What Fish Is a Superfood? A Complete Guide to the Healthiest Seafood

January 1, 2026 •

4 min read

The American Heart Association recommends eating fish at least twice a week for heart health, highlighting fatty fish as key sources of vital omega-3s. When it comes to nutrition, a few species stand out from the rest, making many wonder: what fish is a superfood, and which ones should you add to your plate for maximum benefits?

Quick Summary

This guide details the top fish superfoods like salmon, sardines, and mackerel, emphasizing their high levels of omega-3 fatty acids, protein, vitamin D, and essential minerals. It outlines how to choose the healthiest and most sustainable options for a nutritious diet.

Key Points

Oily fish are superfoods: Species like salmon, sardines, and mackerel are exceptionally rich in omega-3 fatty acids, vitamin D, and high-quality protein.
Salmon is a top choice: This fish is celebrated for its high omega-3 content, protein, vitamins D and B12, and antioxidant astaxanthin, supporting heart and brain health.
Sardines offer concentrated nutrition: These affordable and low-mercury fish pack more omega-3s and calcium (with bones) per gram than many larger species, promoting bone and heart health.
Mackerel is excellent for immunity: Atlantic mackerel is rich in omega-3s, B vitamins, and selenium, which help boost energy and support the immune system.
Choose wisely to minimize mercury: Opt for smaller fish like sardines and Atlantic mackerel for lower mercury levels, and always check for sustainable sourcing certifications.
Healthy cooking methods are best: Baking, grilling, or steaming fish helps preserve its nutritional value without adding unnecessary unhealthy fats.

Why Oily Fish Are Considered Superfoods

Fish, particularly the fatty, oily varieties, earn their superfood reputation by providing a dense concentration of vital nutrients that are difficult to obtain from other food sources. This nutritional profile makes them exceptional for supporting overall health. The primary benefits come from:

Omega-3 Fatty Acids: Oily fish are the richest source of marine-based omega-3s, specifically EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These essential fats are crucial for brain function, heart health, and reducing inflammation. Since the human body cannot produce these, we must get them from our diet.
High-Quality Protein: Fish provides a complete protein, containing all nine essential amino acids needed for muscle repair, immune system function, and metabolic balance.
Vitamin D: Few foods naturally contain vitamin D, but fatty fish like salmon and sardines are excellent dietary sources. This vitamin is vital for bone health, immune function, and regulating inflammation.
Essential Minerals: Fish offers an array of minerals, including iodine, zinc, selenium, phosphorus, and calcium. Selenium is a powerful antioxidant, and the calcium found in canned sardines (with edible bones) is a fantastic alternative to dairy.

The Top Contenders: A Closer Look

Several fish species are consistently lauded for their superior nutritional content.

Salmon

Wild-caught Alaskan salmon is often cited as a premier fish superfood. It is an excellent source of omega-3 fatty acids, high-quality protein, and vitamins D and B12.

Astaxanthin: The characteristic orange-red color of salmon comes from a powerful antioxidant called astaxanthin, which helps protect the body's cells from damage.
Wild vs. Farmed: While wild salmon may have a slightly higher omega-3 content, responsibly farmed salmon remains a highly nutritious and sustainable choice. Look for certifications like the Aquaculture Stewardship Council (ASC).

Sardines

These small, budget-friendly fish are nutritional powerhouses. A single can of sardines provides a significant amount of calcium (from the edible bones), vitamin D, and protein, along with marine-based omega-3s. Sardines also contain selenium, an antioxidant that protects cells from damage. As they are small and low on the food chain, they accumulate very little mercury, making them a safe choice for frequent consumption.

Mackerel

Atlantic mackerel is a small, oily fish that is another top-tier superfood. It is packed with omega-3s, B vitamins, and selenium. Its mild flavor makes it an excellent choice for those who are new to seafood. It is important to differentiate between Atlantic mackerel, which is low in mercury, and King mackerel, a larger fish with higher mercury levels that should be consumed sparingly.

Herring

Similar to sardines and mackerel, herring is a small, oily fish rich in omega-3s, vitamin D, and selenium. It's a staple in the Nordic diet and can be found canned, cured, or smoked, offering versatility.

Nutritional Comparison of Fish Superfoods


Fish Type	Omega-3s (EPA+DHA) per 3.5oz	Protein per 3.5oz	Vitamin D per 3.5oz	Mercury Level	Sustainability
Salmon (Wild Alaskan)	~2.7g	~25g	~7.3mcg	Low	Good, often certified
Sardines (Canned)	Higher than salmon per gram	~22.6g	~4.4mcg	Very Low	Excellent, highly sustainable
Mackerel (Atlantic)	Very High	~19g	Very High	Low	Good, check sourcing
Herring	Higher than mackerel/sardines/trout	~20g	Very High	Low	Varies by fishery, check sourcing
Tuna (Canned Light)	Good amount	~17g	Present	Low (Skipjack)	Good (Skipjack), check sourcing

Note: Nutritional values can vary based on species, preparation, and wild vs. farmed sourcing. Wild Alaskan salmon provides the highest amount of omega-3s among salmon varieties.

Cooking Methods and Recommendations

How you prepare your fish can impact its health benefits. The healthiest cooking methods preserve nutrients and avoid adding excess unhealthy fats.

Best Practices

Bake, Grill, or Broil: These methods are excellent for retaining omega-3 fatty acids and result in minimal added calories compared to frying. Simple seasonings like lemon, herbs, and spices can enhance the natural flavors.
Steam: Steaming is another low-calorie, healthy cooking option that helps retain the fish's natural flavors and moisture.
Avoid Deep Frying: Frying fish adds excessive calories and unhealthy fats, which can counteract the health benefits.

Sustainable Choices and Mercury

While the nutritional benefits are clear, it is also important to consider environmental impact and mercury content. Generally, smaller, shorter-lived fish like sardines, Atlantic mackerel, and canned light (skipjack) tuna have lower mercury levels. For larger fish like salmon and certain types of tuna, choosing wild-caught or sustainably farmed options from reputable suppliers is recommended. Organizations like the Marine Stewardship Council (MSC) and Monterey Bay Aquarium's Seafood Watch offer valuable guidance on sustainable seafood choices.

Conclusion: Adding Fish Superfoods to Your Diet

There isn't a single definitive answer to what fish is a superfood; rather, several oily, nutrient-dense fish deserve this title. Salmon, sardines, Atlantic mackerel, and herring are all fantastic choices rich in omega-3s, protein, and essential vitamins and minerals. Incorporating a variety of these fish into your diet, prepared with healthy cooking methods, can significantly contribute to heart health, brain function, and overall wellness. By being mindful of sustainability and mercury levels, you can make informed choices that are beneficial for both your health and the planet. For more inspiration, explore delicious, healthy fish recipes online, such as those found on trusted culinary sites.

Sources

**** American Heart Association. "Fish and Omega-3 Fatty Acids." https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/fish-and-omega-3-fatty-acids
**** AXA. "Superfood: A comprehensive look at the benefits, nutritional value, caloric content, and best pairings of salmon!" https://www.axa.com.hk/en/blog/health/superfood-a-comprehensive-look-at-the-benefits-nutritional-value-caloric-content-and-best-pairings-of-salmon
**** News-Medical. "Are Sardines Good for You? Health Benefits and Nutrition Explained." https://www.news-medical.net/health/Why-sardines-deserve-a-spot-on-your-plate-Surprising-health-benefits-of-this-tiny-fish.aspx
**** Verywell Fit. "Mackerel Nutrition Facts and Health Benefits." https://www.verywellfit.com/mackerel-nutrition-facts-and-health-benefits-5074868
**** Quora. "Which fish is highly nutritious?" https://www.quora.com/Which-fish-is-highly-nutritious

Frequently Asked Questions

No, while most fish are healthy, the term 'superfood' is best applied to fatty, oily fish like salmon and sardines that have the highest concentration of omega-3 fatty acids, vitamin D, and other key nutrients essential for optimal health.

Among commonly eaten varieties, oily fish such as salmon, mackerel, and sardines are some of the richest sources of marine-based omega-3 fatty acids (EPA and DHA), which are highly beneficial for heart and brain health.

Yes, canned versions of fish like sardines, salmon, and mackerel retain their superfood properties, including high levels of omega-3s and, in the case of sardines, extra calcium from the soft, edible bones.

Mercury is a concern with larger, predatory fish like king mackerel and bigeye tuna. Smaller, shorter-lived fish such as salmon, sardines, and Atlantic mackerel have very low mercury levels and are safe for regular consumption.

Wild salmon may have slightly higher omega-3s and fewer potential contaminants, but farmed salmon is also a highly nutritious and widely available option. For sustainability, look for certifications like the Aquaculture Stewardship Council (ASC).

For optimal health benefits, the American Heart Association recommends eating at least two servings (3.5 ounces cooked) of fatty fish per week to ensure an adequate intake of beneficial omega-3 fatty acids.

In addition to healthy fats, these fish are excellent sources of high-quality protein, vitamin D, B vitamins (especially B12), and essential minerals like selenium, iodine, and phosphorus, all of which are critical for bodily functions.

For pregnant women and young children, low-mercury options like salmon, sardines, and trout are recommended. These provide essential omega-3s for fetal brain development while minimizing mercury exposure.