Most people think that fruits and vegetables washed on the good, eat or not to eat the skin is just a matter of taste, not related to health. But it turns out that this idea is very wrong, some fruits and vegetables if you eat with skin, or cooking skin is not clean, will give your body trouble. 1, persimmon skin Because persimmon skin taste good, people generally eat persimmons are not spit skin. However, according to medical research has proved that persimmons are not mature, can cause damage to the stomach and intestines of tannic acid mainly exists in the persimmon meat, and persimmons mature, tannic acid will be concentrated in the persimmon skin. 2, sweet potato skin Because sweet potato skin contains more alkali, too much consumption will lead to gastrointestinal discomfort. Brown or black spotted sweet potato skin can not be eaten, because this sweet potato is infected with black spot disease, consumption will cause poisoning. 3, potato peel Potato peel contains unhealthy with sugar alkaloids, into the body will form an accumulative poisoning. Because of chronic poisoning, there are no symptoms or symptoms are not obvious temporarily, often do not attract attention. In particular, potatoes with long sprouts and greenish skins contain higher toxins and should be absolutely prohibited from consumption. 4, water chestnut skin Because water chestnut is born in fertile water, the skin gathers a variety of harmful and toxic biological excretions and chemicals. Therefore, raw or cooked food should be peeled, otherwise it can cause unpredictable diseases.