Editor's Note: In an American Morning original series, “Big Stars, Big Giving,” Alina Cho looks at celebrity philanthropy and how these big stars can make a big impact. Through one-on-one interviews with Elton John, Ben Stiller, Madonna, Martha Stewart and Richard Branson, she shares what causes have become their passion, and how you can get involved. In part four, Alina sits down with Martha Stewart to discuss her living center for older adults. Thursday, 6-9 a.m. ET – only on CNN.

And check out the rest of Alina's series on celebrity philanthropy, Big Stars, Big Giving.

To learn more about the organizations these stars have created to make a difference,

and how you can get involved, visit Impact Your World.