If You Think 40 Is Old, Cameron Diaz Would Like A Word With You

Age is nothing but a number... to some people. To others, it's the official way to designate individuals as "old" and, therefore, dismiss them as less valuable in society.

This is a perspective that actress Cameron Diaz has experienced first-hand -- and she is so over it.

Diaz, who is turning 44 this summer, has made it part of her mission to empower and embolden women of all ages. In addition to writing a new book on the science of living well, called The Longevity Book, she has also spoken candidly on the topic of aging. One of Diaz's recent stops was OWN's offices in Los Angeles, where she didn't hold back in sharing how she typically responds when confronted with ageism.

"Just because we're getting older doesn't mean we're not valuable anymore," Diaz begins. "To be told at 44 that I'm no longer valuable or that I'm not viable or that I'm just going to be discarded and nobody's going to care, there's a few things that happen."

Cameron's first response is nonverbal:

Then, Diaz says, she acknowledges the sting of such a sentiment and channels that energy into a response that empowers.

"I have another 40 years in me, at least. Why am I all of a sudden going to be afraid to live the rest of my life because I'm not 25?" Diaz poses. "It's up to me to embrace that. It's up to me to say, 'No, you don't get to say that to me.'"

Diaz knows she's not alone in feeling dismissed due to her age, and adds that it's within our power to spur change together.

"There's over 30 million women in the United States between the ages of 35 and 50. That's a lot of voices, that's a lot of opinions, that's a lot of power," she points out. "It's up to us to change the conversation. It's up to us to say, 'No, no, no, no, society, all you people looking in. You got it wrong. It's awesome in here.'"

With so many women facing ageism, Diaz says the entire conversation about aging can shift if we can all adopt a rousing new perspective.

"I'm going to do the best work I've ever done. I'm going to live better than I've ever lived. I'm going to love better than I've ever loved. And you're going to value me more than you ever valued me at 25," she says. "That's the perspective that we need to have."

Not only can this outlook spark a much-needed shift in our culture, but Diaz says it can also have a real, biological impact on each person individually.

"There is actual data ... that says that for people who accept aging and accept that you can age well and live well all the way up to your ripe old age, [they] actually live longer. In fact, 7 and a half years longer," she says. "That's a significant amount of time."

Diaz explores more data and expert opinions in The Longevity Book, available on harpercollins.com.

Also: Diaz shares her five-minute workout routine