The answer is actually believed to be an interesting mixture of both. Gray hair is due to a loss of pigmentation. Hair pigments are composed of melanocytes, which are responsible for implanting melanin into the keratin-containing cells of our hair. A plausible explanation for gray hair could be due to deterioration of the melanocyte cells, resulting in less melanin in the hair proteins. Also, environmental factors such as stress and shock can increase graying hair, though this concept is still not completely understood.
But why do single gray hairs appear in the start of the graying process? Due to the fact that each hair follicle grows independently, individuals tend to exhibit single strands of gray hair before the entire head turns to gray.
Recently, a team of researchers in Europe discovered that catalase, an enzyme involved in the breakdown of hydrogen peroxide, is responsible for causing vitiligo. This genetic disorder is characterized by patches of skin that lack pigment. Because gray hair also results from loss of pigment, researchers believe the accumulation of hydrogen peroxide may be a reason for graying hair. The cell only produces a small amount of the chemical, but this can create a build up over time. The researchers believe that these elevated levels of hydrogen peroxide block the synthesis of melanin. Knowing the process behind gray hair puts scientists one step closer to identifying the relationship that stress plays as well. Regardless if scientists find a correlation between stress levels and the graying process, its ultimately believed that genetics are the primary determining factor.
An understanding of the mechanisms behind gray hair is not just interesting, but has the potential to uncover the secrets behind aging on a molecular perspective. Perhaps the device responsible for destroying hair pigment cells could aid in destroying the cells responsible for cancer, leading to more effective treatment options for melanoma in particular.
AHHH! This is a topic I do not want to think about. All of my elder relatives have already turned gray and I spontaneously find random gray hairs. I have always wonder why I will find a hair that is only half gray. It is interesting to know that each grows independently and may turn gray due to an abundance of hydrogen peroxide.
ReplyDeleteThis is extremely interesting because I have also thought that gray hair was simply more genetic than any other factors. Some people have more stress than others and still have full pigment while others who are happy and carefree are graying early. I would have never guessed that hydrogen peroxide accumulation would be the reason for graying.
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