Smith, 64, began her career as a model and was one of the first African Americans to grace the cover of Mademoiselle. In 1986, she opened her first restaurant in New York City, and two more followed. (Her Washington eatery closed last year after 20 years in business.) She went on to become a pioneer in the lifestyle area, an expert in food and home entertaining.
Around four years ago, Smith noticed that she was repeating herself and forgetting things. She shared her symptoms with her doctor before she told her husband and business partner of 22 years, Dan Gasby, CBS reports.
In October, a brain scan revealed that her symptoms had progressed.
While she says she is "sad," she continues to be positive.
"I think the future's going to be fine," Smith 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."
CBS will air more of its Smith interview June 15 on CBS Sunday Morning.