A friend is citing a faculty resource page from Colorado State, and saying the claims are therefore legitimate. But surely precolumbian drug trade would've made the history books, can /askhistorians shed some light on how accepted this claim is? $50 is on the line..
/u/RioAbajo addressed this recently here: Was there tobacco in Eurasia before the Columbian Exchange?
/u/Reedstilt makes a comment here: Did trans-oceanic trade occur before the discovery of America?