A 90-year-old woman from Urumqi has revealed the secret to keeping her hair silky and black well into later life, and it turns out to be egg soup.

Ai Lan, who lives in the city's Midong district, claims that by drinking egg soup three times a day she is able to ward off those pesky grey and white hairs so synonymous with old age.

"My mother has drunk egg soup every day for 20 years," says Chen Xiying, Ai's daughter.

Ai Lan, a 90-year-old woman from Urumqi reads a newspaper. Despite her old age, Ai hasn't a single thread of white hair. [Photo/iyaxin.com]

The recipe couldn't be simpler.

"I hold an egg in each hand," says Ai. "Knock them together and put the egg white and yolk in a small bowl. I then add boiling water and stir; the egg soup is done!"

Ai eats six eggs a day, that's twice amount recommended by nutritionists.

So although it seems to have worked for Ai, most experts agree that it is not a good idea for the rest of us.

"Drinking uncooked egg whites is actually not good for health," says Fan Min, head of the nutrition research department of the Xinjiang People's Hospital. A close friend of Ai told the Morning Post newspaper in Xinjiang that the real reason for Ai's pure black hair was her relaxed attitude to life and avoiding stress.

"I think that it is because she is always at peace," He Juying told the Morning Post."I have never seen her arguing with others and she is always smiling."

Ai had a son when she was very young who passed away a long time ago, and though she has had many ups and downs in her life, she seldom mentions her troubles.

"She just loves to relax and read the newspaper, though nowadays she tends to just look at the pictures," says Cheng.

Ai said that she will continue her daily regimen of egg soup and hopes to continue to flash her black locks well into the future.

Edited by Owen Fishwick