Here is diagram of a hair bulb. 

Inside each of our hair bulbs, is our hair dermal papilla cells. The papilla cells determine our hair formation and our hair life cycles.  

On the papilla, we have our melanocytes which are well known for their role in skin pigmentation, and their ability to produce and distribute melanin, a pigment which determines our natural hair color. Melanin that is produced is transferred to the keratinocytes which make up the cells in the hair shaft

The greying process, also known as Canities, is caused by the loss of hair color, which also means that the melanocytes are not producing as much melanin as before, therefore they are unable to transfer the melanin to the kerinocytes. When this happens, your hair appears to turn grey or white.

Another reason for hair whitening is the accumulation of hydrogen peroxide.

This chemical compound is naturally present in the follicle and has powerful oxidant properties. It is usually neutralised by an anti-oxidant enzyme called catalase. With age, the activity of catalase and hydrogen slows down and hydrogen peroxide builds up, leading to the discolouration of hair pigments and also the deterioration of melanocytes.

Many people are not worried as they feel that when their hair turns white, they can simply color it or leave it white. However, when your hair turns white, it also loses its softness and becomes brittle. Each hair strand will not be as thick or dense as before. 

Let’s look at some other common causes for white hair: 

• Genetics: Premature greying of a person’s hair is largely connected to genetics, according to a 2013 report in the Indian Journal of Dermatology, Venereology and Leprology.
  

• Race and ethnicity: Premature greying in caucasians can start as early as 20 years old, while a person can be as young as 25 years old among asians, and 30 years in African-Americans populations, according to the same 2013 study.
  

• Oxidative stress: While greying is mostly genetic, oxidative stress in the body may play a part when the process happens prematurely. Oxidative stress causes imbalances when antioxidants are not enough to counteract the damaging effects of free radicals. Free radicals are unstable molecules that damage cells, contributing to aging and disease.
  

• Real-life Stress Factors: One study from New York University, reported in Nature Medicine, finds that the cells responsible for hair color can be depleted when the body is under stress. When President Obama went into the White House, he had a full head of black hair. Years layer, he left the office with almost all of his hair fully white. Researchers in a recent study found that mice exposed to stress had more depleted melanocyte stem cells in their hair follicles. The more stressed the mice, the less pigment their melanocytes produced.
  

• External Stress Factors: Chemical hair dyes and hair products, even shampoos, can contribute to premature hair greying. Many of these products contain harmful ingredients that decrease melanin. Hydrogen peroxide, which is in many hair dyes, is one such harmful chemical. Excessive use of products that bleach hair will also eventually cause it to turn white.

• Vitamin Deficiencies: Any deficiencies of vitamin B-6, B-12, biotin, vitamin D, or vitamin E can contribute to premature greying. One 2015 report in the journal Development notes various deficiency studies on vitamin D-3, vitamin B-12, and copper and their connection to greying hair. It finds nutritional deficiencies affect pigmentation, suggesting color can return with vitamin supplementation.
  

• Smoking: A study from 2013 reported in the Italian Dermatology Online Journal, shows that smokers’ hair are 2.5 times more likely to start greying before age 30 versus non-smokers. A 2015 study in the Journal of the American Academy of Dermatology also demonstrated that smoking is linked to premature white hair in young men.
  
  
• Certain medical conditions including autoimmune diseases, may increase a person’s risk for greying early. In fact, research published in 2008 showed a connection between hair abnormalities and thyroid dysfunction. White hair is also common in alopecia areata, an autoimmune skin condition that causes hair loss on the scalp, face and other parts of the body. When the hair grows back, it tends to be white due to melanin deficiency.
  
  
• Growing Old

 Now that you know the causes, how can we prevent or treat white/grey hair?

1) Phyto RE30 is the World’s 1st Anti-Grey Hair Treatment capable of re-pigmenting hair at the root while restoring strength and suppleness. Formulated with an innovative patented ingredient peptide RE30 & purple tulip extract which PHYTO took 6 years to develop. 

PIGMENTATION BOOST: 

Increase of melanin synthesis & Increase of melanin transfer. 

PROTECTION FROM DEPIGMENTATION: 

Catalase booster & Hydrogen peroxide inhibitor. 77% success rate

2) Eating more antioxidants: Eating a diet with lots of antioxidant-rich foods, including vegetables and fruits, may help to prevent hair from graying. A person’s diet plays a part in preventing white hair. A diet rich in antioxidants can reduce oxidative stress. For example, seafood, eggs, and meats are good sources of vitamin B-12, and milk, salmon, and cheese are excellent sources of vitamin D. Vitamin supplements that are available over the counter can also correct deficiencies like Phytophanere Dietary Supplement will give you what you need to maintain black hair with Biotin and Vitamins Bs!

3) Quitting smoking & try to limit stress: Smoking has adverse effects on the body and contributes to white hair. 

4) Be nicer to your hair: Over washing your hair can actually damage it. Be mindful of the products you use to wash, dye, and style your hair. Bleaching and harsh shampoos can lead to damage and early white hairs.