Preserved eggs contain lead. If eaten regularly, it may cause lead poisoning. This can lead to symptoms such as insomnia, inability to concentrate, anemia, joint pain, slow thinking, and affected brain function.

The lead content of preserved eggs produced by traditional techniques is high because lead oxide is used in the production process. This substance has a sealing effect and can block the small holes on the surface of preserved eggs. , thereby preventing the strong base from further chemical reaction with the protein.

With the advancement of technology, after 2008, the country issued new standards for preserved eggs, stipulating the lead content. Nowadays, regular manufacturers have begun to use "lead-free technology" to make preserved eggs, that is, using zinc chloride or copper sulfate instead of lead oxide, which can not only reduce the lead content, but also seal the holes.

Preserved eggs are not suitable for people

Weak and sick people.

Preserved eggs are easily contaminated by E. coli, salmonella, etc. The weak and sick people have poor resistance and are easily infected by bacteria, which can induce various intestinal diseases. Sensitive people may suffer from symptoms of food poisoning. Moreover, preserved eggs are cold in nature, and those with weak spleen and stomach may easily cause diarrhea after eating them. It is recommended that the weak and sick people eat less or not eat at all. .

People with liver disease.

The liver is the body’s detoxification organ, but it cannot catabolize heavy metals. Patients with liver disease who eat too much preserved eggs may cause heavy metal poisoning and affect the nervous system and digestive system. In addition, preserved eggs are rich in protein, which will produce a large amount of amino acids after decomposition. If patients with liver disease eat too much at one time, it may cause ammonia poisoning and hepatic coma, and in severe cases, death.

People with high blood pressure.

The sodium content of preserved eggs is higher, five times that of ordinary eggs, and the cholesterol content is no different from ordinary eggs. Patients with high blood pressure should eat as little as possible.

References for the above content? People's Daily Online - Five categories of people should be careful about eating preserved eggs, People's Daily - Are preserved eggs safe or not, Baidu Encyclopedia - Preserved eggs