For years, Princess Yasmin Aga Khan had known that something was desperately wrong with her mother, actress Rita Hayworth. In 1981, doctors gave a name—Alzheimer's—to the Hollywood legend's memory loss and sudden rages, but they couldn't help her daughter slow the disease's steady progression.

"At first I felt a sense of relief—here was a medical explanation," Khan says. "But now what?" Khan, whose father was the wealthy Prince Aly Khan, abandoned a singing career to become her mother's sole caretaker in the final years of her illness. She also threw herself into the search for a cure, joining the nascent Alzheimer's Association, lobbying Congress for increased federal funding, and, in 1984, holding the first Rita Hayworth fundraising gala. In 2004, her two annual fundraisers in New York and Chicago generated $3 million in donations.

"I always have hope, and we are making progress," says Khan, who is now honorary vice-chairman of the Alzheimer's Association in the U.S. and president of the UK-based umbrella organization Alzheimer's Disease International. "I don't know if a cure will be found in my lifetime, but I will be involved for my life. It's my mission."

*The name of this award was originally the Impact Award. In 2008, the awards were renamed as the Inspire Awards.