The 39-year-old, who raises two kids with Coldplay frontman Chris Martin, said coming to know about her father's cancer was a big shock to her and her family, reported People magazine.
"When my father was diagnosed with cancer, it really changed the way that I lived - it changed my whole lifestyle. I completely changed my diet, and I got very serious about exercising and about exposure to toxins.
"It really changed the way that I thought. I think I had more of a laissez-faire attitude about my health, and when he got cancer it was a real shock. It was sort of like the break of my adolescence," she said.