The oldest woman alive, who lives on raw eggs and cookies, is celebrating her 117th birthday.

Emma Morano, who was born on 29 November, 1899, is believed to be the only person alive who has witnessed three centuries.

The brandy-drinking Italian woman, who has credited her old age to being single and getting to bed early, reportedly said “My word, I’m as old as the hills”, when she was crowned the world’s oldest.

Emma Morano, 116, is the oldest living person in the world OLIVIER MORIN/AFP/Getty (AFP)

“I eat two eggs a day, and that’s it. And cookies. But I do not eat much because I have no teeth,” she said, in an interview with AFP last month.

The supercentenarian says she started the habit of eating two raw eggs, and one cooked egg, every day, aged 20, when she was diagnosed with anaemia.

Ms Morano, who does not eat meat partly through fear of contracting cancer, has lived alone since she left her violent husband in 1938 shortly after the death in infancy of her only son.

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“I didn’t want to be dominated by anyone,” she said.

The former factory worker and cook, who took on a full-time carer and has been bedbound since last year, has not left her Verbania apartment on Lake Maggiore in 20 years.

She has outlived all her eight younger siblings and now proudly boasts the Guinness World Records certificate, declaring her the oldest person alive, on her marble-topped chest of drawers.

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“People come. I don’t invite anybody but they come. From America, Switzerland, Austria, Turin, Milan … They come from all over to see me,” she said.

She is not sure whether she will eat any birthday cake, adding: “The last time I ate a little, but then I did not feel good.”

Ms Morano is apparently alert, but is very deaf, speaks with difficulty and cannot see well enough to watch television.

Her physician, Carlo Bava, has branded Ms Morano’s longevity as a “phenomenon”.

On her birthday, journalists, relatives and the town mayor will visit, while a local theatre will perform music over three centuries and a dramatisation entitled: “The woman who saw three centuries”.