YERBA MATÉ Yerba maté (Ilex paraguariensis), also known as maté, terere, and chimarrão, contains large amounts of caffeine detrimental for PKD. Caffeine inhibits the breakdown of cyclic AMP, resulting in ↑ cAMP, creating more cysts— ↑ symptoms & PKD size. Some have experienced ill effects after taking caffeine: migraine headaches, rise in blood pressure, kidney pain, kidney stones, ↑ cystic organ size. Chronic ingestion of yerba maté has been associated with esophageal and other cancers.