Science

Grey hair cannot be cured (yet)

Despite media claims we’re still a long way off from curing grey hair

By Maria Mellor

Hair. Most of us have it somewhere on our body, be it straight or curly, long or short, blonde, red or brown. There are approximately 100,000 hairs on the human head, and hundreds of thousands more all over the rest of your body, except for the palms of your hands, the soles of your feet and your lips. It’s part of the system that regulates the body’s temperature and can be used to indicate social status, health and fertility. “Humans are very distinctive among our primate cousins in that our scalp hair can be very luxuriant and long,” says Desmond Tobin, director of the Centre for Skin Sciences at the University of Bradford.

What do we really know about what causes different kinds of hair types? Some characteristics are passed down from our parents. This is the case with colour, aside from dyed hair obviously, and texture, whether it’s straight or curly. Our hair can change colour during our life as blonde children turn brunette before they hit puberty, and we all go grey as we get old. Some people are hairier than others, with bushier beards or monobrows, or have hair that strand by strand is thicker or thinner.

Genes affect the amount of pigment in the hair to determine the colour. There are two types of pigment that determine hair colour, eumelanin and pheomelanin. More eumelanin means hair is darker, while more pheomelanin makes hair more red. Grey hair then occurs when pigment is depleted. We know that the categories of hair colour (brown, blonde and red) depend on whether the gene is recessive or not. For example, red hair is a recessive gene, meaning that both parents have to pass down the gene to their child in order for them to have red hair. It’s all in our genes and finally scientists have identified markers that determine how a person’s hair looks.

Ten different genetic variants were recognised in the study, which could possibly lead to benefit research in the study of evolution as well as health and beauty.

Researchers from University College London looked at a sample of over 6,000 people living in Brazil, Colombia, Chile, Mexico and Peru, with participants being of European, African and Native American descent. The people were categorised by the colour, shape and pattern both on their scalp and faces, and recorded the genetic codes. They found the markers such as a variant of FOXL2 that linked to eyebrow thickness; and a PAX3 variant that is associated with monobrows. The markers that the media got most excited about was the one responsible for grey hair. According to the study, melanin’s production and storage is regulated by a process involving IRF4, and grey hairs appear when melanin production stops.

Professor Andres Ruiz-Linares, from University College London, said: “We have found the first genetic association to hair greying, which could provide a good model to understand aspects of the biology of human ageing.

“Understanding the mechanism of the IRF4 greying association could also be relevant for developing ways to delay hair greying.”

The Telegraph took this information and claimed that “end of grey hair in sight as scientists find gene responsible.” The finding of the genetic markers has been sensationalised and spun in this way in a multitude of different newspapers and blogs. This is probably not going to happen in the near future, unless you count ‘the near future’ as being a really, really long way off. Although they were found, we don’t actually know how they influence the characteristics of hair or how we can change them. The NHS website is keen to point out that “though many DNA variations may be associated with a trait, they don’t always have a direct effect on gene activity. As such, each individual study is unlikely to provide the whole answer.”

Nevertheless there are hopes that these findings could be used to create a better and more reliable picture in DNA profiling. Instead of having artist’s impressions of suspect based on eyewitness accounts, perhaps law enforcement would be able to build up a mugshot of sorts based on their genetic markers. However, more research needs to be done for this to happen. Manfred Kayser at Erasmus University Medical Center in Rotterdam confirms this, stating that “with the exception of hair colour, we don’t yet understand nearly enough of the genetic basis of these traits for them to be useful.”

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