Why Do Hairs Go Grey?

Most people start to find their first greys at the age of 30, typically starting at the temples then gradually spreading across the rest of the hairline. By the age of 50 this "salt and pepper" look usually applies to around 50% of the hair.

So why do hairs turn grey? Cells known as melanocytes are responsible for producing hair colour. As follicles develop in utero they migrate into the hair bulb and create a colour pigment that's integrated into the fibre. The result can be natural shades ranging from strawberry blonde and light ash to chestnut brown and jet black. Without the presence of a pigment the colour reverts to white, silver or grey.

The all-important role of melanins

The exact colour depends on the production of melanins, a group of natural, colour-creating pigments possessed by mot living organisms. Eumelanins produce brown and black pigments, while pheomelanins are responsible for tones of red and yellow.

When it comes to age-induced grey hairs, scientists pin the transition on genetic factors, though the controlling genes have not yet been identified. Basically, at the end of each hair cycle pigment-producing melanocytes become damaged or die off completely. This means the melanocyte stem cell reservoir is no longer able to replenish the bulb with pigmentation which sees hair revert to grey.

Beyond the ageing process, several factors can interfere with the balance of melanins, including melanocyte-stimulating hormones and estrogen and progesterone, which can darken lighter shades of brown and blonde. Stress is also blamed as a trigger for grey hairs, while autoimmune diseases like alopecia areata and vitiligo can also hinder the work of melanocytes.

Preserving colour

Recently, a team of French scientists made a breakthrough discovery and identified a series of agents that actively protect melanocytes against damage. The technique stimulates pigment production in the hair follicle by duplicating the work of a naturally occurring antioxidant enzyme called DOPAchrome tautomerase, which protects melanocytes from oxidative damage and promotes the cyclic renewal of pigmentation. The team are now working on formulating the agents into a product that will actively protect hair follicle melanocytes and work to preserve natural pigmentation.

Want to know more about the latest techniques supporting scientific research across the globe. Offering expert commentary from Paul Walker, senior development specialist at Socotec, 'Characterising Unknowns: Behind the Scenes of Chemical Investigation' spotlights the importance of effectively and precisely identifying unknown materials and substances.