http://www.machupicchu-inca.com/acclimatization-at-peru.html
Cocoa tea
Banzai, are you sure you don't mean Mate de Coca tea? The website you provided says it is cocoa tea, but I believe that its authors are substituting "Cocoa" for "coca" in their translation to English. Here are some statements from a variety of articles:
Bolivia, the world's third biggest cocaine producer, should redesign its coat of arms to include coca leaves
The coca leaf can also be used to make tea, and as such provides many of the same medicinal qualities. The use of coca in its boxed tea form is more predominant in upper class Bolivian society. Among the rural population in Bolivia, it is estimated that that 60-80% of the population consumes coca in the traditional acullico form. That number increases to approximately 90% when other forms of usage, such as tea and medicinal preparations, are included.
Coca is a plant in the family Erythroxylaceae, native to north-western South America. The plant plays a significant role in traditional Andean culture. Coca leaves contain cocaine alkaloids, a basis for the drug cocaine, which is a powerful stimulant.
Coca should not be confused with the similarly named South American cocoa bean from which chocolate is made.
Coca tea, also called mate de coca, is a tisane (herbal tea) made using the leaves of the coca plant. It is made either by submerging the coca leaf or dipping a tea bag in hot water. The tea originates from the Andes mountain range, particularly Peru. The leaves of the coca plant contain several alkaloids including cocaine; in fact, they comprise the sources for cocaine's chemical production, though the amount of cocaine in the leaves is so small, around 0.2%