The tender, fragrant white fish has just been served, and its fresh aroma makes everyone eager to take a bite. It’s often said that eating fish makes you smarter and healthier—but did you know that some types of fish can pose health risks, even introducing toxins into your body if not consumed properly? In particular, these three common market fish, no matter how cheap, should be consumed with caution.

3 Types of Fish to Watch Out For

1. Large carnivorous fish with high mercury levels
Fish like tuna and swordfish are top predators in the food chain, making them prone to accumulating heavy metals like mercury. Pregnant women and children should be especially careful, as mercury can affect neurological development. It’s best to limit consumption to no more than twice a month, with each serving under 100g.

2. Frozen ocean fish stored too long — risk of fat oxidation
Fish such as saury and mackerel that have been frozen for extended periods or show yellow discoloration in the freezer should raise concern. If defrosted multiple times or stored for over six months, the fats in the fish can oxidize, creating a rancid (oily, unpleasant) odor. If the fish smells strange after cooking, throw it away—don’t risk it!

3. Freshwater fish of unknown origin — risk of parasites
Fish like tilapia, catfish, eel, or snakehead caught in the wild may carry liver flukes. Undercooked fish poses serious risks. Avoid dishes like raw fish salad or lightly cooked fish porridge. When buying, choose reputable sellers—check that the fish’s eyes are clear and its gills are bright red.

---

4 Rules for Eating Fish Safely

• Choose the right type: Medium-sized sea fish like pomfret or mackerel are generally safer. For freshwater fish, choose those farmed under well-controlled conditions. Eating fish 2–3 times per week, each serving about the size of your palm, is sufficient.

• Cook properly: Steaming or boiling helps retain nutrients. Avoid deep-frying at high heat (above 180°C). If grilling, wrap the fish in foil to minimize the formation of cancer-causing substances.

• Remove toxin-prone parts: Discard the fish’s head, guts, and skin if safety is uncertain. Especially remove the dark membrane in the belly, where toxins are most likely to accumulate.

• Pair foods wisely: Pair fish with tofu or radish to aid nutrient absorption. Avoid combining with persimmon or hawthorn, which may cause digestive issues.

---

Who Should Be Extra Cautious

• People with gout: Should limit fish, especially during flare-ups.

• Those prone to allergies: Try a small amount first when eating unfamiliar fish.

• Those on antibiotics: Consult a doctor before consuming fish.

---

Tips for Choosing Fresh Fish: Look for These 3 Signs

• Eyes: Clear, slightly bulging, not cloudy.

• Gills: Bright red, no strange odor.

• Flesh: Firm, bounces back when pressed.

Note: Fish that appear too shiny or unusually glossy may have been chemically treated. The freshest fish isn’t always the prettiest.

---

Fish is a nutritious food, but not all kinds should be eaten carelessly. Don’t let low prices or convenience blind you to potential health risks.