Most people think that it is good to wash the fruits and vegetables. Eating or not eating the skin is just a matter of taste and has nothing to do with health. As it turns out, this idea is all wet. If some fruits and vegetables are eaten with skin attached, or the skin is not cleaned when cooking, it will cause trouble to your body ...1.Persimmon skin has a good taste, so most people don't spit it when eating persimmons. However, according to medical research, tannic acid, which can cause harm to the stomach and intestines, mainly exists in the flesh of persimmon when it is immature, while tannic acid will concentrate in the skin of persimmon when it is ripe. 2. Sweet potato skin Because sweet potato skin contains more alkali, eating too much will lead to gastrointestinal discomfort. Brown or black spotted sweet potato skin is even more inedible, because this sweet potato is infected by black spot disease, which will cause poisoning after eating. 3. Potato skin Potato skin contains glycoalkaloids that are not conducive to human health, and will form cumulative poisoning after entering the human body. Because it is chronic poisoning, temporarily asymptomatic or the symptoms are not obvious, it often does not attract attention. In particular, potatoes with buds and blue skin contain more toxins and should be absolutely forbidden to eat. 4. Water chestnut skin is born in fertile Shui Ze, and there are many harmful and toxic biological excreta and chemicals on the skin. Therefore, raw food or cooked food should be peeled, otherwise it will cause unpredictable diseases.