Catfish
While catfish is abundant in Vietnam and even exported abroad, tests for mercury and malachite green in the US have yielded positive results. As a result, catfish from Vietnam is considered a “dirty” fish and is best avoided.
Pufferfish
Pufferfish is dangerous for everyone as it contains mercury and deadly toxins. It is especially harmful to pregnant women and can be fatal if not prepared correctly. Pufferfish ovaries contain tetradotoxin, and the liver contains hepatoxin, which can be deadly.

Types of Fish to Avoid
Swordfish
Swordfish is a marine fish with high mercury levels. Excessive consumption can lead to methylmercury poisoning, so it’s best to limit your intake of this fish.
Bluefin Tuna
Bluefin tuna is often farmed and fed industrial food to increase its size. However, this results in higher calorie and saturated fat content and lower mineral levels. It also has lower omega-3 and omega-6 ratios than wild-caught tuna. Additionally, due to their habitat in deep seas with heavy metals, bluefin tuna may contain high mercury levels.

Types of Fish to Consume in Moderation
Safe Preparation Methods
– Always thoroughly cook seafood, including shrimp, fish, and oysters, to eliminate toxins.
– Purchase fresh food and store it in the refrigerator if not consuming immediately.
– Avoid raw fish dishes like sushi to minimize the risk of bacterial infections.
– Pregnant women should follow their doctor’s advice on fish consumption and not exceed the recommended amounts.
The 5 Dirtiest Fish at the Market: Filled with Parasites, Not Even Worth the Bargain
Fish is an indispensable food for humans, offering a plethora of health benefits. However, it is important to be aware of the potential dangers lurking in traditional markets. Recent studies by scientists have revealed that five types of fish are commonly found to be the dirtiest, laden with heavy metals and parasites, even shunned by the sellers themselves.
The Ancient Wisdom: “Don’t Buy Catfish” – But Today, a Delicacy?
The mudfish was once considered a cheap and undesirable fish, fit only for the poor. However, today it is a sought-after delicacy, prized for its unique flavor and texture. This humble fish has undergone a remarkable transformation, from a lowly and overlooked catch to a culinary favorite, gracing the tables of discerning food lovers across the land.