Grey hair and premature greying

The human skin contains three pigments in the entire body: haemoglobin, carotenoids and melanin pigments. However, melanins are responsible for the pigmentation (colour) in the skin and the hair. 

• Melanin is formed by melanocytes which are specialized pigment cells that place themselves at the openings of the skin’s surface, also known as hair follicles, through which hair grows.
• Hair follicles contain two types of melanin, namely eumelanin and pheomelanin.
• A single hair follicle contains either of the two types of melanin.
• The black-brown pigment called eumelanin gives the black and brown colour to the hair.
• The yellow or red pigment called pheomelanin gives auburn and blonde colour to the hair.

There are possibly two theories that could explain the greying of hair:

• With growing age, the melanocyte activity (melanin production in the hair) slows down or stops, thus decreasing the pigment our hair receives which causes greying of hair.
• Another reason is thought to be hidden in the hair cycle. Human hair essentially undergoes three stages of hair cycle: anagen, catagen, and telogen phases. The hair grows during the anagen phase, followed by a transitional period (where no change takes place) of the catagen phase. After the catagen phase, telogen phase starts when the hair releases from the follicle and falls off.

Hair is actively pigmented during the anagen phase and the pigmentation stops during the catagen phase and absent during telogen.

When greying of hair starts before the age of 20 in Caucasians, before 25 in Asians and before 30 in Africans, it is called premature greying of hair or premature canities.

Though there is no exact cause of premature greying of hair, there are some conditions that could be associated with premature greying of hair: 

• Genetic factors: Premature greying could be seen in generations.
• Hypothyroidism: People with hypothyroidism (decreased levels of thyroid hormone in the body) may suffer from premature greying.
• Protein loss: Chronic protein loss due to kwashiorkor, nephrosis, celiac disease, and other malabsorption disorders could lead to premature greying.
• Mineral deficiency: Deficiency of iron and copper is associated with premature greying.
• Vitamin deficiency: In most cases, premature greying is due to the deficiency of Vitamin B12.
• Topically-applied agents: Dithranol, chrysarobin and resorcinol, used to treat conditions like psoriasis may cause premature greying.
• Vitiligo: This condition causes melanocytes to be lost or destroyed because the immune system starts attacking its own melanocytes.
• Von Recklinghausen’s disease (Neurofibromatosis): It is a genetic disease which involves the growth of tumours along nerves and abnormal development of the bones and skin.
• Book’s syndrome: In this syndrome, the skin, sweat glands, hair, nails, teeth and mucous membranes get affected simultaneously.
• Down syndrome: It is a genetic disorder presenting with a flattened face and nose, short neck, mental disability and greying of hair.
• Werner’s syndrome: It is a genetic disease where the affected person may have skin changes, juvenile cataracts (cataract in children), short stature and signs of premature ageing.
• Medications: Use of certain medications like mephenesin (a muscle relaxant), chloroquine (used for malaria), triparanol (used to reduce cholesterol), phenylthiourea (used in DNA testing), fluorobutyrophenone and dixyrazine (used to treat various psychiatric disorders) could possibly lead to greying of hair.
• Stress: Studies have shown that stress hormones (adrenaline, cortisol) promote the migration of melanocyte cells away from the follicle, leading to premature greying.

Since the cause of the greying is not clear, there is no effective therapy available. Research is still being done to find efficient treatment for premature greying. Meanwhile, other treatment modalities are:

• The most conservative treatment involves colouring of grey hair. It can be done with natural dyes like Henna, Amalaki (Emblica officinalis), Bhringaraj (Eclipta alba), mooncake seed tree (Sterculia platanifolia), and the lotus tree (Zizyphus spina-christi).
• Topical anti-ageing compounds like green tea polyphenols, selenium, copper, phytoestrogens and melatonin can also be used to decrease the intensity of greying.
• Vitamin B supplements along with rich healthy diet and thyroxine tablets are given in case of vitamin B deficiency and hypothyroidism.
• A study has proved that 200mg of ap-aminobenzoic acid (PABA) for two months leads to darkening of hair for a limited period of time. Thus PABA has proved to be a temporary hair darkening drug. 
• Taking calcium pantothenate 200 mg/day along with the removal of grey hair from the scalp has given effective results in repigmentation of hair.
• Cinnamidopropyltrimonium chloride is a UV absorber and is used for photoprotection of hair. It can be used at home as it is available in shampoo form.
• Psoralens with sunlight as the source of ultraviolet A-rays (PUVASOL) is a phototherapy that stimulates melanocytes into the follicles, leading to initiation of pigmentation.
• Solid lipid nanoparticles of UV blockers have been developed for use on skin and hair which provide photoprotection by reacting and scattering ultraviolet radiation (UVR) on its own.
• Use of hormonal anti-ageing protocols containing recombinant human growth hormone has resulted in improvement of hair thickness, hair growth, and in some cases darkening of hair.
• Delivery of melanin into hair follicles through the liposomes has resulted in darkening of hair follicles. Liposomes are vesicles used to deliver microscopic substances such as drugs or DNA to the cells of the body. They can be used to restore hair colour via molecular and gene therapy.

Greying of hair is a natural process that occurs as you age. Melanin production in hair reduces with age, and hence the older you are the whiter your hair will turn. Premature greying is a problem that many face, but it doesn’t have a single common cause. It can happen due to genetic factors, deficiency of nutrients like vitamins and proteins, pre-existing health conditions like hypothyroidism, vitiligo, etc, stress or use of certain medications. While nutrient supplements and healthy lifestyle choices can stop or prevent premature greying, the most effective treatment - and the most popular one - is colouring of hair.