|Before our hair pops out of our scalp it is actually completely white. It gets its colour from a group of pigment molecules called melanin. Melanin determines our hair colour, skin colour and even eye colour. There are two types of melanin: Eumelanin that produces dark shades and Pheomelanin that produce light shades. The proportion of these two types determines our hair colour. How does the colour get into our hair?|
Every hair follicle contains cells that are called melanocytes, these cells produce melanin. As the hair grows, the melanocytes inject the melanin pigments into your hair. As the hair grows out of the head it gets dyed with its natural hue. Over time our melanocytes produce less pigment causing our hair to lighten as we age.
The second culprit is hydrogen peroxide, the same stuff we use to bleach our hair with. We produce hydrogen peroxide naturally, however, an enzyme that is called catalase breaks down the hydrogen peroxide and keeps its concentration in check. However, when we get older, the follicle is not able to produce enough catalase, and therefore higher concentrations of hydrogen peroxide, the hydrogen peroxide then affects the melanocytes causing them to produce even less melanin.
Does stress actually cause your hair to grey?
Consider stress one of those outside factors. “While there is conflicting research on whether stress can cause grey hair, there has been a study published by NYU concluding that hair cells that produce pigment may degenerate when a person is stressed. In addition, stress can trigger a common condition called telogen effluvium. This causes hair to shed about three times faster than normal. When a person is middle-aged, the hair that can grow back may be grey rather than colored,” explains Hayag. “Lastly, oxidative stress in the body has been linked to gray hair. Oxidative stress causes imbalances in the body when free radicals damage cells. When there aren’t enough antioxidants to counteract the damaging effects of free radicals, it can lead to aging and diseases such as vitiligo.”