Which shellfish are high in omega-3?

November 13, 2025 •

4 min read

According to the National Institutes of Health, seafood is a crucial source of omega-3 fatty acids, but not all species are equal. While fatty fish often get all the praise, certain types of shellfish are also excellent sources of this essential nutrient, offering a delicious alternative to diversify your diet.

Quick Summary

This article explores the omega-3 content of various shellfish, ranking popular choices like mussels, oysters, and crab. It details the specific amounts of EPA and DHA found in these options and provides a comparative look at their overall nutritional value, highlighting their role in a healthy diet.

Key Points

Mussels are a top shellfish source: Farmed mussels can provide up to 800 mg of EPA/DHA per 100 grams, making them a highly effective way to increase omega-3 intake.
Oysters are rich in omega-3 and zinc: A 3-ounce serving of oysters offers a significant amount of omega-3s and nearly 100% of the daily value for zinc.
Not all shellfish contain equal amounts: While all shellfish have some omega-3s, levels are lower in species like clams and shrimp compared to mussels and oysters.
Cooking method is crucial for retention: Gentle cooking methods like steaming, poaching, or baking are best for preserving omega-3s, while high-heat frying can destroy them.
Incorporate a variety of seafood: For optimal health, aim for a diverse intake of seafood, including both oily fish and shellfish, to ensure a balanced nutritional profile.
Health benefits are widespread: The omega-3s in shellfish support heart health, brain function, and immune system strength through their anti-inflammatory properties.

Ranking Shellfish by Omega-3 Content

While most people associate omega-3s primarily with oily fish like salmon, many types of shellfish can also contribute significantly to your daily intake. The key is understanding which varieties offer the most EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two most beneficial forms of omega-3. A cooked 3-ounce serving is typically used for comparison, though omega-3 levels can fluctuate based on diet and source (wild vs. farmed).

Mussels

As one of the top shellfish sources, mussels provide a substantial amount of omega-3s per serving. Farmed mussels, in particular, can offer between 300 to 800 mg of EPA/DHA per 100 grams cooked weight, making them a powerhouse among bivalves. They also deliver high doses of protein, vitamin B12, and selenium. Mussels are an accessible and affordable option for those looking to boost their omega-3 intake without relying solely on fish.

Oysters

Oysters are another impressive source of omega-3 fatty acids, often containing ALA, EPA, and DHA. A 3-ounce serving of oysters can provide a significant portion of the recommended daily intake of omega-3s. Beyond healthy fats, oysters are celebrated for their exceptionally high zinc content, a mineral vital for immune function. This makes them a nutrient-dense choice that supports overall health in multiple ways.

Crab

Crab offers a respectable amount of omega-3s, with the exact content varying by species. For example, blue crab contains a good level of EPA/DHA per 3-ounce portion, while Dungeness crab has slightly less. Crab is also a rich source of lean protein and minerals like zinc, making it a healthy addition to your meals.

Scallops

Scallops also contribute omega-3s, although at lower concentrations compared to mussels and oysters. Still, a 3-ounce portion offers a valuable amount of EPA/DHA. They are low in fat and high in protein, providing essential nutrients without excessive calories.

Clams

Clams contain omega-3 fatty acids, but typically less than mussels or oysters. Despite the lower omega-3 content, clams are a good source of iron, and they are a delicious, low-calorie protein option.

Comparison of Common Shellfish Omega-3 Content

For a clearer picture, this table compares the approximate omega-3 content of several popular shellfish options based on a cooked 3-ounce (85-gram) serving size. Note that these values can vary.


Shellfish Type	Approximate Omega-3 (EPA/DHA) per 3 oz. cooked	Notable Additional Nutrients
Mussels (farmed)	300–800 mg	Vitamin B12, Zinc, Protein
Oysters	670 mg per 3 oz	Zinc, Iron, Vitamin B12
Blue Crab	403 mg	Lean Protein, Zinc
Scallops	310 mg	Low-Fat Protein, Magnesium
Clams	241 mg	Iron, Vitamin B12
Shrimp	240 mg	Low-Calorie Protein, Selenium

Benefits of Incorporating Shellfish with Omega-3s

Consuming shellfish high in omega-3s offers numerous health benefits beyond simple fatty acid intake. These nutrients are critical for a healthy body and mind.

Heart Health

Omega-3s are well-documented for their role in supporting cardiovascular health. They can help reduce blood clotting, lower triglyceride levels, and decrease blood pressure. Regular intake of shellfish has been linked to a reduced risk of heart-related issues.

Brain and Cognitive Function

DHA, one of the primary omega-3s in shellfish, is a vital structural component of the brain and eyes. Adequate intake supports cognitive function, memory, and may help protect against age-related cognitive decline.

Anti-Inflammatory Effects

Chronic inflammation is a driver of many diseases. The anti-inflammatory properties of EPA and DHA in shellfish can help manage conditions like rheumatoid arthritis and may contribute to overall cellular health.

Immune System Support

Many shellfish, particularly oysters, are packed with zinc. This mineral is essential for developing and maintaining immune cells, helping to fortify the body's natural defenses against illness.

How to Prepare Shellfish to Maximize Omega-3 Retention

The cooking method significantly impacts the retention of beneficial nutrients, including omega-3s. Gentle cooking methods that avoid high heat are recommended.

Steaming: Considered one of the best methods for preserving omega-3s, steaming uses gentle, moist heat.
Poaching: Similar to steaming, poaching cooks shellfish in a liquid at a low temperature, which helps maintain nutritional integrity.
Baking: Baking at lower temperatures can also preserve omega-3 fatty acids effectively.
Avoid Frying: Deep-frying and high-heat pan-frying can significantly reduce omega-3 content and introduce unhealthy fats.

Conclusion

While fatty fish are the richest source, several types of shellfish, particularly mussels and oysters, are excellent sources of omega-3 fatty acids, along with other essential nutrients like zinc and vitamin B12. Incorporating a variety of seafood, including shellfish, into your diet is a smart strategy for boosting your intake of these healthy fats. By choosing nutrient-dense options and opting for gentle cooking methods like steaming or baking, you can maximize the health benefits for your heart, brain, and overall well-being. Always consider your dietary needs and preferences when selecting which shellfish are high in omega-3 to add to your meals. For more detailed information on omega-3 sources and health recommendations, consult resources from authoritative bodies like the National Center for Complementary and Integrative Health (NCCIH).

Frequently Asked Questions

Mussels generally contain the highest levels of omega-3 fatty acids among common shellfish. Farmed mussels, for instance, can provide a very high concentration of EPA and DHA per serving.

Yes, the long-chain omega-3s (EPA and DHA) found in shellfish are the same beneficial types found in fatty fish. However, the total amount in shellfish is typically lower than in the richest oily fish like salmon.

While shellfish can be a great contributor, relying solely on it may not be enough to meet optimal omega-3 levels for most people. Combining shellfish with other sources like oily fish, nuts, and seeds is the most effective approach.

Mussels tend to have a higher overall quantity of omega-3s per serving than oysters. However, oysters are exceptionally rich in zinc, which provides other significant health benefits.

The cooking method matters significantly. Gentle methods like steaming, baking, or poaching preserve omega-3s well, while high-heat cooking like frying can destroy a large portion of them.

The omega-3s found in shellfish support heart health by lowering triglycerides, boost brain function, reduce inflammation, and enhance immune system activity.

While there's no single recommendation, research suggests that consuming omega-3-rich seafood multiple times per week is beneficial. Regular, moderate consumption as part of a varied diet is a good strategy.