Skin and hair contribute immensely to human communication. Hair length, colour, and style play an important role in people’s physical appearance and self-perception. Human beings are unique amongst primates in having very thick, long, and highly pigmented scalp hair. This is likely to have provided one or more survival benefits to the humans during the process of evolution.
Firstly, selective and avid binding of toxins and metals to melanin pigment aids in preventing the buildup of toxic metals from fish species which concentrate heavy metals, especially in human development along sea coasts and riverbanks.
Secondly, reactive quinone intermediates generated during melanin synthesis possess potent antibacterial properties. Lastly, deep brown-black hair present in 90% of the world’s population protects against sunstroke, and its melanin aids very efficient and fast exchange of ion transport and effluxes for adequate salt balance.
REASONS FOR GREY HAIR
Graying of hair prematurely is an important reason for lower self-esteem, often interfering with socio-cultural adjustment. The onset and progression of greying or canities correlate very closely with chronological ageing, and occur in varying degrees in all individuals eventually, regardless of gender or race. Premature hair may occur because of major autosomal dominant condition with association of various autoimmune or premature ageing syndromes.
Full range of colour from normal to white can be seen both along individual hair and from hair to hair, and admixture of pigmented and white hair is believed to give the appearance of grey.
CHARACTERISTICS OF GRAY HAIR
- Gray hair is believed to be coarser, stiffer, and less manageable than pigmented hair. reported that grey hair undergoes more severe UV damage and needs more UV protection than dark brown hair.
- Gray hair often fails to hold a temporary or permanent set and is more resistant to incorporating artificial colour possibly due to changes in the underlying substructure of the hair fibre.
- Melanin transfer possibly decreases keratinocyte turnover and increases keratinocyte terminal differentiation.
- Aging hair follicles may thus reprogram their matrix keratinocytes to increase production of medullary rather than cortical keratinocytes resulting in an enlarged and collapsed medulla, forming a central cavity in grey and white hair.
- This may provide enhanced insulation to compensate for the loss of sunlight-absorbing and heat-trapping properties of pigmented dark hair.
- Thickness, growth rate, and hair shaft elongation in non-melanized hair are significantly greater than in melanized hair.
TREATMENT FOR GREY HAIR
- Home remedies: Certain home remedies have been found useful in the prevention and treatment of premature greying of hair. The use of Indian gooseberry or amla which is an important hair tonic for enriching hair growth and hair pigmentation. This oil is very functional in preventing further greying.
- Hair Dye: The ground and mixed paste of henna leaves, which is consistently boiled in coconut oil to get a darkish oil, is being used as a hair dye to treat grey hair. Washing hair with concentrated tea extract twice a week is useful in colouring grey hair to brown or black.