Foods that Contain Fish Oil

November 23, 2025 •

4 min read

According to the American Heart Association, consuming at least two servings of fatty fish per week is an effective way to obtain beneficial omega-3s. These essential polyunsaturated fats, commonly known as fish oil, are critical for heart and brain health and cannot be efficiently produced by the human body. Integrating these foods into your diet is essential for your well-being.

Quick Summary

A varied diet including fatty fish like salmon and mackerel, shellfish, and certain fortified foods provides the beneficial omega-3s known as fish oil. Vegetarians and vegans can find plant-based alternatives, though absorption is less efficient. Focus on incorporating these nutrient-dense options to support cardiovascular and cognitive function.

Key Points

Rich Marine Sources: Fatty fish such as salmon, mackerel, herring, and sardines are the best dietary sources of EPA and DHA, the key omega-3s in fish oil.
Algae is the Origin: Fish acquire their omega-3s by consuming algae and other smaller marine life; algal oil is a vegan source of direct EPA and DHA.
Plant-Based Alternatives: Nuts and seeds like walnuts, flaxseeds, and chia seeds provide ALA, an omega-3 that the body can convert, albeit inefficiently.
Consider Fortified Products: Eggs, milk, and certain cereals are often fortified with omega-3s and can help increase your daily intake.
Food vs. Supplements: Getting omega-3s from whole foods is generally preferred over supplements, as food provides a wider range of beneficial nutrients.
Dietary Goal: The American Heart Association recommends two servings of fatty fish per week to obtain sufficient amounts of heart-healthy omega-3 fatty acids.

Oily, Cold-Water Fish: The Richest Sources

Oily, cold-water fish are the most potent natural sources of the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These two compounds are primarily responsible for the health benefits associated with fish oil. Consuming fresh, frozen, or tinned versions of these fish is highly recommended by dietary guidelines.

Top oily fish sources of EPA and DHA:

Salmon: A nutritional powerhouse, salmon is packed with high-quality protein, vitamins, and a significant amount of EPA and DHA. Wild-caught and farmed varieties both offer substantial omega-3 content.
Mackerel: A small, fatty fish often smoked or canned, mackerel is exceptionally rich in omega-3s, as well as vitamin B12 and selenium.
Sardines: These small, oily fish are commonly sold canned and are full of nutrients, including nearly every essential nutrient your body needs when eaten whole.
Herring: Frequently sold pickled or cold-smoked, herring is a great source of both EPA and DHA and is a popular breakfast choice in some regions.
Anchovies: These tiny, flavor-packed fish contain high levels of omega-3s. They are often used to flavor sauces or as toppings on pizzas and salads.
Trout: Another excellent source, especially freshwater trout, provides a significant dose of omega-3s per serving.

Shellfish and Other Marine Life

Beyond the classic oily fish, other seafood options also provide valuable EPA and DHA, although typically in smaller amounts. Regular consumption of these can still contribute significantly to your overall omega-3 intake.

Oysters: As a shellfish, oysters are uniquely rich in all three major omega-3 types, including ALA. They are also an exceptional source of zinc and vitamin B12.
Shrimp: Widely consumed around the world, shrimp contain modest amounts of EPA and DHA along with protein and potassium.
Crab: Fresh crab meat is a good source of omega-3s and can be incorporated into various meals.
Caviar: The eggs, or roe, of fish are known for their high omega-3 content, making them a rich but typically less common source.

Plant-Based and Fortified Omega-3 Sources

While fish oil specifically refers to fatty acids from fish, it's important to recognize that the EPA and DHA in fish originally come from micro-algae and plankton. Plant-based sources contain a different type of omega-3, alpha-linolenic acid (ALA), which the body can convert into EPA and DHA, but often inefficiently. This is why marine sources are preferred for those seeking optimal EPA and DHA intake, though plant-based sources are still beneficial and necessary, especially for vegetarians and vegans.

Seeds: Flaxseeds, chia seeds, and hemp seeds are outstanding sources of ALA. Grinding flaxseeds before consumption improves nutrient absorption.
Walnuts: These nuts are rich in ALA and also contain fiber, copper, manganese, and vitamin E.
Algae Oil: Directly sourced from algae, this oil provides EPA and DHA and is an ideal supplement for those on a vegetarian or vegan diet.
Fortified Foods: Many products have omega-3s added, such as eggs, milk, soy beverages, yogurt, and infant formulas. Checking the nutrition label is key to identifying these products.

Comparison of Omega-3 Sources


Source Type	Examples	Omega-3 Type	Absorption/Efficiency	Best For	Potential Downsides
Fatty Fish	Salmon, Mackerel, Sardines	EPA and DHA	Very High	Direct and efficient intake of EPA and DHA.	Higher mercury risk in some species; not suitable for vegans/vegetarians.
Shellfish	Oysters, Crab, Shrimp	EPA, DHA, and ALA	Moderate to High	Varied nutrient profile, good option alongside fatty fish.	Contains lower levels of EPA/DHA than oily fish; not vegan.
Plant Seeds	Flaxseed, Chia Seeds	ALA (must be converted)	Low Conversion Rate	Excellent for ALA intake, fiber, and other nutrients.	Not efficient for boosting EPA and DHA levels.
Algae Oil	Algal oil	EPA and DHA	High	Vegans/vegetarians seeking direct EPA and DHA.	May offer lower dosages than fish oil supplements.
Fortified Foods	Eggs, Dairy, Cereals	Varies (ALA, DHA)	Varies	Convenient addition to everyday diet.	Less potent; requires checking labels; amounts can be inconsistent.

Cooking with Omega-3-Rich Foods

Incorporating omega-3s into your diet is straightforward. For oily fish, simple cooking methods like grilling, baking, or pan-searing help retain nutrients. To get more ALA, ground flaxseed and chia seeds can be sprinkled into oatmeal, yogurt, and smoothies. Cooking with certain oils like canola or flaxseed oil can also help increase intake, though flaxseed oil should not be heated due to its low smoke point. For those seeking an efficient vegan option, algal oil offers preformed EPA and DHA without the need for conversion.

Conclusion

Fish oil and the omega-3 fatty acids it contains are vital for maintaining good health, particularly for the heart and brain. While the most direct and potent sources of EPA and DHA come from fatty fish like salmon and mackerel, there are many alternatives for those with dietary restrictions or preferences. By diversifying your intake across oily fish, certain shellfish, and plant-based ALA sources, you can effectively meet your body's omega-3 needs. For the highest bioavailability of EPA and DHA outside of eating fish, algal oil is a powerful option. Always consider variety and sustainability when building a nutrient-rich diet. For more information on omega-3s and heart health, visit the American Heart Association.

Frequently Asked Questions

Oily, cold-water fish are the richest sources of omega-3s. Examples include mackerel, salmon, herring, and sardines, which contain high levels of EPA and DHA per serving.

While plant-based foods like flaxseeds, chia seeds, and walnuts contain ALA (a type of omega-3), they do not contain fish oil itself. The body converts ALA into EPA and DHA, but this process is not very efficient.

Fortified foods like certain eggs, milk, and yogurts can contribute to your omega-3 intake, but they generally provide much lower and less potent amounts of EPA and DHA compared to fatty fish.

Yes, canned oily fish such as sardines, salmon, and herring are excellent and convenient sources of omega-3 fatty acids. It is important to check the label for sodium content, especially if tinned in brine.

EPA and DHA are long-chain omega-3s found mainly in marine sources (fish, algae). ALA is a short-chain omega-3 found in plant sources. The body can convert ALA into EPA and DHA, but the conversion is limited, making marine sources more direct for EPA and DHA.

Some fish, particularly larger predatory types like king mackerel and swordfish, can contain higher levels of mercury. To minimize exposure, health experts recommend eating a variety of lower-mercury fish like salmon, anchovies, and sardines.

Most experts recommend obtaining omega-3s from whole foods first. Eating fish and other seafood provides a broader spectrum of nutrients, including protein, vitamins, and minerals, in addition to EPA and DHA.