Meryl Streep said today she was proud to still be acting "on behalf of all the old broads".
The veteran star said she hoped the success of Mamma Mia would encourage studios to make films for an older female audience.
Women over 40 had been "disdained" by Hollywood boardrooms in the past, she said.
Streep, who will turn 60 in June, told the Radio Times that studios have been stuck in a rut of making movies to appeal to men and younger women who are dating.
"I think with the success of a few big pictures like Mamma Mia! addressing an audience that, never mind being neglected, have been disdained in the boardrooms, there will be other films that target that audience," she said.
"Mamma Mia! is that rare thing you can enjoy with your mother or your child, and its aim is only to make you happy."
The adaptation of the West End show based on Abba songs was last year's biggest box office hit in the UK, pulling in more than £69 million.
Streep said her daughters had helped her to stop worrying about her appearance over the years.
"I wasted so many years thinking I wasn't pretty enough and why didn't I have Jessica Lange's body or someone else's legs? What a waste of time," she told the magazine.
"Now I'm enjoying the tatters of what's left and I'm very happy. Part of it is having beautiful strong daughters and hearing them whine about what's wrong with them.
"I'm like, "Shut up! You're lovely!"
Actresses in earlier generations were written off as soon as they hit 40, Streep said.
"At 48 you were getting out the shovel ready to go in ... I'm out there on behalf of all the old broads and I'm proud to be there," she said.
:: The full interview appears in this week's Radio Times, on sale today.