The science behind those greying hairs

The science behind those greying hairs | Dr Mary McMillan

It finally happened. I suppose I should have seen it coming, given I am one of what is now being referred to as a generation of "ageing millennials".

Or perhaps it's just the ongoing stress of the pandemic that brought it on. Whatever the reason, there is no denying it. I have my first grey hair.

Of course there's absolutely nothing wrong with greying hair. It's a completely natural process and, sooner or later, it happens to us all, whether we're ready to embrace it or not.

But why? The colour in our hair comes from melanins, pigmented molecules produced by specialised cells within our hair follicles. These cells, called melanocytes, infuse our hairs with pigment as they grow.

But just like any other cells, melanocytes age.

And as they do they stop producing pigment, and our hair turns grey.

The same process happens to the hair all over our bodies - it's just most obvious when it's happening on our heads.

Most people start to see grey hairs between their mid-30s and mid-40s, so in that respect I'm bang on time.

The timing of greying hair seems to be, at least partially, controlled by our genes.

One particular gene, the IRF4 gene, has been linked to premature greying.

It seems a specific variation of these gene might impact on the ability of melanocytes to produce pigment.

While genes might be one factor, the environment and lifestyle choices also play a role in going grey.

Smokers tend to go grey earlier than non-smokers, as do some people who have vitamin B or other nutrient deficiencies.

Other health conditions - things like thyroid conditions - can also slowly send you grey.

But what about stress? Is there any truth to the old adage that stress will turn your hair white?

There have been a couple of studies in the last few years that have found some links between stress and greying hair.

It's been proposed that some of the hormones produced when we're stressed can interfere with pigment production or inactivate our melanocytes.

However, we should keep in mind that some of these studies have been done in mice, which have different hair and follicle structures compared to humans.

While stress could be a contributing factor, it's probably unlikely that the pandemic is actually sending me grey.

Instead it's just another sign, along with my dodgy hip and increasing frown lines, that age does indeed catch up with us all.

Dr Mary McMillan is a senior lecturer at the School of Science and Technology, University of New England.

This story The science behind those greying hairs | Dr Mary McMillan first appeared on The Canberra Times.