Heredity is strongly correlated w graying but asking a dermatologist might be helpful. Dr Pam

While there is no guaranteed way to prevent premature graying, maintaining a balanced diet, managing stress levels, avoiding smoking, practicing gentle hair care, and considering specialized hair care products may help promote hair health. Embracing the natural graying process can also be empowering.

I would focus on regular intake of sufficient quantities of zinc and zinc rich foods like almonds. Reduce stress overall.

Avoid hair dyes. Avoid extreme heat (e.g, curlers, hair irons, etc.).

From your question, I would say that your family's tendency to premature graying is due to genetics. When graying hair is the result of genetics, there is little that a person can do to stop this from happening. If premature graying is due to either a nutritional deficiency in vitamin B-12 or a medical condition related to the pituitary or thymus gland, it may be possible to reverse premature graying by correcting these problems through treatment.