What is the Best Low Mercury Fish?

If you eat seafood, you’re probably mindful of the mercury content in fish. I know it’s confusing to figure out what type of fish will actually provide you with the highest nutrient density (protein + omega-3s), so I’ve done some digging for you to help you make more informed choices. Most of us get more omega-6s than omega-3s through our regular diet. Though both are helpful, you’ll want the omega-6 to omega-3 ratio to be: 2:1 to 4:1. For most of us, this means that we need to increase the amount of omega3-s in our diet to take advantage of the anti-inflammatory, heart health, brain health, and hormone health protective benefits that omega-3s provide us with. In Western diets, the omega-6 intake is often too high, which can lead to chronic inflammation. This is where low mercury fish comes in!

Of course, the best low mercury fish is not always the most affordable, so I’ve included budget-friendly options in this list as well. We’ll be comparing seafood based on nutrient density, protein content (spoiler alert: all except one of these are great sources of protein), mercury levels, and omega-3 content. You probably already know that salmon is the king of omega-3s and anti-inflammatory protein, but you’ll want to read all the way to the end to find out what types are going to be better for you to consume. Let’s start with the worst fish, in terms of nutrient density:

1. Tilapia – Although it’s low in mercury, it’s very high in toxins unless you purchase this wild-caught. Most tilapia on the market today is farmed and raised in unsanitary conditions. Many farms also use antibiotics and pesticides to combat diseases, which means you may be eating chemical residue along with your tilapia. Tilapia may be inexpensive and is a good source of protein, but contains low omega-3 levels compared to many other fish. It also has a higher omega-6 to omega-3 ratio, which can lead to inflammation in the body. In general, I would advise against purchasing tilapia. If you’re going to get some, pay attention to the origin of the tilapia and stick to responsibly farmed Tilapia from the US or Latin America.
2. Cod – Another low mercury fish, a great source of protein, and mild tasting. This is your typical “fish and chips” fish. It’s versatile and easy to prepare, but only contains around 150mg of omega-3s per 100 grams of cooked fish, which is not very high. If you’re getting some cod, opt for wild-caught Atlantic cod instead of Pacific, for the same reasons as with Tilapia – farmed fish is going to be higher in contaminants, chemicals, pesticides, heavy metals, and antibiotics. Poorly regulated farms also overcrowd fish, which leads to more diseases, stress for the fish, and lower quality meat.
3. Haddock – Similar to cod, but less flaky and a bit more sweet. Another great source of protein that is usually available wild-caught. Around 150mg of omega-3s per 100 grams of cooked fish, so not very high either in terms of omega-3 nutritional content.
4. Shrimp – Even though shrimp is a bottom feeder, meaning that they live on the bottom of the ocean floor, doesn’t necessarily mean you need to avoid them. You’ll definitely want to purchase wild-caught Gulf shrimp, which is much better in quality compared to Asian imports, which are almost always farm-raised in unsanitary conditions. What I love about shrimp is that you can eat a handful for a huge amount of protein and calories and they are very low in mercury as well. You’re getting around 300mg of omega-3s per 100 grams of cooked shrimp, which is decent, but we can definitely do better on the omega-3s.
5. Yellowfin Tuna – You’ve probably been told to avoid this one because it’s high in mercury. I would definitely recommend limiting it if you’re pregnant. Otherwise, I wouldn’t consume this more than once or twice a week as you’re not getting many omega-3s in either. It is chockfull of protein and used mostly in sushi.
6. Bluefin Tuna – Same deal here, a high mercury fish, good omega-3s as well, but since it’s so rare, it’s also pricey and not the type of fish you’ll want to cook at home. I would stay away from Bluefin tuna because of the high mercury levels and sustainability issues.
7. Albacore Tuna – Another high mercury fish that is commonly canned. I don’t love cans because of the BPA lining in most cans and exposing fish to additional heavy metals from the can itself. But, the plus here is that canned fish can be a very cost effective option. Most brands out there will be untested for heavy metals, so I recommend sticking with brands such as Wild Planet and Safe Catch. Albacore tuna is a great option in terms of protein, but I would not consume it more than about once a week.
8. Sea Bass – High mercury, really great texture and buttery, which is why it’s often found at high-end restaurants.
9. Halibut – A more expensive fish, excellent protein again, but moderate mercury. Halibut would be worth getting for a fancy dinner and you’ll want to look for Pacific Halibut over Atlantic.
10. Swordfish – Higher omega-3s, but also the highest in terms of mercury, which is why you’ll want to limit swordfish to about once a month.
11. Sardines – SO amazing for their 1,500 mg per 100g of omega-3s! Sardines are also very low in mercury, but do come mostly canned. My preferred brands are Wild Plant and Season. Since sardines are so tiny, you can eat the bones, which are a great source of calcium.
12. Anchovies – Another favorite of mine (and my kids!), but most people tend not to like it because it’s so high in omega-3s and so low in mercury. You’ll find these jarred or canned and you’ll want to stick to Italian or Spanish anchovies.
13. Trout – Rainbow trout is another wonderful low-mercury, high omega-3s (about 900mg per 100g) fish that you’ll want to purchase either fresh or frozen.
14. Mackerel – An oily fish with a whopping 4,000 mg of omega-3s per 100g. It’s more commonly canned, unless you visit a fish market for a fresh cut. As a general rule, opt for Spanish mackerel over Atlantic mackerel since this fish does have a moderate amount of mercury.
15. Oysters – Similar to anchovies, a great source of omega-3s, but actually not a great source of protein. So, why do people eat oysters when they’re so weird? You get a ton of zinc, vitamin B12, copper, selenium, and iron – so a ton of vitamins and minerals for very few calories and mercury. Definitely an acquired taste, so don’t worry if you don’t like oysters – plenty of other nutrient dense options as well.

So, What’s The Deal with Salmon?

As you probably already know, salmon is an excellent source of omega-3s and protein. We try to eat salmon twice a week in our household and I made sure our boys were exposed to salmon pretty early on so that they could get used to the flavor and texture of it.  Most of the salmon you’ll find on the market today is Atlantic salmon. You’ll find huge Atlantic salmon fillets at Costco and….you’ll want want to stay away from these. Most Atlantic salmon is farmed salmon and fed a diet of corn, fishmeal, and soy – which all increase omega-6 levels, exactly the opposite of what you’re trying to do! Farmed salmon has higher levels of heavy metals and lower nutrient quality. As with most farmed fish, you’ll find higher pesticide use, more antibiotic resistance, pollution, chemicals, and diseases in farmed salmon. Wild-caught salmon is naturally orange in color, whereas farmed salmon is actually gray-ish white and given color additives to make their flesh look orange. Though not dangerous, some farmed salmon is given synthetic colors made from petrochemicals.

But then…why does it taste better than wild-caught salmon?! Sockeye salmon is the most common alternative to farmed salmon, but doesn’t taste as fatty. Farmed salmon will have higher levels of fat, which give it its rich, buttery flavor, but it actually contains less DHA and EPA (the most beneficial forms of omega-3) than wild-caught salmon. Disappointed by this, our family sought after the buttery flavor we love, without the disadvantages of farmed salmon. Here’s what we found: king salmon turns out to be the king of wild-caught salmon and is most similar to Atlantic salmon in flavor. We found ourselves finding king salmon at Alaska Home Pack and Wild Alaskan Company. Both are pricey, so if those aren’t an option for you, Costco’s Kirkland brand of canned wild-caught salmon is fantastic as well and excellent when used in salmon cakes. Overall, wild-caught salmon in my most recommended type of fish and as a holistic health coach, I would pick it over most other protein sources.

What seafood do you enjoy the most? Is it on this list?