Jennifer Garner is embracing every precious year of life.

In this week’s issue of PEOPLE, the 51-year-old actress and longtime Neutrogena brand ambassadoradmits that even though she has her “moments” where she reflects on her younger years, “Honestly, mostly, I am grateful just to be alive.”

“And I’m grateful for the wisdom that I’ve gleaned out of these years and really grateful to be able to watch other women go through this process of life so gracefully,” Garner adds.

She also says she tries “to follow in their footsteps and tell other young women, ‘Take care of yourself, but don’t be scared. Aging is a gift.’ “

Jennifer Garner on June 3, 2023, in Hollywood, California. EMMA MCINTYRE/WIREIMAGE

As for what her own personal self-care routine looks like, the 13 Going on 30 actress tells PEOPLE she works out “every day,” as “it’s super important for my mental health.”

“I eat really well. I just finished a big bowl of kale,” she continues. “And I have a really strong family and strong relationships in my life.”

The mother of three — who shares Violet, 18, Seraphina, 15, and Samuel, 12, with ex-husband Ben Affleck — says she also allows herself to “have down days.”

“I don’t try to be Pollyanna all the time,” Garner says. “And I’m gentle with myself.”

Jennifer Garner in Los Angeles on April 13, 2023. AMANDA EDWARDS/WIREIMAGE

Though she prioritizes her own health, for her upcoming birthday next month, Garner is prioritizing “look(ing) outside of” herself.

“Every year I do something that I love to include people in that feeds me,” says the Once Upon a Farm co-founder. “Last year I went to a park in L.A. and planted trees with my kids. One year we loaded backpacks up to give kids food to take home with them after school.”

“I know what I’m going to do this year, and it’s coming together,” adds the Family Switch actress. “To me that day is about: How am I going to look outside of myself? How am I giving back to the world that gives me so much?”