While larger fish are often associated with higher quality and nutritional value, with some consumers willing to pay a premium for them, it’s important to be aware of potential risks associated with consuming certain types of large freshwater fish.
Large Freshwater Fish: Delicious or Dangerous?
Most freshwater fish weighing between 1.5 and 2 kg have already required several years of careful farming and husbandry. While fish weighing 4-7 kg may be advertised attractively, caution is warranted. Such fish may:
Be injected with growth hormones: To achieve their large size, farmers may have used growth stimulants over extended periods, leading to toxin accumulation in the fish’s body.
Have lived in polluted environments: Older fish from muddy areas may have absorbed harmful substances from their surroundings, posing health risks to consumers.
Consuming these fish may not only lack nutritional benefits but also introduce toxins into your body, leading to potential health hazards.
Signs of Unsafe Fish
Distended Belly
If a fish is motionless and has an abnormally distended belly, it’s likely been dead for a while. Decomposition of its internal organs generates gas, causing the belly to bloat. Post-mortem, bacteria proliferate rapidly, producing foul-smelling organic acids that alter the fish’s color and nutritional composition. Decomposing flesh also produces toxins, which can lead to:
Acute food poisoning: Manifested through digestive disorders, bloating, abdominal pain, and diarrhea.
Long-term consequences: Accumulation of harmful chemicals in the body, damaging the liver, kidneys, lungs, and nervous system.
Tuna
Tuna has a high mercury content and can cause poisoning if consumed frequently. For health reasons, it is advisable to limit your intake of this fish to reduce the risk of chronic illnesses.
Clown Knife Fish and Mangrove Jack
Despite their popularity in Vietnam and being exported, Clown Knife Fish and Mangrove Jack have been found to contain mercury and the toxic chemical, malachite green, during inspections in the US. They are categorized as “dirty fish” and should be avoided.
Puffer Fish
Puffer fish are extremely dangerous due to the presence of tetrodotoxin in their ovaries and hepatotoxin in their liver. Improper preparation of puffer fish can lead to fatal poisoning. Pregnant women should refrain from consuming this fish altogether.
Swordfish
Swordfish is a marine species with high mercury levels. Excessive consumption can result in methylmercury poisoning, adversely affecting your health.
