Fish is one of the healthiest sources of protein around. Filled with omega-3 fatty acids and essential vitamins and minerals, it’s a great addition to any whole-food, plant-based diet. The American Heart Association (AHA) even recommends eating two servings of fish per week. But with so many options, you have to wonder: What is the healthiest fish of all?
The Best Fish?
Well, all fish is a source of heart-healthy omega-3s, a group of polyunsaturated fatty acids your body cannot make on its own. They can help lower your blood pressure, reduce inflammation in your blood vessels, and prevent blood clotting that could lead to strokes.
Fish contains multiple other nutrients your body needs to function at its best, including:
- Iodine: For proper thyroid function, including regulating metabolism.
- Vitamin D: For calcium absorption as well as bone growth and health.
- Vitamin B12: For well-functioning nerves and red blood cell formation.
- Selenium: For thyroid support and decreased oxidative stress in the body.
But fish can also be a source of contaminants like mercury. This toxic heavy metal makes its way into the water supply through household and industrial pollution, where fish absorb it through their food and habitat.
Yet some species of fish contain higher amounts of the compound than others. You just have to know what to look for.
You’ll also want to consider the source—farm-raised or wild-caught? Local or imported?
So, there’s more than just nutritional value to think about when selecting the best fish. And we’re here to take some of the guesswork out of it.
Before you head to the fish market, have a look at our list of some of the healthiest fish (and the worst fish) on earth.
The 6 Healthiest Fish to Eat
Salmon has a spot on “healthiest food” lists everywhere, and for good reason. This pink-fleshed fish is loaded with B vitamins, minerals, and the antioxidant astaxanthin.
One three-ounce serving offers 45% of the recommended daily value (DV) of vitamin B12, 35% DV of vitamin B6, 33% DV of niacin, and 44% DV of selenium.
But it’s the omega-3 content that keeps salmon on the minds of health experts year after year.
Oily salmon naturally contains the two most beneficial omega-3 fats: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In addition to life-saving heart benefits, these fatty acids have been linked to reduced risk of asthma, depression, age-related eye degeneration, and Alzheimer’s disease.
And when it comes to wild-caught vs. farm-raised, most consider wild-caught salmon to be superior. It has greater nutritional value and lower concentrations of contaminants, antibiotics, and pesticides.
However, farm-raised is much more affordable, and the beneficial nutrients are still there—just in smaller amounts. So, the general consensus is to eat wild if you can. And if it’s too pricey, the benefits of farmed salmon seem to outweigh the risks.
Try sticking to farm-raised varieties from developed countries such as the U.S., Canada, and Norway.
These bite-sized fish are also of the oily variety, with all the benefits of omega-3 fatty acids. Although, they do have unique advantages all their own.
Anchovies are low-calorie, high-protein, and brimming with flavor. Their nutrient density is pretty impressive as well.
In a three-ounce serving of anchovies, you’ll find:
- Niacin (a whopping 60% DV!)
- Selenium (44% DV)
- Iron (15% DV)
- Riboflavin (13%DV)
- Calcium (12% DV)
Niacin (vitamin B3) is critical for proper cell function and development, and helps your body turn the foods you eat into fuel. Selenium is associated with enhanced immune response and a lower risk of cancer.
Anchovies, like most small fish, are also low in mercury. This means that a moderate intake is likely safe.
Since anchovies are often salt cured, you will have to watch out for their high sodium content. To cut down on the salt, rinse them with water, or opt for an oil-packed brand.
Fresh is, of course, ideal and perhaps favorable for those who enjoy a milder taste.
Bonus tip: If you find that canned anchovies taste too fishy to eat as is, add them to sauces, marinades, pastas, and salads for an extra kick.
Speaking of mild-tasting fish, cod has a sweet, delicate flavor that’s pleasing to most. There’s a reason why it’s a go-to for beginners and people who “hate” fish.
It’s also a rich source of brain-boosting omega-3s and protein. Just three ounces provides 30% of the recommended DV of protein.
Protein is necessary for building and maintaining strong, healthy muscles and bones.
It’s true that the typical Western diet is in no way deficient in protein. But it’s usually lacking in high-quality protein sources. Lean, white cod is low in calories and “bad” cholesterol-raising saturated fat, unlike the more popular red meat.
And, as an animal-based protein, cod contains all nine essential amino acids. These are the building blocks of protein that you must get from your diet.
Moreover, cod is a good source of vitamins, including niacin, B6, B12, and D, as well as the minerals phosphorus, potassium, and selenium.
To top it off, cod is one of the few larger fish that doesn’t contain high levels of mercury.
Herring can be a bit of the best of both worlds. It’s got the subtle flavor of a flaky white fish with the omega-3 content of an oily catch.
The forage fish is a culinary staple in Northern Europe, where it’s found in abundance in the North Sea, Baltic Sea, and North Atlantic.
Locally, pickled herring is one of the most popular iterations of the sea fare.
While on the small-to-medium side, the “silver darling” is a powerhouse of vitamins D and B12. Three ounces will give you nearly 200% DV of the former and well over 300% DV of the latter.
If you’re one of the estimated 42% of American adults suffering from a vitamin D deficiency, maybe it’s time to add some herring to your menu.
As a smaller schooling fish with a short life span, it’s low in mercury and considered environmentally sustainable.
But do be cautious about eating herring eggs, as they’ve been known to transmit cholera.
Can’t resist a basket of fish and chips? Then you’re likely already a fan of haddock, the top choice of fish for the classic British dish.
Minus the deep-fried batter, haddock is a trim and healthy white fish with impressive protein content and a great omega-3 to omega-6 ratio.
Even though both polyunsaturated fats are essential, it’s important to maintain the proper balance between them. A diet that’s too high in omega-6 and too low in omega-3, for example, may contribute to inflammation and chronic disease.
Haddock has about 29 milligrams (mg) of omega-3 per 1 mg of omega-6. So, it can add to your daily omega-3 count while limiting your omega-6 intake.
In a three-ounce serving, there are also good amounts of B vitamins (niacin, B6, and B12) and minerals like phosphorus. Phosphorus works with calcium to build strong bones and also plays a role in generating energy.
Plus, this fish is yet another low-mercury option.
Sardines are often confused with anchovies—the other small, oily, saltwater fish on our list. But they’re actually two different species. Sardines belong to the family Clupeidae (which includes herring), while anchovies come from the Engraulidae family.
Aside from being less pungent, sardines are also larger and lighter-fleshed than anchovies. They’re higher in omega-3 fatty acids, too. In fact, they have one of the highest concentrations of omega-3s of any fish.
Unlike anchovies, they’re commonly eaten whole, which allows for maximum nutrient consumption.
The fish are especially high in calcium and vitamin B12, two nutrients that work together to ensure optimal bone health.
Just remember to avoid sardines canned in soybean oil; they’re likely to feature unhealthy amounts of omega-6 fatty acids.
The 7 Worst Fish to Eat
Not all fish is good fish. But how do you know what to look for?
In addition to its place of origin, consider where the fish sits on the food chain. The biggest fish in the pond typically have the highest mercury levels—because they eat lots of smaller fish containing mercury.
They also tend to live longer, so the mercury has more time to accumulate in their body.
You should also beware of fish imported from countries with less stringent safety standards. They may contain antibiotics, pesticides, cancer-causing polychlorinated biphenyls (PCBs), and other substances that are banned in North America.
Furthermore, according to some reports, the U.S. Food and Drug Administration (FDA) is less likely to thoroughly inspect them.
With all of this in mind, here’s a list of seven fish to avoid:
- King mackerel
- Orange roughy
Per the FDA and the U.S. Environmental Protection Agency, these large, predatory fish contain the highest levels of mercury. Children and pregnant or nursing women should never eat them. Adult women and men should consume no more than one serving per month.
Methylmercury, a very toxic form of mercury found in fish, can cause severe neurological problems, including cognitive and muscle dysfunction. It’s especially harmful to developing fetuses and infants.
Dangers may be lurking in your local fishing hole as well.
If you prefer to catch your own fish, or eat fish caught by family and friends, be sure to check your community advisories for the most relevant and up-to-date information on potential fish contaminant exposure.
Consumer guides like the Monterey Bay Aquarium’s Seafood Watch can provide you with further details on different species and their sustainability.
Choose Your Fish Wisely
Fish is a high-quality protein with so many health benefits to offer. It’s why more and more people are looking to add it into their weekly dinner rotation. But not all fish is created equal.
Keep yourself informed of the potential dangers so that you can choose the healthiest fish for you and your family.
“Advice about Eating Fish,” U.S. Food & Drug Administration; https://www.fda.gov/food/consumers/advice-about-eating-fish, last accessed March 15, 2021.
Menon, S., “Mercury Guide,” NRDC, March 10, 2016; https://www.nrdc.org/stories/mercury-guide, last accessed March 15, 2021.
“Fish,” Washington State Department of Health; https://www.doh.wa.gov/CommunityandEnvironment/Food/Fish, last accessed March 15, 2021.
“Fish: Friend or Foe?” Harvard T.H. Chan School of Public Health; https://www.hsph.harvard.edu/nutritionsource/fish/, last accessed March 15, 2021.
“Fish, salmon, Atlantic, wild, raw,” SELF Nutrition Data; https://nutritiondata.self.com/facts/finfish-and-shellfish-products/4102/2, last accessed March 15, 2021.
Leech, J., “Wild vs Farmed Salmon: Which Type of Salmon Is Healthier?” Healthline, November 8, 2018; https://www.healthline.com/nutrition/wild-vs-farmed-salmon, last accessed March 15, 2021.
“Fish, anchovy, European, raw,” SELF Nutrition Data; https://nutritiondata.self.com/facts/finfish-and-shellfish-products/4027/2, last accessed March 15, 2021.
“Health Benefits of Anchovies,” WebMD; https://www.webmd.com/diet/health-benefits-anchovies, last accessed March 15, 2021.
Kandola, A., “What to know about cod,” Medical News Today, March 18, 2019; https://www.medicalnewstoday.com/articles/324741, last accessed March 15, 2021.
“Fish, cod, Atlantic, raw,” SELF Nutrition Data; https://nutritiondata.self.com/facts/finfish-and-shellfish-products/4041/2, last accessed March 15, 2021.
“Canned Sardines: Are They Good for You?” WebMD; https://www.webmd.com/diet/canned-sardines-good-for-you, last accessed March 15, 2021.
“Fish, herring, Atlantic, raw,” SELF Nutrition Data; https://nutritiondata.self.com/facts/finfish-and-shellfish-products/4065/2, last accessed March 15, 2021.
“Fish, haddock, raw,” SELF Nutrition Data; https://nutritiondata.self.com/facts/finfish-and-shellfish-products/4059/2, last accessed March 15, 2021.
Gunnars, K., “How to Optimize Your Omega-6 to Omega-3 Ratio, Healthline, June 11, 2018; https://www.healthline.com/nutrition/optimize-omega-6-omega-3-ratio, last accessed March 15, 2021.