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有可能是基因的问题,吃啥都没治的
http://en.wikipedia.org/wiki/Hum ... aging_on_hair_color
Effects of aging on hair color
Children born with some hair colors may find it gradually darkens as they grow. Many blond, strawberry blond, light brown, or red haired infants experience this.
Changes in hair color typically occur naturally as people age, eventually turning the hair gray and then white. This is called achromotrichia. More than 40 percent of Americans have some gray hair by age 40, but white hairs can appear as early as childhood. The age at which graying begins seems almost entirely due to genetics. Sometimes people are born with gray hair because they inherit the trait.
Two genes appear to be responsible for the process of graying, Bcl2 and Bcl-w. The change in hair color occurs when melanin ceases to be produced in the hair root and new hairs grow in without pigment. The stem cells at the base of hair follicles produce melanocytes, the cells that produce and store pigment in hair and skin. The death of the melanocyte stem cells causes the onset of graying.[8] |
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