It is often said that eating soy sauce and drinking coffee will make the skin darker, and you can’t eat soy sauce if you have injuries on your body, otherwise you will be left with unsightly scars. In fact, these claims are not based on science. Medical research has found that human skin color is related to the melanin content in the human body and racial genetics, and has nothing to do with the color of food in the diet. The amount of melanin is mainly regulated by endocrine and also increases due to ultraviolet radiation in the sun. If the sunlight exposure time is longer in summer, the skin color will become darker, and in winter the sunlight exposure time is shorter, the skin color will become lighter, so there is the phenomenon of dark skin in summer and white skin in winter. The secretion of female physiological period such as estrogen, progesterone, etc. can also promote the synthesis of melanin. In addition, people who eat more food that is extremely light sensitive, such as celery and mangoes, are prone to spots or yellowing by sunlight exposure. The color of the skin is mainly determined by melanin, in addition to racial inheritance. If you have more melanin, your skin will be darker and vice versa. There are many factors that can lead to pigmentation, such as sunlight and ultraviolet radiation can make the skin darker; female physiological secretion such as estrogen and progesterone can also promote the synthesis of melanin. In addition, people who eat more food that is highly susceptible to light such as celery, mango, etc., are prone to spots or yellowing by sunlight exposure. Most of the soy sauce on the market is made from soybeans and wheat, which is the same as other foods and can be absorbed by the body after digestion, such as amino acids, carbohydrates, inorganic salts and water. It does not work. Whether or not a skin injury will produce a scar depends largely on the extent of the skin injury and whether or not it is secondary to a bacterial infection. If only the epidermis or even the superficial layer of the dermis is injured, no scar will be left as long as no secondary infection occurs; if the deeper dermis is injured, scarring will inevitably occur. Does eating soy sauce really cause pigmentation and darkening? This problem must have been understood by the reader, now do not have to be afraid of it! Soy sauce can still be eaten with confidence.