Grey is the new black. Spring 2015 brings another marker for embracing the natural beauty of grey hair. Joan Didion is the new face of Céline, Joni Mitchel for Saint Laurent, while Gerard Butler has been centre stage for Hugo Boss since October 2014. Over the past few years even fashion icons such as Kate Moss have been embracing the mature look. Even the younger celebs Marina Diamandis and Lady Gaga keep up (albeit with a stock of hair dye). Speckled, pepper, snowy … whatever you want to call it, who doesn’t want to look like Helen Mirren or George Clooney when they’re older. We’re here to explain what causes hair to lose its colour, how some people can get ahead of the game with premature greying, and to debunk some of the myths and madness.

Science behind hair colour
In simple terms, the colour of our hair is determined by the amount of melanin present in the middle layer of the hair shaft, which is called the cortex. Melanin is a pigment produced by cells called melanocytes which are found in the epidermis across the body. Melanocytes break down the amino acid tyrosine to make two types of melanin; eumelanin and pheomelanin. This process by which melanin is made is called melanogenesis (‘genesis’ literally meaning the formation or production of something).

Hair, skin and eye colour all depend on the ratio between these two types of melanin. Eumelanin contributes brown and black colours to hair whilst pheomelanin is responsible for red. Someone with blonde hair will have very low levels of both, whilst a red head usually has low eumelanin and high pheomelanin. Those of us with dark hair have high levels of eumelanin. The proportion of the two melanin types is largely down to genetics. Albinism is a disorder where the melanocytes cannot break down tyrosine so cannot produce melanin meaning the skin and hair are left white. Simples!

Bulbar melanocytes, the cells which produce melanin that add colour to the hair shaft, are found in the hair follicle itself. The hair shaft is made up of mainly keratin and other colourless proteins so when melanogenesis is interrupted, melanin is no longer made and isn’t injected into the cortex of the hair shaft as it grows. From this point, the hair will appear white. Grey hair is very slightly different. If someone has a strong expression of eumelanin (such as those of us with dark hair), some eumelanin may still be produced and incorporated into the hair shaft even after much of the melanin production is lost. There is not enough eumelanin to make the hair black but there is still enough to create a silvery glisten. Enter the ‘silver foxes’ of the modern day!

Why does grey hair occur with age?
Bulbar melanocytes in the follicles are more sensitive to ageing than melanocytes in the epidermis, although we’re not yet certain exactly why this is. The idea of increased oxidative damage from free radicals with age is central to our understanding of hair greying. It is thought the ageing is a result of free radicals causing oxidation and damage to the bulbar melanocytes. As we get older our body chemistry changes and fewer antioxidants are produced (the enzyme ‘catalase’ as an example). Catalase usually controls levels of hydrogen peroxide in cells, but as we get older catalase levels decrease and the melanocytes are unable to cope with the high levels of hydrogen peroxide. This build-up of this cellular stress eventually halts melanogenesis.

So we’re all doomed to go grey?
This all sounds a little drastic and dreary, but not quite as many people are going as grey as you may think. A study of 4192 healthy volunteers from a range of ethic and geographical origins observed that whilst 74% of people between 45 and 65 years did have grey hair, the average ‘coverage’ of this greyness was only 27% (this was much less than previously anticipated). The study also disproved the myth that 50% of people more than 50% grey hair at age 50 (that was way too many 50s to be true anyway!). In fact, results showed that only 6-23% of people at 50 have over 50% grey coverage. Asian and African men showed significantly less percentage of grey hair than Caucasians (again, supporting the idea that genetics have a big influence on going grey!).

Premature grey hair
There is a genetic link for premature grey hair so if a family member went salt and pepper early it is more likely that the grey could start creeping up at a younger age for you too (although this it is not a dead cert). Premature greying could also be caused by a number of lifestyle choices. Deficiency of vitamin D – from poor diet and lack of sunlight – can impact hair greying, as can underlying health problems and excessive use of hair treatments and products that take their toll on hair follicles. There is also evidence to suggest that smoking and obesity can increase risk of premature hair loss and greying in both men and women.

We can confirm that neither stress nor trauma have been shown to turn your hair grey over a short period of time, although it is thought that continuously high stress levels can contribute over a period of years.

Grey/white hair is a symbol of maturity and wisdom. Whilst some of us may choose to put off the wisdom a little while longer and dye ourselves back into a coloured crown, going grey isn’t the worst thing in the world! Whether you chose to grow grey gracefully or disgracefully is up to you, but remember, going grey is nothing to be embarrassed about. It’s definitely more than a little ‘Vogue’.

Hair follicle pigmentation – Journal of Investigative Dermatology
Graying: Gerontobiology of the hair follicle pigmentary unit – Experimental Gerontology
Greying of human hair: a worldwide study revisiting the ’50 rule of thumb’ – The British Journal of Dermatology
Premature grey hair and hair loss among smokers: a new opportunity for health education – BMJ
Age induced hair greying – Journal of Cosmetic Dermatology.
Images: http://ethnichealthcourt.com/2014/07/03/onion-juice-promotes-reversal-of-grey-hair/, http://www.nlm.nih.gov/medlineplus/ency/imagepages/8669.htm