Cameron Diaz in Her Most Powerful Roll Yet: Scientist | #OWNSHOW | Oprah Online

As she approached her 40s, Cameron Diaz was faced with the same trying question most women face: Aren’t you afraid to be 40? Instead of living in fear, Diaz embraced her age and followed her love of science and the body, which led her to write The Longevity Book. Watch above as she explains the journey we take as we age and why it’s important to know what are our cells actually doing.