Gray hair is a natural part of the aging process and occurs when the pigment cells in hair follicles gradually die, resulting in fewer pigment cells to produce melanin. Here are some key points about what causes gray hair:

• Aging: As people continue to age, fewer pigment cells will be around to produce melanin, and eventually, the hair will look completely gray.

• Genetics: How early we get gray hair is determined by our genes. This means that most of us will start having gray hairs around the same age that our parents or grandparents first did.

• Nutritional deficiencies: Copper and iron deficiency can cause graying of hair. A study reported significantly lower levels of copper in patients with premature graying of hair when compared to the control group.

• Medical conditions: In rare cases, premature graying can be a sign of a medical issue, such as vitiligo, a condition that causes the skin to lose its pigmentation.

A 2023 study suggests that stem cells may get stuck as hair ages and lose their ability to mature and maintain hair color. Certain stem cells have a unique ability to transition between growth compartments in follicles, and these cells lose the ability to move with age, resulting in greyness. The scientists believe that if their findings hold true for humans, they could open up a potential way to reverse or prevent gray hair by helping jammed cells to move again between developing hair follicle compartments.