Why does hair turn grey as we grow older?
For some of us, the first grey hairs appeared in our youth, even as early as 15. At 30, about a quarter of the population has same tell-tale signs of the greying to come. Some 28 percent of us will eventually have hair that is completely white. A few fortunate people will get no grey hairs at all.
If your parents or grandparents went grey, chances are that you will do so at about the same age and in the same way. Caucasians have a 50/50 chance that half their hair will be grey or white at the age of 50. Blacks begin to turn noticeably grey about six years later than whites. in their early forties.
But why should hair turn grey or white instead of, say, bright blue?
Cells called melaconytes determine hair colour. By producing and mixing just two basic pigments, eumelanin and pheomelanin, these cells give human hair its wonderful range of colours. Eumelanin may tint each strand of hair any color from the deepest black to the lightest brown; pheomelanin may turn it blonde, golden or red. The volume, shape, brightness and density of the pigments in each individual mix give your hair its distinctive look.
If melaconytes become less active, as they do in our twenties, new hairs growing from the hair folicles carry less of their original pigmentation, and emerge grey. When the melaconyte cells cease work, which they may do naturally according to your genes or when influenced by trauma or disease, your hair will grow without pigment, in the basic colour of its protein--snow white. Sometimes because of the hair's normal colour, the growth of white hairs is hard to detect.
Redheads have some 90,000 hairs on their heads, brunettes about 108,000 and blondes 140,000. Half a blonde's hair could turn white before the overall effect was one of greyness. Scientists say that light-haired people are more likely to become completely grey.
Hair colour and quality, like complexion, is often a barometer of health. Severe trauma may prompt the growth of grey hair. And so may a range of diseases, such as influenza, diabetes, typhus, malaria, some forms of herpes and conditions such as malnutrition, hyperthyroidism and anemia. People exposed to some kinds of radiation, whether by accident or in therapy, may go grey or lose their hair.
Can hair turn white overnight? Well, not quite so swiftly, but quickly enough to cause considerable distress. A person may be afflicted by alopecia aerata, a disorder brought on often by stress. It may cause older, darker hairs to fall out in just a few days. If the victim already has a substantial scattering of grey or white hairs, the hair will indeed seem to have turned white overnight.
Can the grey-heads hope to see their hair regain its natural color? Indeed they can unless baldness robs them of the little they've got. recent research has found how to give hair new growth and even its original hues, when greyness results from disease. Anemia sufferers, for instance, who were given B12, found their hair gradually regaining its colour.
For some 40 percent of women and eight percent of men who now use dyes, new products may offer a chance to impregnate their hair with natural melanin, adjusted to almost any shade.
But who says that grey hair is a sign of old age? Every society has outstanding examples to prove the adage that you can have snow on the roof and a blazing fire in the furnace.