Yacon leaf (Smallantus sonchifolius) is an herb that has become popular in recent years due to a few controlled medical studies showing the positive effects of yacon leaf on diabetic rats. The herb is used in South America to control blood sugar. Some commercial green superfood formula makers list yacon leaf as an ingredient. Yacon is considered a superfood because it it high in flavanoids, fructooligosaccharides, and antioxidants. The interest in yacon leaf motivated a team of researchers in 2011 to study the long-term effects of yacon leaf extract. They experimented with yacon leaf tea on diabetic rats for ninety days. The results were that long-term usage of yacon leaf caused kidney damage in the rats. Yacon leaf is no longer being considered as a possible therapy for diabetes. Read more...