If you want to turn gray hair into black hair, dietary intake is very important, and some patients are caused by the lack of certain elements. First of all, patients are advised to eat more black sesame seeds, which are rich in lecithin and vitamin E. These nutrients can promote the formation of black hair. Secondly, you can also eat more walnuts, walnuts have a brain tonic effect, because they contain a lot of vitamins, which promote the formation of black hair. Once again, you can also eat more taro, which is rich in protein, phosphorus and carotene, which is a good product for hair growth. In addition, patients can also intake foods containing more trace elements, such as carrots, wolfberries, black beans, purple cabbage and other foods, the generation of gray hair and bad brain habits have a certain relationship, it is recommended to relax.