Omega-3 from seafood
Fish remains the most efficient way to get preformed EPA and DHA. Here is the full table — species by species — with notes on cooking, mercury, and sustainability.
Why preformed EPA+DHA matters
EPA and DHA from fish and algae arrive in your body in the same form your cells use. Plant sources — flax, chia, walnuts — contain ALA (alpha-linolenic acid), which your body has to convert into EPA and then into DHA. That conversion is inefficient: typically less than 10% of ALA becomes EPA, and less than 1% reaches DHA. For Index purposes, a milligram of fish-sourced EPA+DHA is worth roughly 10–100× a milligram of ALA.
The full table
| Species | EPA (mg/100g) | DHA (mg/100g) | Total | Tier |
|---|---|---|---|---|
| Atlantic Salmon (farmed) | 690 | 1,457 | 2,147 | High |
| Anchovies | 763 | 1,292 | 2,055 | High |
| Herring | 909 | 1,105 | 2,014 | High |
| Atlantic Salmon (wild) | 411 | 1,429 | 1,840 | High |
| Tuna (Bluefin, fresh) | 309 | 970 | 1,279 | High |
| Atlantic Mackerel | 504 | 699 | 1,203 | High |
| Rainbow Trout (farmed) | 334 | 820 | 1,154 | High |
| Sardines (canned in oil) | 473 | 509 | 982 | High |
| Mussels | 276 | 506 | 782 | High |
| Oysters | 274 | 210 | 484 | Moderate |
| Barramundi | ~120 | ~280 | ~400 | Moderate |
| Snapper | ~95 | ~225 | ~320 | Moderate |
| Tuna (canned, light, in water) | 44 | 223 | 267 | Moderate |
| Prawns / Shrimp | 50 | 144 | 194 | Low |
| Cod | 4 | 120 | 124 | Low |
Tier thresholds: High >500 mg, Moderate 200–500 mg, Low <200 mg total EPA+DHA per 100 g serving.
Cooking & preservation effects
- Canning in oil — preserves EPA and DHA well; the oil locks in fatty acids.
- Canning in water — some EPA/DHA leaches into the liquid; drain less aggressively to retain it.
- Grilling, baking, poaching — preserve fatty acids well.
- Deep-frying — reduces omega-3 content and adds omega-6 from frying oils (worse for your ratio).
- Cold-smoking — preserves fatty acid content; hot-smoking has a small impact.
Practical guidance
The Heart Foundation recommends 2–3 servings of oily fish per week. Quick maths: two 150 g servings of farmed Atlantic salmon equals about 6,440 mg of EPA+DHA per week, or roughly 920 mg/day averaged out — meaningful contribution toward the optimal range, often enough to cover diet alone if combined with the occasional tin of sardines.
Mercury, microplastics, sustainability
Smaller and shorter-lived species — sardines, anchovies, mackerel, herring — concentrate less mercury than long-lived predators like bluefin tuna or large kingfish, and they sit higher on the EPA+DHA list too. FSANZ guidance recommends pregnant women limit large predatory fish in particular.
On sustainability: salmon farming varies widely. Look for ASC (Aquaculture Stewardship Council) certification, or for wild fisheries look for MSC. Tasmanian Atlantic salmon producers are subject to growing scrutiny — check current ratings on the AMCS Sustainable Seafood Guide.
Values from USDA FoodData Central and Food Standards Australia New Zealand (FSANZ) AUSNUT 2011–13. EPA and DHA content varies by season, diet, and species line; figures with a tilde indicate broader ranges in the literature.