The Shakespeare in Love star's filmmaker father Bruce Paltrow died ten years ago after a bout with oral cancer, just weeks after his daughter's 30th birthday.
At the Stand Up to Cancer telethon broadcast on Friday (September 7), Paltrow told People: "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.
"This is my one life, and I need to invest in myself and my family and make sure that we can do what we can to stay healthy."
Paltrow served as executive producer for the event, which included appearances from celebrities like Alicia Keys, Emma Watson, Robert Pattinson and Coldplay.
"It's emotional for me because I keep getting emails from my mother saying how proud she is of me that I'm doing it, and she keeps talking about my father," Paltrow added.
"It's emotional to be in front of the cameras and encouraging people to join the fight against cancer. Especially when you're doing it in memory of someone that you loved so much."