You can't eat it raw. Wild vegetables such as shepherd's purse and grey vegetables in green vegetables all contain a lot of nitrite. If the human body ingests too much nitrite, the normal hemoglobin in the human body can be oxidized to methemoglobin. In addition, nitrite can also prevent oxygenated hemoglobin from releasing oxygen, thus causing tissue hypoxia and poisoning. Wild vegetables such as shepherd's purse and grey vegetables in green vegetables all contain a lot of nitrite. If the human body ingests too much nitrite, the normal hemoglobin in the human body can be oxidized to methemoglobin. In addition, nitrite can also prevent oxygenated hemoglobin from releasing oxygen, thus causing tissue hypoxia and poisoning.