You may despair at the silver threading though your hair or you may wear your gray like a badge of honor; a testament to your years and your wisdom. Either way, the reasons for gray hair is not something that we yet understand fully; buy which most commonly are.
Heredity and genetic factors
One of the most significant factors that govern the graying of hair is our genes. If we have a genetic predisposition to graying early in life, there is really little that we can do about it. Though gene therapy may one day make it possible to turn white hair into colored hair once again, this is far from reality right now.
As of now there is really very little one can do about going gray at 35 if their parent or parents did the same. You can color your hair or you can wear a hat to disguise it; but you cannot stop your hair from losing color.
People with conditions such as anemia, or thyroid problems, being unable to absorb certain vitamins into the body can have gray hair before their time.
Also skin disorders such as vitiligo (the condition that caused Michael Jackson’s skin to turn white) can turn hair gray since the whitening of the skin and the graying of the hair occurs due to the same de-pigmentation (loss of pigment or color).
Sometimes it could be a deficiency of certain vitamins or other nutrients that make a person go gray. These deficiencies, if detected, could be corrected to arrest the graying of the hair. Sometimes it is medications that contribute to the hair going gray and if discontinued, the problem may resolve. Eating disorders may also cause nutritional deficiencies that contribute to gray hair.
Environmental and other pollutants
Smokers are more likely to go gray before their time, because in a sense smoking pollutes the inside of the body (ever heard the term Smoker’s Face, which discolors the skin and nails as well?). Even external pollutants could contribute to the hair going gray. Pesticides and other chemicals that get into the body by one or other means can cause disturbances and imbalances in the body leading to the hair not retaining its pigment.
Stress turning the hair gray is not just an old wives tale. Stress, grief and depression can cause hormonal changes that in turn the hair gray before its time.