Sophia Loren Stuns on the Red Carpet at 78

She spent the majority of her showbiz career as an international sex symbol, and on Tuesday night, 78-year-old Sophia Loren proved that age is truly just a number when she showed off her trim figure in a low-cut curve-hugging dress. The Italian actress donned the white beaded gown with sheer long sleeves and a slit up the front when she hit the red carpet in Rio de Janeiro for the launch of the Italian tire maker Pirelli's annual calendar.

Though she stood alongside models 50 years her junior, the "A Countess From Hong Kong" star still came off looking pretty darn hot. The coveted calendar always features a gaggle of drop-dead gorgeous models and actresses. (Past publications have included beauties like Heidi Klum and Penelope Cruz.

This year, supermodels including Petra Nemcova and a pregnant Adriana Lima were featured. Though Loren wasn't part of the 2013 calendar, she did make an appearance back in 2007, when the then-72-year-old was photographed in a super sultry pose looking half her age.

So what's her secret? In her 1984 book Women & Beauty, Loren claims discipline is the key to looking good, calling it "the great equalizer." "If a young woman is beautiful but has no discipline, she will lose her looks as she grows older," Loren writes. "If a plain woman is disciplined she will undoubtedly become more beautiful with time."

And while the classic beauty has reportedly said she bathes in olive oil as part of her beauty regimen, in her book she attributes her smooth skin — and fit figure — to good genes. "I am lucky with my skin because it is what is termed 'normal'; that is, it is neither dry nor oily," she shares. "My weight has never been a problem for me. I have gained a few pounds for a time and then lost them again..."

And disciplined or not, if her weight isn't a problem now that she's 78, it probably never will be. See you in next year's calendar, Sophia?

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