The onset of greyness in many ways is similar to hair loss.
It begins rather slowly, first affecting a single hair strand, and then snowballs to consume much of the rest of the head.
The diagnosis is certainly the same. On an otherwise normal day, during a casual glance in the mirror, you spot that something looks different.
You’ve identified the first grey, either at the front of the head or on one of the sides. You may decide to pluck it out at first, but over time, it re-grows and other greys sprout.
Whilst for some the sight of the first grey can induce mild panic, it's important to remember that grey hair, like wrinkles, and to a large extent hair loss, is simply a sign of aging.
Indeed, dermatologists have coined the “50-50-50 rule” for grey hair; at the age of 50, about 50% of the population has 50% grey hair.
So what's the science behind grey hair?
Hair colour is all about pigmentation… or lack of it.
Initially, our hair is white. It gets its natural colour from a type of pigment called melanin. Melanin is made up of specialised pigment cells called melanocytes which are located at the site of hair follicles where the hair strands grow.
As hair is being formed, melanocytes inject melanin into cells specifically containing keratin, the protein that makes up our hair, skin, and nails. The injection of this pigment into hair cells gives it its natural colour.
The onset of greyness is due to our “melanogentic clock”. As we age, melanocyte activity slows. This is due to a build-up of hydrogen peroxide that occurs naturally in our hair follicles and blocks the production of melanin.
The effect is that new hair receives less pigment, resulting in them having a grey-white colour, which is the natural colour of keratin.
However, men don't go fully grey all at once. At any one time, you are likely to have head hair with a combination of your normal hair colour and hair with a grey/white colour.
This is because the average hair-cycle is 3-years (greyness affect new hairs) and each strand of hair has its own melanocytes (so individually impacted by the melanogentic clock).
Another common query is the cause of grey hair.
As indicated above, grey hair is an inherited trait. If your parents went grey early there is a possibility that you will too.
However, just like hair loss, there other factors that can contribute and speed up the greying process.
These include stress and smoking, both of which can cause hair to grey prematurely by affecting the stem cells that are responsible for regenerating the hair pigment.
Healthy eating can also help, although it's by no means a miracle cure. Hair consists of protein (keratin), so it it's important to eat foods like eggs and fish which are good sources of first-class protein.
You should also be aware that some health conditions are thought to cause premature greying, such as diabetes, pernicious anemia and thyroid problems.
So, if you've started greying, what can you do about it?
The first thing to decide is whether you actually want to take action or go au naturale.
Taking action is often a huge hassle as the dying process needs to be done regularly or the roots start to show through.
Many men are now embracing their grey hair and letting it grow naturally. Grey hair can be just as eye-catching as any other colour if you style it in a way that shows the world you’re still in the game.
Indeed, there are certain hair styles known to accentuate greyness. For example, if you have thick hair then a short on sides/long on top is recommended, as this displays the different tones of grey in the best way.
Research suggests that if you get the hair cut right, a sophisticated greying mane may be effective in attracting the opposite sex...
A recent study conducted by Match.com has found that 72% of women find a man with grey hair “hot”.
Perhaps it's better to follow Zayn Malik and dye your hair grey instead.