"I am determined to do whatever I can," she said after receiving a standing ovation during a gala fundraiser in her honor at the Beverly Wilshire Hotel, the L.A. Times reported Sunday.
She told the crowd, which included Michael J. Fox, Harrison Ford and James Taylor, that Alzheimer's had taken her husband "to a distant place where I can no longer reach him." She said stem cell research held hope for a cure.
"We have lost so much time. I just can't bear to lose any more," she said.
Saturday's event marked the first time she had spoken publicly in favor of the research.
Fox, who has Parkinson's disease, said the former first lady's strong support of stem cell research would be a "tremendous boon."