Why do we develop grey or white hair

1 Pigment cells die

As people age the pigment cells in their hair follicles that produce melanin die. With the reduced number of pigment cells the new hairs produced become transparent thus appearing grey or white.
2 Genetic causes

Genetics affect the age at which grey hair is developed. A person can get Grey hair earlier if his parents had Grey hair earlier in their lives.
3 Vitamin deficiency

vitamin Deficiency can accelerate the growth of Grey hair. Vitamins such as B12 and minerals such as Zinc and copper are required to keep the hair healthy and pigmented.
4 Smoking can cause premature grey hair development

Smoking is known to produce free radicals which in turn cause oxidative stress. This oxidative stress makes melanin less effective in keeping the hair colored.
5 Junk food can accelerate grey hair growth

A poor diet and especially junk food can accelerate the growth of grey hair.
6 Stress

Stress is believed to accelerate the growth of grey hair.
7 Shocks or trauma

Shocks or trauma can make a person's hair turn grey much faster and in a short period of time.
8 Hormonal imbalance

hormonal imbalance can promote the growth of grey hair and let the hair lose its color faster.
9 Anemia

Anemia is known to accelerate the growth of white hair.
10 Thyroid problems

If the thyroid gland fails to produce enough hormone, the hair might turn grey faster.
11 Hair not getting sufficient air

Some commercial products might prevent the hair from getting enough air and as a result, growth of grey hair might be accelerated.
12 Drinking

Drinking can accelerate the growth of Grey hair.