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China science

Bai fu mei: China’s obsession with white skin and ‘trophy’ partners may stem from genetic mutation 15,000 years ago, scientists say

New international study led by Chinese team finds the diverging complexions of Han Chinese and native Africans and Southeast Asians was caused by a mutation of the OCA2 gene 15,224 years ago

PUBLISHED : Tuesday, 12 January, 2016, 2:14pm
UPDATED : Monday, 12 June, 2017, 12:53pm

Chinese people’s preference for paler or white-coloured skin originates from a “defective” gene, according to an international study led by Chinese scientists.

Men in the country can often seem obsessed with fair skin, especially in a partner, while many women have in the past favoured a Caucasian or “trophy” husband. This has long been dismissed as a social, economic or cultural problem, but new evidence suggests it may stem from a genetic predisposition.

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For thousands of years, China was ruled by pale-looking nobles in the north, and the invasion of Europeans in its more modern history further added to the perception that a white skin colouring was somehow superior.

But the new study found that the phenomenon could have a biological explanation dating back to prehistoric times as the relatively light skin colouring of the Han Chinese may derive from the same gene held responsible for a number of diseases.

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The researchers from China, the United States and Europe analysed genetic samples from more than 1,000 individuals and found that the fairer skin of the Han Chinese in comparison to people from Africa and Southeast Asia was caused by a mutation of the OCA2 gene.

One of the gene’s main functions is to help transport tyrosine, an amino acid used as a raw material in synthesising melanin, a pigment that determines skin colouration .

The mutated version of the gene has been linked to many diseases, such as albinism, acute eye inflammation, Angelman syndrome (characterised by mental disability and jerky movements), learning difficulties and obsessive eating, to name but a few.

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The team of researchers were led by Professor Su Bing at the Kunming Institute of Zoology in Yunnan province, and Meng Anming from Tsinghua University in Beijing.

They estimated that the mutated genes which led to the fairer skin of the Han Chinese occurred some 15,224 years ago. This happened after that group’s ancestors migrated up north from Southwest China and Southeast Asia about 25,000 – 30,000 years ago.

The first pale-skinned people may have been mistaken for sickly individuals by other members of their clan or tribe, who were predominantly dark-skinned.

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This dark colouring would have served as a natural form of defence “against the harmful effects of UV radiation, including protection against sunburn and folate destruction”, according to the team’s paper published in the latest issue of the journal Molecular Biology and Evolution.

But in north China, which experiences less sunshine than other parts of the country, the whiter skin allowed the body to absorb more sunlight to prevent a deficiency of vitamin D. A shortage of this can lead to fragile or brittle bones, cardiovascular problems and cognitive impairments.

According to the laws of natural selection, those with lighter skin were fitter for survival in the new environment. They may also have enjoyed other physical advantages such as being taller with stronger bones and perhaps a greater intelligence, studies show.

Another interesting discovery of the latest study was that the same OCA2 mutation was not detected among Europeans, who also underwent a shift to paler skin after the first modern humans moved out of Africa.

But the evolution of people’s skin colour in Europe took place on a completely different set of genes such as SLC24A5 and SLC45A2, according to other studies.

The genetic difference between Han Chinese and Europeans implied “independent skin-lightening in both East Asians and Europeans”, the scientists said.

But they said other environmental and biological factors could not be ruled out, either.

“Dietary changes and/or sexual selection … may also have created selective pressure in skin lightening,” they wrote.

And that “selective pressure” has shown scant sign of easing up.

A quick pore through a Chinese search engine quickly reveals what many modern Chinese woman aspire to be: Bai-fu-mei. This portmanteau of three Chinese characters - “white”, “rich”, “beautiful” - puts white first, even though in today’s China, wealth is for many the most desirable quality.

A study by market research company Mintel last year found that more than 95 per cent of Chinese women aged 20 to 49 had used facial masks to whiten their face - or three times as many as in Britain.