What foods are unpalatable and nutritious, but still sought after by people? Why?

shark fin? Shark's fin, the filamentary cartilage in shark's fin, like bird's nest, is a "nourishing product" that is only respected in the Chinese world. In fact, the taste of shark's fin is very general, and the delicacy depends on condiments. More importantly, the nutrition of shark's fin is not as good as that of eggs and milk. At present, there is no exact scientific basis to prove that eating shark's fin is beneficial to health. In addition, there are many terrible inside stories behind shark fin. ? Let's look at the main components of shark's fin. Like bird's nest, the content of protein in shark's fin is really high. The shark's fin contains about 8% protein, fat, sugar and other minerals, and most of them are collagen. Seeing this information, many people think that this shark's fin must be nutritious, which can not only beautify the face, but also nourish the body. However, a lot of protein in shark fin is not the high-quality protein needed by human body, and collagen can't be nourished on our skin.