Fish is a delicacy that many people enjoy, but if not processed properly, it can lead to many diseases for humans.
When fish is fried until burnt, it produces more benzopyrene, a strong carcinogenic substance whose toxicity exceeds aflatoxin. Additionally, fish is rich in protein. If the fish is burnt, high-molecular-weight proteins break down into low-molecular-weight amino acids and can form mutagenic chemicals.
The consumption of salted fish has a certain correlation with the occurrence of nasopharyngeal cancer, a fact long confirmed by scientists. Research indicates that eating salted fish in childhood is more carcinogenic than doing so in adulthood. The reason salted fish can cause nasopharyngeal cancer is that during the pickling process, some proteins in the fish break down to produce secondary amines. Animal experiments have also shown that rats fed salted fish develop cancer, while the control group that did not eat salted fish showed no cancerous changes.
Fish contains unsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Although these fatty acids can lower blood cholesterol levels and prevent cardiovascular and cerebrovascular diseases, they can also be oxidized into harmful substances—lipid peroxides—which can damage human health and accelerate the aging process. Vitamin E can inhibit peroxidation reactions, thereby reducing the formation of lipid peroxides. Therefore, frequent consumption of fish increases the consumption of vitamin E, and failing to replenish it in a timely manner may affect health. Vitamin E can be supplemented through diet by consuming more corn oil, soybean oil, eggs, etc., or by taking oral vitamin E capsules.[美食中国]
The EPA in fish fat is metabolized into prostacyclin, which has lipid-lowering, blood viscosity-reducing, and platelet aggregation-inhibiting effects, and can prevent cardiovascular diseases. However, for patients with cirrhosis, this is harmful. Because in cirrhosis, the body has difficulty producing clotting factors, and with a reduced platelet count, bleeding is very likely. If they then consume fish rich in EPA, such as sardines, mackerel, and tuna, the condition can worsen dramatically, like adding insult to injury. Therefore, patients with cirrhosis should avoid these fish, but can consume small amounts of fish with lower EPA content, such as carp and flounder.
Fish also contains purine substances. Gout is caused by a disorder in the body's purine metabolism, mainly manifested by excessively high levels of uric acid in the blood, which can lead to a series of symptoms in the joints, connective tissues, kidneys, and other parts of the body. People with gout will experience aggravated symptoms if they eat fish.
Therefore, if you suffer from bleeding disorders such as thrombocytopenia, hemophilia, or vitamin E deficiency, it is better to eat less fish or avoid it altogether.