Generally, leafy vegetables have higher nutritional value than gourd vegetables. For the same vegetable, the vitamin content in the leaves is generally higher than in the roots and stems. For example, the deep green leaves of lettuce, celery, and radish tops are several times higher in nutrients than their corresponding roots and stems. This is because leaves are the part of the plant where photosynthesis occurs, so their nutrient density is generally higher than other parts. They are rich in many health-promoting components such as vitamin C, vitamin B2, folate, vitamin K, carotenoids, and flavonoids. They also contain dietary fiber, potassium, magnesium, calcium, and other nutrients.
Lettuce Leaves: Besides water content, which is similar to the stem, the three energy-yielding nutrients (protein, fat, and carbohydrates), as well as inorganic salts and elements like sodium, calcium, iron, manganese, zinc, copper, and selenium, are all higher in the leaves than in the stem. The content of vitamins B1, B2, C, and E in lettuce leaves is 3 to 5 times higher than in the stem. Especially, the carotene in the leaves is almost 10 times that of the stem. Additionally, the chlorophore rich in lettuce leaves, known as the "green elf," has the effects of moisturizing the skin, beautifying, cleaning the mouth, preventing cavities, and removing bad breath.
Celery Leaves: The content of protein, fat, carbohydrates, dietary fiber, various vitamins, and elements such as manganese, zinc, copper, phosphorus, and selenium are all higher in the leaves than in the stem. The advantage of celery leaves lies in their carotene and vitamin E content. The former is second only to carrots and kale, while the latter is slightly inferior to cowpeas, daylilies, and wolfberry leaves, ranking among the top in vegetables.
Radish Tops: The protein content in radish tops is not only higher than in radishes but also exceeds that of Chinese cabbage, bok choy, celery, lettuce, lotus root, and many gourd vegetables. Moreover, the content of carotene, vitamin C, and calcium is not inferior to that of radishes. Especially for the trace element manganese, the content in radish tops is almost 7 times higher than in radishes, and it also has high medicinal value.