflammation. This makes omega-3s beneficial for inflammatory conditions including arthritis, IBD, and chronic pain.

Brain Health & Cognition

DHA makes up 40% of polyunsaturated fatty acids in the brain. Adequate omega-3 intake supports cognitive function, memory, and may reduce the risk of cognitive decline. DHA is particularly important during pregnancy for fetal brain development.

Mood & Mental Health

Meta-analyses show omega-3 supplementation (particularly EPA-dominant formulas) can reduce symptoms of depression with effect sizes comparable to some antidepressant medications. EPA at 1–2g/day shows the strongest evidence.

Dosage & How to Take

General health: 1g combined EPA+DHA daily. For specific conditions, higher doses of 2–4g may be needed. Always look at the EPA+DHA content, not total fish oil weight.

PurposeDoseNotes
General health1g EPA+DHA/dayMinimum effective dose for cardiovascular protection
Anti-inflammatory2–3g EPA+DHA/dayHigher EPA ratio preferred
Depression/mood1–2g EPA/dayEPA-dominant formulas (>60% EPA) most effective
Triglyceride reduction2–4g EPA+DHA/dayUnder medical supervision for high doses

Best Time to Take

Take with the largest meal of the day (containing fat) for best absorption. Splitting into 2 doses reduces fishy burps.

With or Without Food

Always take with a fat-containing meal. Absorption increases by 300% compared to taking on an empty stomach.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Triglyceride (TG) Fish OilHighGeneral supplementationNatural form found in fish. 70% better absorbed than ethyl ester.
Ethyl Ester (EE) Fish OilModerateBudget optionMost common form. Requires conversion back to TG for absorption.
Algal Oil (Vegan)HighVegans and vegetariansDHA-rich, some products also contain EPA. Sustainable source.
Krill OilHighThose who want phospholipid-bound omega-3sContains astaxanthin. Lower total EPA+DHA per capsule.

Side Effects & Safety

Common

  • Fishy burps/aftertaste
  • Mild GI upset
  • Loose stools at high doses

Rare

  • Increased bleeding time (at very high doses)
  • Fishy body odor

Contraindications

  • Fish/shellfish allergy (use algal oil)
  • Blood thinning medications (consult doctor at >3g/day)
  • Scheduled surgery (stop 1–2 weeks before)

Interactions

Blood thinners (Warfarin)Important

Omega-3s have mild blood-thinning effects. May enhance anticoagulant activity at high doses (>3g/day).

Vitamin DBeneficial

Fish oil enhances vitamin D absorption. Complementary pairing.

Vitamin EModerate

Omega-3s may increase vitamin E requirements due to increased PUFA oxidation. Many quality fish oils include vitamin E.

Scientific Research

2019New England Journal of Medicine

REDUCE-IT Trial

High-dose EPA (4g/day icosapent ethyl) reduced cardiovascular events by 25% in statin-treated patients with elevated triglycerides.

2019Translational Psychiatry

Omega-3 and Depression

Meta-analysis of 26 RCTs found EPA-predominant formulas (≥60% EPA) significantly reduced depressive symptoms (SMD = -0.61).

Food Sources

Salmon
Mackerel
Sardines
Anchovies
Herring
Walnuts (ALA)
Flaxseeds (ALA)
Chia seeds (ALA)

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.