Grey hair goes under the microscope this week when Professor Mary Beard, a renowned proponent of the natural look, investigates the impact of an ageing barnet for the Radio 4 documentary Glad to be Grey.
Beard may favour grey locks but it is not a sentiment shared by many. We in the UK spend about £350,000 million a year on hair dye (and considerably more on having it applied), with most of that going on products that mask the signs of ageing. However, advancing years aren’t the only reason some people turn grey; earlier than normal change can be a reflection of their lifestyle and underlying health.
Before we get to the science I feel duty bound to tackle the elephant in the room. Even a cursory glance at the photograph above this column reveals that I have unfeasibly dark hair for a 53-year-old. Friends, work colleagues and even my youngest sister think I dye my hair, something they have ribbed me about for a decade. And in my part of the world — rural Gloucestershire — there is only one thing worse than a man who dyes his hair, and that’s one who pretends he doesn’t. But, for the record, I don’t.
Hair colour comes from pigment-producing cells in the bulb at the base of each hair. When these start to fail, the colourless hairs that grow give an overall impression of greyness. The process is normally gradual and tends to start with hairs around the temple before spreading to the crown and the back of the head. The age at which the process starts varies depending on a number of factors including familial traits and ethnic background, but by the age of 50 half the hairs on the head of an average white Briton will be grey.
This type of gradual greying may not be desirable for some, but it is perfectly normal and simply a reflection of your age. Yet for others who turn grey unusually early — before the age of 20 in white people, 25 in Asians and 30 in people of African descent — it can be a sign of underlying issues.
Advertisement
Most people with premature greying will have inherited the predisposition from one or both parents, but for some it may have been accelerated by their lifestyle or associated health problems. Although the exact nature of the various links remain poorly understood, premature greying is associated with smoking, drug abuse and vitamin and mineral deficiencies (B12, iron, vitamin D and calcium have all been implicated over the years). Sunlight is a factor too since ultra-violet light can damage the delicate cells in the scalp responsible for maintaining hair colour and accelerate depigmentation.
Perhaps the most significant association is with a range of autoimmune disorders where the body’s defence system starts attacking tissues including the hair follicles. Recognised examples include vitiligo (patchy depigmentation of the skin), thyroid disorders and pernicious anaemia (a type of vitamin B12 deficiency).
Stress is another often-cited factor — “you are turning me grey” — and research suggests this could be a knock-on effect of raised cortisol levels (stress hormones) damaging cells in the scalp. Yet, contrary to the old wives’ tale, a sudden shock or severe illness can’t turn you grey overnight.
Like most doctors I have had a few patients who have become a lot greyer after serious illnesses but the process takes months. Whatever the injury to the pigment-producing cells, it can only change hair colour from that time on. The existing colour laid down in the hair shaft will remain until it grows or falls out. Brown hair for instance can’t turn grey unless you bleach the colour out of it.
Grey hair may be widely regarded as ageing, but I quite like it — in both men and women. Indeed in my line of work it can give you a certain air of authority, which is exactly the opposite impression conveyed by a suspiciously dark thatch. As I have learnt to my cost.
Advertisement
Glad to be Grey is broadcast this Friday on Radio 4 at 11am
What happens to your hair as you get older
■ As well as turning grey our hair tends to thin naturally with age, even if you don’t develop the classic receding hairline or bald patch.
■ When we are born we have about 1,000 follicles per square centimetre of the scalp. By our mid-twenties that has fallen to 600 and it halves again by the age of 50.
■ Redheads tend to have fewer follicles than those with other hair colours.
Q&A
Q. I have had an annoying dry cough ever since catching a cold before Christmas. My GP has checked me over and thinks it may be one of my blood-pressure medicines, but I have been taking it for two years without a problem and I am reluctant to change. Could it really be causing problems after all this time?
A. You don’t say which tablet your doctor has blamed but if ends in -pril (such as ramopril or perindopril), it could well be the cause, and stopping it is the only way to be sure.
The culprit is a family of drugs called ACE inhibitors with about one in ten people who are taking them developing a nagging dry cough. It can start almost immediately but sometimes not until years later, and in my experience often follows a viral infection (it’s one of the things I look for when patients come in saying they caught a cough and it has been bothering them ever since).
Advertisement
Your doctor can switch you to a related drug that is just as effective at reducing your blood pressure but shouldn’t cause the cough. If the ACE inhibitor is responsible you should experience an improvement within days, although it can occasionally take a month or more.
If you have a health problem, email drmarkporter@thetimes.co.uk