The fairness of skin mainly depends on the ability of melanocytes to synthesize melanin. In the basal layer of the human epidermis, melanocytes are distributed between cells. The tyrosinase they contain can oxidize tyrosine into polysaccharides, which then undergo a series of metabolic processes to finally produce melanin. The more melanin is produced, the darker the skin; conversely, the whiter the skin.
Which foods can darken the skin?
Studies have shown that the activity of tyrosinase is closely related to elements in the body such as copper, iron, and zinc. Regularly consuming foods rich in tyrosine and trace elements such as zinc, copper, and iron—for example, animal organs like liver and kidney; shellfish such as clams, crabs, river snails, and oysters; aquatic products like mullet roe; legumes such as soybeans, lentils, green beans, and red beans; nuts such as peanuts, walnuts, and black sesame; and raisins—can result in darker skin color. Therefore, people living by the sea, such as fishermen, have darker skin because they consume more of these aquatic products.