All the good ingredients are in the skin… Eat sweet potatoes and onions like this.

Reporter Kim Seo-hee's story

When cooking, we tend to discard the peels of fruits and vegetables. However, some foods surprisingly contain several times more nutrients in their peels. Let's learn about fruits and vegetables that are healthier when eaten with their peels.

◇Sweet potatoes

The anthocyanin in sweet potato skins helps remove free radicals from the body. Sweet potato skins are also rich in beta-carotene, which, when absorbed by the body, converts to vitamin A, helping prevent aging and boost immunity. Sweet potato skins are also rich in dietary fiber, which helps smooth bowel movements. Even when steamed or boiled, sweet potatoes retain vitamin C in their starch, so eating them with the skin enhances their health benefits. If you don't like the skin to be tough, chop it into small pieces and eat it in a salad. If you plan to eat sweet potatoes with their skins, be sure to thoroughly wash them of any dirt or foreign matter. This can be done by gently rubbing the sweet potatoes with a soft sponge or your hands under running water.

◇Danhobak

The peel of a sweet pumpkin is rich in antioxidants and phenolic acids, which the flesh lacks. Phenolic acids are effective in preventing aging, promoting blood circulation, and preventing cardiovascular disease. Therefore, it's best to steam and eat sweet pumpkin with the peel, or collect it separately, dry it for 3-4 days, and then brew it into tea. The seeds of a sweet pumpkin are also nutritious, not just the peel. Pumpkin seeds contain calcium and magnesium, making them beneficial for growing children and the elderly, who need to strengthen their bones, nerves, and muscles. It's recommended to wash and dry pumpkin seeds thoroughly before eating them.

◇Onion

Onion skins contain 30 to 40 times more flavonoids, an antioxidant, than the flesh itself. Flavonoids reduce vascular inflammation and eliminate free radicals that cause cell aging, preventing dementia and Parkinson's disease. Quercetin, another antioxidant, lowers blood cholesterol levels and cleanses blood vessels. Because onion skins are difficult to eat raw, you can brew them in water to make a broth, or dry them and eat them as a powder.

◇Apple

Anthocyanins, which give apple peels their red color, are rich in antioxidants that protect the body from enzyme activity and have the effect of strengthening lung function. Pectin, a dietary fiber found in apple peels, helps prevent constipation by promoting digestive activity. Apple peels also contain ursolic acid, which helps prevent obesity and regulate blood sugar levels. However, it's safer to eat apples after cutting off the stems, as they often contain pesticide residue.

◇Peanuts

Peanuts are rich in nutrients, both in their outer and inner skins. Peanut skins are rich in luteolin, which helps reduce brain inflammation and improve memory. Wash the outer skins thoroughly, steep them in boiling water, and drink as tea. The red inner skins of peanuts are rich in antioxidants, including catechins, which are effective in preventing diseases such as cancer. They are also rich in fiber, which provides a feeling of fullness and promotes bowel movement. If you find the inner skins too heavy for texture or other reasons, you can steam them or mix them with rice. According to the Rural Development Administration, rice cooked with peanuts (10% peanuts) has twice the antioxidant, protein, and mineral content of regular rice.