Not all fish are created equal, and some popular choices on restaurant menus may pose unexpected health risks.

Certain fish contain high levels of mercury, harmful toxins, or are raised in questionable farming conditions. Experts have flagged seven types in particular that you may want to avoid or consume sparingly.

Tilapia, for instance, is often promoted as a healthy option. However, its high omega-6 to omega-3 ratio may contribute to inflammation rather than reduce it, especially when consumed in excess.

Long-lived predatory fish such as swordfish, shark, and king mackerel accumulate mercury over time. Consuming too much of these fish can lead to mercury poisoning, which affects the nervous system, especially in children and pregnant women.

Farmed salmon is another concern. While it’s a good source of omega-3s, some farmed varieties are raised in overcrowded pens and may contain contaminants or antibiotics that carry health risks.

Imported catfish, especially those from countries with weak food safety regulations, can also carry pollutants and banned substances.

Orange roughy, a deep-sea fish with a long lifespan, tends to accumulate high levels of mercury and other toxins.

To make safer choices, opt for wild-caught salmon, sardines, trout, or mackerel, which tend to have lower toxin levels and higher nutritional benefits.

Understanding where your fish comes from and how it’s raised is essential to maintaining a healthy diet. Being informed helps you enjoy the benefits of seafood without the hidden dangers.