Omega-3 Calculator

Why omega-3 fatty acids matter

Omega-3 fatty acids, specifically EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), are essential polyunsaturated fats that your body cannot produce on its own. They must come from food or supplements. The NIH Office of Dietary Supplements recommends 1.1-1.6 g/day of alpha-linolenic acid (ALA) for adults, but most of the health benefits come from EPA and DHA, which are found primarily in fatty fish. The international consensus for EPA+DHA is 250-500 mg/day for general cardiovascular health, and 1-4 g/day for therapeutic use (triglyceride lowering, inflammation reduction).

Food sources of EPA and DHA

The best dietary sources are fatty cold-water fish: salmon (1.8 g per 3 oz), sardines (1.4 g), mackerel (1.2 g), herring (1.0 g), and anchovies (0.9 g). Plant-based sources (flaxseed, chia, walnuts) contain ALA, which converts to EPA and DHA at only 5-10% efficiency. For vegetarians and vegans, algae-based EPA/DHA supplements are the most reliable source. The omega-3 index, the percentage of EPA+DHA in red blood cell membranes, is the gold-standard biomarker, with 8-12% associated with lowest cardiovascular risk.

Health benefits supported by research

Omega-3s have strong evidence for cardiovascular protection: the REDUCE-IT trial showed that 4 g/day of prescription EPA (icosapent ethyl) reduced cardiovascular events by 25% in high-risk patients. Omega-3s also lower triglycerides (20-50% reduction at 3-4 g/day), reduce blood pressure modestly (2-5 mmHg), and may improve mood and cognitive function. The VITAL trial found that 1 g/day of EPA+DHA did not reduce cancer or cardiovascular events in healthy adults, suggesting that omega-3 supplementation is most beneficial for those with elevated risk or low dietary intake.

When to supplement

If you eat fatty fish at least twice per week, supplementation is generally unnecessary. If you don't eat fish, consider an algae-based EPA/DHA supplement (250-500 mg/day). If you have elevated triglycerides, cardiovascular disease, or rheumatoid arthritis, discuss higher-dose omega-3 therapy (2-4 g/day) with your clinician. Always choose third-party tested supplements (USP, NSF, IFOS) to ensure purity and potency, as fish oil is prone to oxidation.