What is the top 5 healthiest fish?

October 13, 2025 •

3 min read

According to the American Heart Association, eating fish at least two times per week is a critical component of a healthy diet, offering a wealth of omega-3 fatty acids and other nutrients. This guide answers the common question: what is the top 5 healthiest fish to incorporate into your meals?

Quick Summary

This article explores the five healthiest fish options, examining key factors like omega-3 fatty acid levels, mercury content, and sustainability. It provides a detailed comparison, nutritional benefits, and preparation tips to help you make informed choices for a balanced and heart-healthy diet.

Key Points

Atlantic Mackerel: High in omega-3s, vitamins B12 and D, and selenium, with very low mercury and excellent sustainability.
Wild-Caught Salmon: A prime source of omega-3s (DHA and EPA), protein, and vitamin D, with lower mercury than farmed varieties.
Sardines: A true superfood, providing omega-3s, vitamin D, and calcium (when bones are included), and featuring very low mercury.
Rainbow Trout: A mild-flavored freshwater fish rich in omega-3s, protein, and B vitamins, generally considered low in mercury and sustainably farmed.
Herring: A relative of the sardine, offering ample omega-3s, vitamin D, and B12, with low mercury and strong sustainability credentials.
Low Mercury is Key: Smaller, shorter-lived fish like these accumulate less mercury, making them safer for frequent consumption.
Prioritize Sustainability: Choosing sustainably sourced fish helps protect marine ecosystems and ensures future fish availability.
Diversify Your Intake: Eating a variety of these healthy fish ensures a broad spectrum of nutrients for optimal health.

Ranking the Top 5 Healthiest Fish

When evaluating the healthiest fish, experts consider three primary factors: omega-3 fatty acid content, low mercury levels, and sustainability. The following five fish consistently rank highest in these categories, offering excellent nutritional profiles with minimal risk.

1. Atlantic Mackerel (or Pacific Chub Mackerel)

Often overlooked, mackerel is a powerhouse of nutrition and sustainability. Atlantic mackerel, specifically, is a "best choice" according to the FDA due to its low mercury content and high omega-3 levels. A single 3-ounce cooked serving can contain over 1,000 mg of omega-3s, along with a rich supply of vitamin B12 and selenium. Its quick reproduction cycle and low position on the food chain make it a highly sustainable option.

2. Wild-Caught Salmon

Wild-caught salmon is a classic for a reason, prized for its high omega-3 concentration, including DHA and EPA, which are vital for brain and heart health. Wild varieties, like those from Alaska (Sockeye or Pink), tend to have lower mercury levels than some farmed options and are often certified as sustainably sourced. Salmon also provides a significant dose of protein and vitamin D.

3. Sardines

These small, inexpensive, oily fish are true superfoods. Sardines are high in omega-3s, vitamin D, and calcium, especially when canned with the bones. Their small size means they have extremely low mercury levels. Sardines are prolific and reproduce quickly, making them an excellent choice for sustainability. They are also a convenient, shelf-stable source of nutrients.

4. Rainbow Trout

As a freshwater fish, rainbow trout is known for its mild flavor and impressive health benefits. It contains a strong dose of omega-3 fatty acids and is an excellent source of protein, vitamin D, and B vitamins. Farmed rainbow trout, in particular, is often considered a highly sustainable choice. Its low mercury content makes it a safe option for regular consumption by most people.

5. Herring

Another small, oily fish, herring is closely related to sardines and offers similar nutritional advantages. It is packed with heart-healthy omega-3s, along with vitamin D, vitamin B12, and selenium. Herring is naturally low in mercury and is often caught using sustainable methods, making it a great eco-friendly choice. Its versatility allows it to be pickled, smoked, or eaten fresh.

Comparison Table: Top 5 Healthiest Fish


Feature	Atlantic Mackerel	Wild-Caught Salmon	Sardines	Rainbow Trout	Herring
Omega-3s (EPA+DHA)	Very High	Very High	Very High	High	Very High
Mercury Levels	Very Low	Low	Very Low	Very Low	Very Low
Protein	High	High	High	High	High
Vitamin D	Excellent Source	Excellent Source	Excellent Source	Excellent Source	Excellent Source
Calcium (with bones)	Low	Low	Very High	Low	Very High
Sustainability	Excellent	Excellent	Excellent	Excellent	Excellent

The Importance of Low Mercury and Sustainability

While omega-3 content is a major driver of fish's health benefits, it is crucial to consider both mercury content and sustainability. Large predatory fish, such as shark, swordfish, and certain types of tuna, accumulate high levels of mercury, which can be harmful, especially for pregnant women and young children. Choosing smaller, lower-mercury fish is a safer bet for frequent consumption. Furthermore, sustainable sourcing ensures that fish populations are not overfished and that ecosystems remain healthy, protecting the resource for future generations. Resources like the Marine Stewardship Council (MSC) and Seafood Watch can help identify sustainable options.

How to Incorporate These Fish into Your Diet

Including these top five healthiest fish in your meals is easier than you think. Mackerel, for example, can be grilled, baked, or added to salads. Wild salmon is perfect for baking, poaching, or grilling and can be served as a centerpiece or in a poke bowl. Canned sardines and herring are excellent budget-friendly options that can be mashed on toast, added to pasta, or eaten straight from the can. Rainbow trout's mild flavor makes it incredibly versatile; it can be pan-seared with herbs and lemon or baked with vegetables.

Conclusion

For those seeking the most nutritious and safe seafood options, focusing on oily fish that are low in mercury and high in omega-3s is a clear winning strategy. Our list of the top 5 healthiest fish—Atlantic mackerel, wild-caught salmon, sardines, rainbow trout, and herring—provides a fantastic starting point. By prioritizing these choices, you can improve your cardiovascular and cognitive health while also supporting sustainable fishing practices. Remember to check local advisories and choose certified sustainable options whenever possible to enjoy these benefits responsibly.

Visit the FDA's Advice About Eating Fish for additional information.

Frequently Asked Questions

Oily fish like mackerel, sardines, and wild-caught salmon are among the richest sources of omega-3 fatty acids, containing high levels of EPA and DHA.

Yes, canned sardines and mackerel are very healthy, offering a convenient and affordable source of omega-3s, protein, and other nutrients like vitamin D and calcium. Canning does not diminish their nutritional value significantly.

While both can be nutritious, wild-caught fish often has lower levels of contaminants like mercury and may have slightly different fat compositions. However, some responsibly farmed fish are excellent choices for both nutrition and sustainability.

You should limit or avoid high-mercury fish such as king mackerel, marlin, orange roughy, shark, and swordfish. Larger predatory fish tend to have higher concentrations of mercury.

The American Heart Association and Dietary Guidelines for Americans recommend consuming at least two servings of fish, especially fatty fish rich in omega-3s, per week.

Proper cooking methods like baking, grilling, or steaming have minimal impact on a fish's nutritional value. However, deep-frying can increase its fat content and calorie count.

Besides omega-3s, fish is an excellent source of high-quality protein, B vitamins (especially B12), vitamin D, and minerals like selenium, iodine, and potassium.