"You do try to hide it from everybody," Barbara Smith, 64, tells CBS News.
Smith, who was one of the first African American models to grace the cover of Mademoiselle before opening her own restaurant chain, told her doctor about her symptoms four years ago.
They have since become quite serious. In an interview with CBS, Smith didn't know the day, month or year. "Things like that make me very sad," she says.
Asked what her Alzheimer's diagnosis meant to her, she added, "It meant something bad – really bad to me."
Smith recently underwent a brain scan looking for amyloid, a protein that damages nerves and is evident in Alzheimer's patients. "It's everywhere," her doctor told CBS.
But Smith, as ever, remains hopeful and upbeat.
"I think the future's going to be fine," she says. "I'm going to do my best to make it work out for me, and for as many people that I can possibly help, too."