Yerba mate has significant antioxidant activity. In 2005, researchers at the University of Illinois at Champaign –Urbana analyzed 25 different kinds of yerba mate and found that mate contained higher levels of antioxidants than green tea and, and based on cellular studies, reported that there was a correlation between yerba mate’s polyphenol content, antioxidant capacity and human topoisomerase inhibition that may help prevent oral cancer.
Prior to this most recent research, researchers in 1995 published a study in Biochemical and Molecular Biology International in which they concluded that water extracts of yerba mate “were more potent antioxidants than either ascorbic acid (vitamin C) or butylated hydroxytoluene.” A few years later, a group of researchers embarked on a study to again investigate the antioxidant properties of Ilex paraguariensis infusions. Those findings were published in March of 2000 in the Journal Biochemical and Biophysica Research Communications. Their results suggest “that ingestion of extracts of Ilex paraguariensis could contribute to an increase in the antioxidant defense of an organism against free radicals attack.” In a more recent study, published in the November 2001 issue of Fitoterapia, researchers took a look at seven different plant species in South America. They found that yerba mate “contained a higher content of flavonoids and caffeoyl derivatives than any other assayed species.”