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
Theobroma cacao was still suitable, and so provided a refugium for the species. Cacao trees grow well as understory plants in humid forest ecosystems. This is equally true of abandoned cultivated trees, making it difficult to distinguish truly wild trees from those whose parents may originally have been cultivated. Cultivation, use, and cultural elaboration of cacao were early and extensive in Mesoamerica. Ceramic vessels with residues from the preparation of cacao beverages have been found at archaeological sites dating back to the Early Formative (1900–900 BC) period. For example, one such vessel found at an Olmec archaeological site on the Gulf Coast