Green beans (also known as kidney beans, lima beans, sword beans, runner beans, hyacinth beans, etc.) are a vegetable commonly consumed throughout the year. Poisoning from green beans can occur at any time of the year, but it is more frequent before and after the first frost. The main cause of such poisoning is related to the cooking method. For instance, using them as a filling (for dumplings or buns), blanching them in boiling water for noodle soup, stir-frying them over high heat, or preparing them in various cold salads with blanching. The poisoning is caused by incomplete cooking during preparation, which fails to destroy the toxic components. All green beans that cause poisoning share a common characteristic: "the beans have not changed color completely, and they taste raw and have a strong, beany flavor when chewed."
Why do green beans cause poisoning? This is because they contain a toxic substance called lectin. It is currently believed that this lectin can cause red blood cells to agglutinate (clump together) and also has a hemolytic effect, meaning it can destroy red blood cells. Eating them raw or not fully cooked can lead to diarrhea and hemorrhagic enteritis.
After consuming toxic green beans, symptoms usually appear within 1 to 5 hours. The main symptoms include nausea, vomiting, abdominal pain, diarrhea, dizziness, and headache. In a few cases, patients may experience chest tightness, palpitations, cold sweats, numbness in the limbs, cold hands and feet, and a feeling of chills. Individuals who exhibit these poisoning symptoms should seek timely medical attention and treatment.
To prevent green bean poisoning, the general public is reminded that when cooking green beans, it is best to stew them thoroughly to ensure they are fully cooked. This will destroy the toxins and help prevent green bean poisoning.