As it turns out, grey hair could be protecting us from cancer.

The pigment that gives our hair colour is produced by cells called melanocytes and their number is kept topped up by stem cells. Hair starts going grey when the number of stem cells in hair follicles decline.

But now studies are suggesting the reason stem cells decline is that as they are increasingly exposed to radiation and chemicals that harm DNA (like UVA rays and parabens), they become damaged and turn in to melancoytes. This ultimately leads to fewer melanocytes as there are fewer stem cells capable of topping up the melanocyte pool – and more grey hair. But it’s this process, scientists suggests, that is protecting us as it discourages the proliferation of cells with damaged DNA, which could pass on mutations.

But aren’t we at risk of undoing all that good work nature’s performing on our behalf by dying the grey hair back again? If you’re worried by reports that hair dye may cause cancer, know that according to Cancer Research, there is virtually no connection between the two. Other lifestyle factors like diet and smoking are much more of a concern, they say.

If you’d still rather err on the side of caution, opt for semi-permanent vegetable-based dye or henna-based dye, or at least alternate between these and permanent dyes. Also, try colouring your hair less regularly – a few silver hairs catch the light and can be very flattering – and always use a good anti-fade hair care system in between dye jobs. I like the new Pureology range (from £16.50; enq 0800 7833026), and the Jo Hansford Colour Care range (from £14; enq 020

7409 7020)

Grey hair today, not gone tomorrow. Hopefully.