Ranking Fish by How Healthy They Are

Sardines? Snapper? Shark? Which is least likely to fill me with plastic?

Fish is, in general, healthier than meat, since it contains more omega-3 fatty acids, which prevent heart disease, and less artery-clogging saturated fat. But among fish, which are the healthiest? I asked Dana Hunnes, senior dietitian at the Ronald Reagan UCLA Medical Center, to help me rank various fish — from superfood to super-full-of-plastic.

But first, Hunnes explains that smaller fish from deeper (colder) water typically contain higher amounts of omega-3 fatty acids and fewer dangerous microplastics. Hunnes also says that smaller fish usually contain less mercury, and therefore, eating them is less likely to result in you developing mercury poisoning. However, nutritionist David Friedman, author of Food Sanity: How to Eat in a World of Fads and Fiction, recently told us that the link between eating fish and developing mercury poisoning is massively overblown:

“It’s way over exaggerated and I debunk the ‘mercury fish farce’ in my book; however, if developing mercury toxicity is a concern, go for a ‘safe catch’ brand of tuna — their allowable limit for mercury is 10 times stricter than the FDA’s mercury limit.”

All of which means (1) we’ll let you decide whether you want to worry about mercury poisoning; and (2) that this ranking is mostly based on the amounts of omega-3 fatty acids, and especially those harmful microplastics, found in each fish. And because we care about the future of our fishy friends, we’ll also be considering overfishing practices.

I also want to point out that, despite their name, shellfish aren’t actually fish. In fact, many varieties of shellfish — particularly crustaceans, like lobsters and crabs — are actually closer related to insects and arachnids, so we’ll be devoting an entire ranking to those little sea-aliens in the near future.

With that, let’s go fishing…

1. Sardines, Herring and Mackerel (tied): “These are all relatively small deep-water fish with high levels of omega-3 fatty acids,” Hunnes says — because these small fish sit near the bottom of the food chain, they also rarely accumulate microplastics that are especially common in larger predatory fish. Hunnes also mentions that eating smaller fish is more environmentally sustainable, which is particularly important when you consider that overfishing may result in the complete eradication of all seafood by 2048.

4. Tilapia and Catfish (tied): Both tilapia and catfish usually have low microplastic and mercury contents, which is why the FDA recommends these fish as two of the best choices for pregnant women and young children. Hunnes does mention, however, that both fish contain only small amounts of omega-3 fatty acids, adding that the common practice of farming them can reduce their omega-3 fatty acid content depending on their feed. Fun fact: Tilapia isn’t even actually a fish — it’s a blanket term for nearly one hundred species of similar fish (my mind is officially blown).

6. Cod: First and foremost, Hunnes mentions that cod have a lengthy history of being subject to overfishing and being eaten before having a chance to reproduce. She adds that, much like tilapia and catfish, cod tend to be lower in omega-3 fatty acids; however, they also tend to be low in microplastics and other contaminants because they remain relatively small throughout their lifetimes.

7. Trout: Hunnes says that trout are much more overfished than the fish listed above and that farmed trout oftentimes develop diseases that they later spread to wild populations. For these reasons, farmed trout can sometimes be considered unsafe to eat. That said, wild-caught trout comes with a hefty serving of omega-3 fatty acids and B vitamins that help the body convert food into energy and prevent heart disease.

8. Salmon: Let’s be honest: You and I both expected salmon to be higher up on this list, because it’s loaded with omega-3 fatty acids, B vitamins and essential minerals (although, salmon admittedly contains more unhealthy saturated fat than many of the fish listed above). But even though salmon is somewhat of a superfood, Hunnes says that our farming practices have largely ruined this previously healthy fish. “When farmed, salmon isn’t safe to eat more than once a month and often harbors sea lice, which can infect wild populations,” she says, adding that, while wild-caught salmon is a healthier alternative, “they’re in major decline in the Pacific Northwest.”

9. Snapper: Snapper aren’t particularly high in omega-3 fatty acids, and Hunnes mentions that they’re on the verge of extinction due to overfishing. Put simply, contributing to the decline of these fish simply isn’t worth their lackluster nutritional content.

10. Yellowtail: Also known as amberjack, yellowtail are high in omega-3 fatty acids, but they oftentimes feed on wild fish — even while they’re being farmed — meaning they can accumulate high amounts of dangerous contaminants.

11. Halibut: Hunnes compares eating halibut (and every fish that follows) to “eating a grandmother fish, because they can live a long time and oftentimes contain high levels of mercury and plastic residue.” The oldest recorded halibut was 42 years old, and halibut can weigh up to 500-ish pounds. Halibut contains a hefty portion of omega-3 fatty acids in addition to an array of vitamins and minerals, but Hunnes argues that the dangers of eating such a large, potentially contaminated and overfished fish outweighs any possible health benefits.

12. Tuna: As Friedman explained during our ranking of sandwiches, tuna is pretty damn healthy:

“Tuna is a rich source of vitamin B12, vitamin B6 and niacin. Niacin metabolizes carbohydrates, proteins and fats into energy, while vitamin B6 and vitamin B12 remove the amino acid homocysteine from the bloodstream, which is beneficial because high levels of homocysteine are associated with an increased risk of cardiovascular disease. Tuna also gives us 80 percent of our daily recommended amount of selenium, which research shows may help prevent cancer. It’s also high in omega-3 fatty acids, which are important for heart health and brain function.”

Still, Hunnes says that tuna tends to be pretty high in contaminants, which can make it dangerous to eat on a regular basis. It’s especially important to keep track of where (and how) the tuna you eat ended up on your plate if you’re going to eat it.

13. Swordfish: Hunnes explains that swordfish are “terribly high” in mercury and plastic residue, because they basically eat every fish that gets in their way. For this reason, the FDA recommends not eating them.

14. Grouper: “These fish can grow to be between 50 and 100 years old,” Hunnes says, emphasizing that they tend to be chock-full of contaminants as a result.

15. Shark: While there are several species of shark that humans eat, Hunnes warns against consuming any of them, if only because they’re predatory fish filled to the brim with contaminants. Making matters even worse, shark finning is a brutal and all too common practice that results in many sharks being thrown back into the ocean after having their fins slices off — and because these sharks can no longer swim, they sink to the bottom of the sea, where they either die from suffocation or become fish food. “Nearly 100 million sharks are killed each year for their fins,” Hunnes says.

16. Fish Sticks: Predictable, but disappointing. Hunnes explains that fish sticks are usually made from whitefish, like cod, which can be pretty healthy — that is, until you drench them in oil. “The fried nature of fish sticks pretty much makes them unhealthy,” she says. That’s because fried foods absorb the calories and fats in the oil that they were fried in, both of which are bad for your waistline and heart.

More than anything, this ranking should emphasize the importance of understanding both where and how your seafood is caught, which can dramatically impact the health and sustainability of that meal. To keep track of that kinda stuff, we recommend checking out SeafoodWatch.org.