White sugar: white sugar is often parasitized by mites, and eating white sugar raw is easy to get acariasis. Mite is a small insect with long hair all over the body, which is invisible to the naked eye. Mite breeds quickly in sugar. If mites enter the gastrointestinal tract, it will cause abdominal pain, diarrhea and ulcer. If it enters the lungs, it will cause hemoptysis and asthma. If it enters the urethra, it can cause urinary tract inflammation. Therefore, it is best not to eat white sugar raw, and it should be heated before eating.

Honey: when bees brew honey, they often collect some toxic pollen. After these toxic pollen are brewed into honey, people are prone to poisoning when they eat raw honey. In addition, honey is easily contaminated by bacteria in the process of harvesting, transportation and storage. Therefore, raw honey is inedible.

Fresh Auricularia auricula: It contains light-sensitive substances in leafy forests. After eating fresh Auricularia auricula raw, it can cause solar dermatitis, and in severe cases, skin itching, edema and pain occur.

Raw egg: The anti-biotic protein contained in egg white will hinder the absorption of biotin after binding with biotin in the intestine. Raw eggs often contain salmonella, which can cause vomiting and diarrhea.

Almond: It contains cyanoside, which is a highly toxic chemical substance. It is poisonous when eaten raw and volatile when exposed to water. Therefore, bitter almonds are soaked in water, the seed coat is removed, and then soaked in water for several days, and the water is often changed until the bitterness is removed before eating.

Day lily: It contains colchicine, which is also a highly toxic chemical. Eating 3-20 mg can kill people, so it must be boiled before eating.