Does yerba mate cause cancer? Yerba Mate has unduly been implicated in causing cancer, mostly from a 2009 article published in LA Times (reference in link below). All the recent scientific studies investigating the relationship between yerba mate and cancer agree that there is not evidence to support any claims that yerba mate causes cancer. The principal risk is related to “very hot water” consumption, not the actual medium (tea, coffee, yerba mate). Read more here: Yerba Mate and Cancer Research.