Angelina Jolie underwent her preventative double mastectomy in 2013 to ''improve [her] odds'' of seeing her children ''grow into adults''.

The 'Maleficent: Mistress of Evil' star - who has Maddox, 18, Pax, 15, Zahara, 14, Shiloh, 13, and 11-year-old twins Knox and Vivienne with her ex-husband Brad Pitt - had the preventative procedure after losing her mother to breast and ovarian cancer in 2007, and her aunt to the same disease in 2013, the same year she decided to go under the knife.

Now, Angelina - who also had her ovaries and fallopian tubes removed after an ovarian cancer scare in 2015 - has said her decision came as she wanted to make sure she could watch her children grow old, without fear of developing cancer.

In an emotional essay penned for Time magazine, she wrote: ''I simply feel I made choices to improve my odds of being here to see my children grow into adults, and of meeting my grandchildren. My hope is to give as many years as I can to their lives, and to be here for them.''

Angelina, 44, underwent a genetics test which showed she carried a mutated BRCA1 gene, predisposing her to the possibilities of developing breast cancer.

And the actress hopes her decision to combat the mutated gene early means she will be able to ''live a bit longer'' for the sake of her brood.

She added: ''I have lived over a decade now without a mum. She met only a few of her grandchildren and was often too sick to play with them. It's hard now for me to consider anything in this life divinely guided when I think of how much their lives would have benefited from time with her and the protection of her love and grace. My mother fought the disease for a decade and made it into her 50s. My grandmother died in her 40s. I'm hoping my choices allow me to live a bit longer.''

In her essay, the 'Lara Croft: Tomb Raider' star also spoke about the importance of mental health in cancer treatment.

She wrote: ''I have learned that when it comes to women's health, medical advances are only one part of the picture. Mental and emotional health, and physical safety, are just as important.

''I understand now that we often focus on the specific cancer or illness affecting a particular woman, but miss the bigger diagnosis: her family situation, her safety and whether she is carrying stress that is undermining her health and making her days much more difficult.''