How much fish do I need to eat to get enough omega-3?

November 8, 2025 •

3 min read

According to the American Heart Association (AHA), eating two servings of fatty fish per week is an effective way to obtain enough omega-3 fatty acids for a heart-healthy diet. The exact amount of fish needed depends on the type of fish and an individual's specific health needs, but this recommendation is a solid starting point for most adults.

Quick Summary

This guide details the recommended intake of fish to achieve adequate omega-3 levels, identifying which fish are highest in beneficial EPA and DHA. It clarifies serving sizes, provides a comparison of omega-3 content in various fish, and weighs the pros and cons of supplements versus whole foods to help optimize dietary intake.

Key Points

Consume Fatty Fish Twice a Week: The American Heart Association recommends two 3-4 ounce servings of fatty fish like salmon or mackerel per week for healthy adults.
Best Fish Sources: Oily, cold-water fish such as salmon, mackerel, sardines, and herring are the richest sources of beneficial EPA and DHA omega-3s.
Choose Low-Mercury Fish: Pregnant women, breastfeeding mothers, and children should opt for fish lower in mercury, such as salmon, trout, and canned light tuna.
Food Over Supplements: Health experts generally recommend obtaining omega-3s from whole fish rather than supplements, as fish provides a broader range of nutrients.
Check Omega-3 Content: Omega-3 levels vary significantly by fish species; high-fat fish contain the most, while canned tuna has lower levels.
Consult a Professional: Discuss specific dietary needs, including supplement use, with a healthcare provider, especially if you have heart disease or are pregnant.

The Importance of Omega-3 Fatty Acids

Omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are crucial polyunsaturated fats that the body cannot produce efficiently on its own. These essential nutrients are vital for maintaining heart health, brain function, and normal growth and development. Regular consumption is linked to reduced risk of heart disease, lower triglyceride levels, and support for cognitive health. While some plant sources contain alpha-linolenic acid (ALA), the conversion rate to the more beneficial EPA and DHA is low, making fish the most effective dietary source.

General Recommendations for Healthy Adults

For the average healthy adult, leading health organizations provide clear guidelines. The American Heart Association (AHA) advises consuming at least two servings of fatty fish per week. A single serving is typically defined as 3 to 4 ounces, or about ¾ cup, of cooked fish. This level of intake provides a sufficient quantity of EPA and DHA for maintaining overall health, particularly cardiovascular well-being. Incorporating fish like salmon, mackerel, and sardines into your meals twice weekly can effectively meet this recommendation.

Which Fish Offer the Most Omega-3?

Not all fish are created equal when it comes to omega-3 content. Fatty, cold-water fish are the richest sources of the beneficial EPA and DHA. Here is a list of some of the best choices:

Salmon: An excellent and popular source, with both wild and farmed varieties offering high levels of EPA and DHA.
Mackerel: These small, oily fish are nutrient-dense and an exceptionally high source of omega-3s.
Sardines: These small, canned fish are convenient, affordable, and packed with almost every nutrient the body needs, including high levels of omega-3s.
Herring: Often sold canned, pickled, or smoked, herring is a great source of omega-3s and vitamin B12.
Anchovies: Tiny but mighty, anchovies deliver a significant amount of EPA and DHA in a small portion.
Cod Liver Oil: While a supplement, this oil is a potent source of omega-3s, and also provides a substantial dose of vitamins D and A.

Special Considerations: Pregnancy, Children, and High Mercury Fish

Certain populations, like pregnant and breastfeeding women and young children, have specific dietary needs and should be mindful of mercury levels in fish. The US FDA and EPA provide guidance to maximize the nutritional benefits while minimizing exposure to contaminants. For instance, these groups should aim for 8 to 12 ounces of lower-mercury fish per week and avoid high-mercury species. Fish such as shark, swordfish, and king mackerel are known to have higher mercury levels and should be limited or avoided entirely. Canned light tuna is a safer choice than albacore tuna due to its lower mercury content.

Comparison: Omega-3 Content in Common Fish (per 3-ounce cooked serving)


Fish Type	EPA + DHA (mg)	Mercury Concerns	Notes
Atlantic Salmon	1,830	Low	Excellent all-around choice.
Canned Sardines	1,190	Very low	Convenient and affordable.
Atlantic Mackerel	1,600	Low	A nutrient powerhouse.
Canned Light Tuna	170	Low	Lower in omega-3s but very low mercury.
Albacore Tuna (canned)	1,300	Higher	Limit intake due to mercury.
Wild Rainbow Trout	840	Low	Great freshwater option.

The Debate: Supplements vs. Food

While omega-3 supplements, such as fish oil capsules, can be a convenient way to boost intake, most experts agree that getting omega-3s from whole food sources like fish is preferable. Whole fish contains a complete package of beneficial fats, high-quality protein, vitamins, and minerals that work synergistically. Some research suggests that the full spectrum of health benefits from eating fish can't be replicated with supplements alone. Furthermore, some studies on supplements have yielded mixed results regarding heart disease prevention in healthy individuals. It is always best to consult a healthcare provider before starting any new supplement regimen, especially if you have pre-existing health conditions or take other medications.

Conclusion

To get enough omega-3 fatty acids, most healthy adults should aim to eat two servings of fatty fish per week. Excellent choices include salmon, mackerel, and sardines, which offer high levels of EPA and DHA with relatively low mercury concerns. While supplements are an option, especially for those who don't eat fish, a whole-food approach is widely considered the superior method for maximizing health benefits. Always balance your fish consumption by choosing low-mercury varieties and consider specific guidelines for vulnerable populations, like pregnant women and children. By making informed choices, you can effectively integrate fish into a healthy diet to support your body and mind. For more detailed information on specific nutrient values, you can consult reliable sources such as the National Institutes of Health Office of Dietary Supplements.

Frequently Asked Questions

For optimal heart health, the American Heart Association recommends that healthy adults eat at least two 3-4 ounce servings of fatty fish per week.

The fish with the highest levels of beneficial EPA and DHA omega-3s are fatty, cold-water species such as salmon, mackerel, herring, and sardines.

Yes, but they should choose low-mercury options. The FDA and EPA recommend that pregnant women and children consume 8 to 12 ounces per week of fish like salmon, trout, and canned light tuna, while avoiding high-mercury fish.

Canned light tuna contains some omega-3s but significantly less than fatty fish like salmon. Albacore tuna has more omega-3s but also higher mercury levels, so it should be consumed in moderation.

While supplements can provide a concentrated dose of EPA and DHA, most experts recommend whole food sources. Fish provides a more complete nutritional profile and studies show stronger health benefits from dietary intake compared to supplements alone.

Fatty fish, which are higher in omega-3s, typically include salmon, mackerel, sardines, and herring. Lean fish, with lower omega-3 content, include cod, haddock, and tilapia.

Fish can contain traces of mercury, with larger, predatory fish like shark and swordfish having the highest levels. The health benefits of eating fish generally outweigh the risks for most people, especially when choosing a variety of fish and favoring lower-mercury options.