Well, if you're lucky enough to live as long as Mariam Ammash, there's still hope for you.

CNN's Ben Wedeman caught up with the self-proclaimed oldest human being on earth and sent us this report:

-- I recently turned 48 years old, and was wondering when I would start feeling (and acting) my age. But after meeting Mariam Ammash today in the Arab-Israeli town of Jisr Al-Zarqa, I realise I was wasting my time.

A few weeks ago she showed up at a government office in the town of Hadera to replace a lost identity card. And there they were stunned to discover her birth date.

She claims to be one hundred and twenty years old, born way back in 1888, at a time when this land was under the rule of the Ottoman Empire. She would have seen the Ottoman Turks driven out by the British in World War One, and the creation of Israel in 1948.

Is it for real? Honestly, it seems a bit of a stretch. For one thing, her oldest son, Hilmi, is eighty years old. Which means she would have given birth to him at the age of fourty. In traditional Arab society, a woman giving birth to her first child at that age was almost unheard of. And I met another son, Mohamed, who is fifty four years old. Mariam would have been 66 years old at the time. And frankly that is stretching the credulity a tad.

But whether she's that old or not, she's a woman who is holding up remarkably well. She lives on her own, walks all over her neighbourhood, checking up on her more than four hundred children, grandchildren, great-great-children, and so on. And it seemed as if everyone we spoke to in Jisr Al-Zarqa was related to Mariam in one form or another.

She told me the secret to her longevity was fresh fruit and vegetables, fish straight out of the sea and dairy products and meat from animals she had raised. She also recommends drinking a glass of unprocessed olive oil every morning, along with herb tea and homemade bread. And of course, she said, stay away from alcohol and tobacco.

So whether she's that old or not, it really doesn't matter. I'll try to follow her advice and see if I make it to 120, or maybe half that.

Watch Ben's report on Mariam Ammash here.