What is the most damaging food?

A dietician was once addressing a large audience in Chicago. "The material we put into our stomachs is enough to have killed most of us sitting here, years ago. Red meat is awful. Vegetables can be disastrous, and none of us realizes the germs in our drinking water. But there is one thing that is the most dangerous of all and we all of us eat it. Can anyone here tell me what lethal product I'm referring to? You, sir, in the first row, please give us your idea."

The man lowered his head and said, "Wedding cake.