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
Madeira-Tapajós moist forests excelsa" and "Duckeodendron cestroides". At one time the endemic tree "Polygonanthus amazonicus" grew near Maués, the western limit for the emergent "Dinizia excelsa" and the eastern limit for the "Theobroma cacao". The Tapajós basin is the eastern limit of "Theobroma microcarpum". The "Physocalymma scaberrima" has red hardwood used by furniture makers. The montane forests of the upper Marmelos and middle Tapajós hold "Hevea camporum", "Euterpe longibracteata", "Huberodendron ingens" and "Brachynema ramiflorum". Further south in Mato Grosso there are forests in the transition between the Amazon and cerrado biomes. 183 species of mammals have been reported, including 90 bat species and