Even delicious fish can carry hidden health risks from mercury, pollutants, or poor farming practices. Three widely eaten types are worth limiting or avoiding. King mackerel is heavily contaminated with mercury because it is a large, long-living predator. The FDA advises young children and pregnant or nursing women to avoid it completely. Swordfish also accumulates very high mercury levels, which can harm your cardiovascular and nervous system over time. If you do eat it, limit to once a month and consider safer alternatives like wild mahi-mahi.

Imported farmed catfish, often sold as basa or swai, poses a different risk. These fish are frequently raised in polluted, overcrowded pens and treated with antibiotics and banned chemicals that can remain in their bodies. When ordering catfish at restaurants, be cautious. Choosing domestic U.S. farmed catfish or other low-mercury options helps you avoid antibiotic residues and poor farming standards.

Smaller, shorter-lived fish like salmon, sardines, and trout tend to have much lower mercury levels. Wild-caught varieties are generally safer than imported farmed types. Rotating your fish choices and paying attention to sourcing can reduce your exposure to toxins while still allowing you to enjoy seafood.

Being informed doesn’t mean giving up fish entirely. It simply means making smarter choices. Limiting high-risk fish and opting for safer alternatives protects your long-term health without sacrificing taste or variety.