Reference
This table provides EPA and DHA omega-3 content and mercury risk levels for common fish. Use it to choose fish that deliver the most omega-3 benefit at the lowest mercury risk.
Standard Definition
EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are the two omega-3 fatty acids with the strongest evidence for cardiovascular and anti-inflammatory benefit. They are found directly in oily fish and marine algae. Values below are for cooked fish unless noted.
Omega-3 Content of Common Fish (Per 3 oz / 85g Cooked)
| Fish | EPA + DHA (g) | Mercury Risk | Notes |
|---|---|---|---|
| Mackerel (Atlantic) | 2.5 | Low | Highest omega-3 of common fish |
| Salmon (wild, Atlantic) | 1.8 | Low | Widely available; consistent quality |
| Salmon (farmed, Atlantic) | 2.2 | Low | Higher omega-3 due to feed; comparable to wild |
| Herring | 1.7 | Low | Underutilized; affordable |
| Sardines (canned in oil) | 1.4 | Low | Shelf-stable; full omega-3 benefit |
| Anchovies | 1.0 | Low | High per calorie; used as flavoring |
| Rainbow trout (farmed) | 1.0 | Low | Mild flavor; practical for weeknight cooking |
| Tuna (bluefin) | 1.5 | High | Limit to once per week or less |
| Tuna (canned light) | 0.2 | Low–moderate | Lower omega-3; safer mercury option |
| Tuna (canned albacore) | 0.7 | Moderate | Higher omega-3 than light; moderate mercury |
| Swordfish | 0.9 | Very high | Avoid or limit severely — high mercury |
| Cod | 0.2 | Low | Lean fish; minimal omega-3 |
| Tilapia | 0.1 | Low | Very low omega-3; not a useful source |
| Shrimp | 0.3 | Low | Modest omega-3; nutritionally useful |
| Oysters | 0.5 | Low | Modest omega-3; rich in zinc and minerals |
Source: USDA FoodData Central; FDA/EPA fish consumption guidance
Default Use Pattern
For most adults targeting two to three weekly servings of oily fish: prioritize salmon, sardines, mackerel, or herring. All are low mercury with high EPA + DHA. Canned sardines and salmon deliver full benefit at the lowest cost.
Avoid or strictly limit swordfish, shark, king mackerel, and tilefish — all are very high mercury with no meaningful safety margin at regular consumption.
Mercury Risk Explained
Mercury risk reflects methylmercury accumulation — a neurotoxin that concentrates up the food chain. Fish that eat smaller fish accumulate more. Risk levels here follow FDA/EPA guidance categories:
- Low — safe at two to three servings per week for all adults
- Low–moderate — safe at two servings per week for most adults
- Moderate — limit to one serving per week
- High — limit to once per week or less; avoid during pregnancy
- Very high — avoid entirely or limit to once per month; avoid during pregnancy
Canned vs Fresh
Canning does not meaningfully reduce omega-3 content. Canned sardines, salmon, and tuna in oil retain full EPA and DHA. Canned fish in water retains slightly less due to some fat loss into the water, but the difference is small. Drain and rinse canned fish packed in brine to reduce sodium.
Connects To
- Fish Consumption and Omega-3 Intake — how often to eat fish and when plant-based alternatives apply
- Mediterranean Salmon — a simple recipe applying the highest-priority omega-3 fish
- Mediterranean Diet: How the Pattern Works — how fish fits into the full dietary pattern
- Mediterranean Diet Basics — the gateway guide to the Mediterranean knowledge system
- Olive Oil as a Default Cooking Fat — the fat that pairs with fish in Mediterranean cooking