Medical factors linked to premature graying of hair

Medical experts have identified several key factors contributing to premature graying of hair. Research published in the Italian Dermatology Online Journal indicates that smokers are approximately 2.5 times more likely to experience graying before the age of 30 compared to non-smokers.

Chemical exposure is another significant factor. Certain hair dyes and shampoos containing hydrogen peroxide or other substances can affect melanin levels, leading to loss of natural pigment. Additionally, a study from New York University published in Nature Medicine suggests that intense or chronic stress can damage the cells responsible for maintaining hair color.

Underlying medical conditions and nutritional deficiencies also play critical roles. Autoimmune diseases, thyroid dysfunction, and alopecia areata have been linked to early graying. Furthermore, low levels of essential nutrients—including vitamins B6, B12, D, E, and biotin, as well as iron (serum ferritin)—are strongly associated with premature hair color changes, particularly in individuals under 25.