Women more likely to have blonde hair than men, new study suggests

Scientists discovered 124 genes play a major role in determining hair colour

(Getty Images/iStockphoto)

The largest ever study into genes and hair colour has discovered that women are more likely to have blonde hair than men.

In a bid to understand the genetic roots of hair colour, scientists analysed data from 300,000 people who gave DNA samples to UK Biobank, 23andMe and the International Visible Trait Genetics Consortium.

They focused solely on people of European descent because their hair colour is more variable than African, Asian or Native American hair, which is typically black.

The international scientific team found a total of 124 genes that play a major role in determining human hair colour and, unexpectedly, discovered that women were twice as likely to be naturally blonde than men.

In comparison, they also revealed that men were three times as likely as women to have black hair.

“It's a mystery and it's intriguing because it wasn't what we were looking for,” Prof Tim Spector, joint lead author, from Kings College London, told the BBC.

“We thought it was a bias but it wouldn't go away and it's found in every sub-group of every population we saw.”

Study authors say they are unsure as to why there are so many more blonde women than men but that the data opens up a whole new area of research which should be explored.

“We thought it might have something to do with the attraction of women for darker skinned men and vice versa - but we don't think the genes are any different,” Spector explained.

“We think the genes are being expressed differently - so for some reason the blonde genes that may be there at birth are persisting in females and disappearing in males.”

Interestingly, scientists also say that their findings, which are published in Nature Genetics, could boost treatments for a number of different diseases.

As the largest ever study on pigmentation, they believe that the data will help to improve understanding of diseases like skin, testicular, prostate and ovarian cancers, as well as a person’s chances of having Crohn’s and other forms of bowel disease.