Are All Fish Healthy to Eat?

Scripps cardiologist recommends fish low in mercury

Scripps cardiologist recommends fish low in mercury

Doctors long have championed the heart health benefits of eating fish. They’ve also been careful recommending that you eat the right kinds of fish.


In brief, be wary of fish high in mercury, especially methylmercury, which is the most toxic mercury compound. If you’re on a fish diet or just like to eat it a lot, make certain it’s low in mercury.


“People should continue to eat fish because it’s a good lean source of protein and omega-3 fatty acids, which are good for your heart. Unlike fatty meat products, fish and shellfish are not high in saturated fat,” says Poulina Uddin, MD, a cardiologist at the Scripps Women's Heart Center. “However, seafood consumers should be cautious about what types they eat.”

Mercury in fish

Mercury is a heavy metal contaminant often linked to industrial pollution that makes its way into lakes, rivers and oceans and into the food chain. Fish high on the food chain, such as shark and swordfish, have higher concentrations of mercury than others.


For decades, mercury poisoning has been associated mainly with the central nervous system. Most mercury-related health warnings have been directed at women who are or plan to become pregnant, breastfeeding mothers and young children.


While some studies have linked mercury contamination to increasing the risk of heart disease, the American Heart Association (AHA) does not agree with those findings and remains confident in the heart health benefits of eating fish.The heart organization says “the benefits of eating fish substantially outweigh any risks associated with mercury contamination.“

What fish are healthy to eat?

The U.S. Food and Drug Administration (FDA) and the Environmental Protection Agency have declared that eating fish is part of a healthy eating pattern, including for women who are or may become pregnant, breastfeeding mothers and small children. Both recommend eating a variety of fish that are low in mercury, and have put together a list of the “best choices,” “good choices” and “choices to avoid” based on their mercury levels.

Choices to avoid

Fish high in mercury to avoid are: king mackerel, marlin, orange roughy, shark, swordfish, tilefish from the Gulf of Mexico and big eye tuna.

Heart healthy fish to eat

Good choices include tuna, Spanish mackerel, tilefish from the Atlantic Ocean, tuna, albacore/white tuna, canned and fresh/frozen tuna.


Best choices include anchovy, Atlantic mackerel, trout, catfish, clam, crab, crawfish, lobster, oyster, pollock, salmon, sardines, scallop, shrimp, canned light tuna and tilapia.


AHA recommends eating 2 servings of fish (particularly fatty fish such as salmon) per week. A serving is 3.5 ounce cooked, or about ¾ cup of flaked fish.


Dr. Uddin says walnuts and canola oil are also significant sources of omega-3 fats — without the risk of methylmercury.


“Patients concerned about eating a heart-healthy diet should consult their physician or a licensed dietitian.“