Jamie Lee Curtis has celebrated her 50th birthday by posing topless.

The actress appears on May’s cover of the American Association of Retired Persons mag grey-haired and wading through a swimming pool, which she says reflects her new understanding of beauty.

She explains, “I want to be older. I actually think there's an incredible amount of self-knowledge that comes with getting older.

“I feel way better now than I did when I was 20. I'm stronger, I'm smarter in every way.”

However, Curtis - who secured a permanent place in countless adolescent nocturnal memory banks by shedding her top in eighties comedy Trading Places - reveals she’s managed to drop nearly two stones since she staged a similar stunt in 2002 for More Magazine, when she appeared without make-up in only her bra and panties.

“I started a really healthy way of eating, just avoiding things that I had been shoving in my mouth. Over the course of a year, I dropped about 20lb,” she says.

"Now, I get up every day filled with energy. I play tennis three times a week, and I do yoga."