Some fruit and vegetable peels are rich in nutrients, such as those from tomatoes, pears, and apples, so many people eat them without peeling. However, there are four types of fruit and vegetable peels that are best not eaten.
1. Potato skins.
Potatoes contain glycoalkaloids, a toxic substance that is almost entirely concentrated in the potato peel, especially in the green and sprouted parts. Some people like to cook beef with potatoes on the skin, but the cooked peel still contains glycoalkaloids. Consuming large amounts can cause symptoms such as vomiting, dizziness, and diarrhea.
2. Persimmon skins.
The skin of ripe persimmons contains a large amount of tannic acid, which gives them a astringent taste. Under the action of stomach acid, tannic acid will combine with proteins in food to form a precipitate, known as a persimmon stone. This substance can easily cause symptoms such as upper abdominal discomfort, bloating, and loss of appetite. Therefore, do not eat unpeeled persimmons, and do not eat them on an empty stomach.
3. Sweet potato skins.
Sweet potatoes grow underground for a long time, and their peels are in direct contact with the soil, causing many harmful substances to be absorbed by the peel. Moreover, sweet potato peels contain a high amount of alkali, and excessive consumption can cause gastrointestinal discomfort. Additionally, many vendors selling roasted sweet potatoes on the street save costs by using coke as fuel, and harmful substances like sulfur dioxide can easily accumulate in the peel. Therefore, eating roasted sweet potatoes with the peel poses a cancer risk.
4. Water chestnut skins.
Water chestnuts grow in paddy fields, and their peels absorb many harmful and toxic biological waste products, and also contain parasites. Eating raw water chestnut peels can cause symptoms such as diarrhea and vomiting. Furthermore, it should be noted that water chestnut peels contain a high amount of starch, so diabetics should consume them with caution.