Hair color is determined by melanin production, which can shift during puberty due to hormonal and genetic factors.
Key facts
- •Hair color is determined by the balance of eumelanin and pheomelanin produced by melanocytes.
- •Higher levels of eumelanin result in darker hair shades.
- •The most noticeable hair darkening typically occurs during puberty, between ages 10 and 13.
- •Scientists have not yet identified the specific genes responsible for the darkening of blond hair.
- •Hormonal changes during puberty, including increases in estrogens and androgens, are suspected to influence pigment production.
Many children who are born with blond hair experience a gradual darkening of their locks as they grow. While the exact biological mechanisms remain under investigation, scientists attribute this change to a complex interaction between genetic inheritance and hormonal shifts that occur during puberty.
The Role of Melanin and Genetics
Hair color is produced by melanin, a pigment created by specialized cells called melanocytes within hair follicles. There are two primary types of melanin: eumelanin, which creates brown and black shades, and pheomelanin, which produces yellow and red tones. The specific color of a person's hair is largely determined by the amount and type of melanin their follicles produce. According to Desmond Tobin, a professor of dermatological science at University College Dublin, whether a child's hair remains blond or darkens is primarily dependent on their genetic inheritance.
Hormonal Changes During Puberty
For many children, the most significant darkening of hair occurs between the ages of 10 and 13. Researchers believe that hormonal changes during puberty, such as increases in estrogens and androgens, may stimulate the production of eumelanin. Wojciech Branicki, a researcher at Jagiellonian University, suggests that hormones might influence hair follicles differently based on a child's genetic background, leading some follicles to ramp up pigment production while others continue to produce lower levels of eumelanin.
Ongoing Scientific Research
While the melanocortin system—which includes hormones like alpha-melanocyte-stimulating hormone—is known to signal pigment cells to produce more melanin, scientists have not yet confirmed that this system is responsible for the darkening of blond hair. Researchers have not identified the specific genes that control this process, and the precise way hormones interact with hair follicles to cause color changes remains a subject of ongoing study.
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This article was independently rewritten by ManyPress editorial AI from reporting originally published by Live Science.
