Health effects of chocolate no medical or regulatory authority has approved any health claim. "Theobroma cacao", the cacao tree, produces seeds containing flavanols. The seeds have been used to make beverages for some 2000 years in Aztec, Olmec, and Maya civilizations in central and south America. The drinks were ascribed a wide variety of curative and stimulant properties, unsupported by experimental evidence. In the 19th century, chocolate as a solid was invented, and milk and sugar were added to create milk chocolate, high in fat and sugar. Doubtful research, sometimes funded by the chocolate industry, has at times made suggestions of possible health benefits
Black drink theorized to be black drink rituals, including what some anthropologists have interpreted as vomit issuing from the mouths of mythological beings. Pottery samples recovered from sites in modern Southwestern United States and Northwestern Mexico have tested positive for the ratio of methylxanthines associated with those produced by "Ilex vomitoria". The same study also identified methylxanthines ratios associated with "Theobroma cacao". Neither plants are native to the areas from which the pottery samples were recovered, which suggests trading between areas where those plants are native. The chemical analysis also suggests a possible increase in drinks prepared from cacao after the year