Soy foods are those which come from soybeans, a protein-rich legume. Isoflavones are chemical compounds found in soy that have a similar structure to the hormone estrogen. The controversy around soy comes from misinformation about isoflavones causing some individuals to avoid it. However, studies have shown soy to cause either a beneficial or neutral impact. People should eat in a way that suits them but note that soy consumption is not harmful to human health.