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
North-West University Botanical Garden rockery. Some more common plant genera represented in the garden include Acacia, Aloe, Bonatea, Crinum, Dierama, Encephalartos, Eucomis, Eulophia, Euphorbia, Gasteria, Gladiolus, Haworthia, Hypoxis, Indigofera, Kniphofia, Plectranthus, Podocarpus, Polygala, Scadoxus, Searsia, Stapelia and Zantedeschia. In the tropical greenhouse a variety of tropical and subtropical plants from all over the world can be found. Some of the plants include a variety of food and medicinal plants including "Coffea arabica" (coffee), "Camellia sinensis" (tea), "Vanilla planifolia" (vanilla), "Saccharum officinarum" (sugarcane), "Cinnamomum zeylanicum" (cinnamon), "Oryza sativa" (rice), "Theobroma cacao" (cacao), "Siphonochilus aethiopicus" (wild ginger), "Warburghia salutaris" (pepper bark tree) and "Piper nigrum" (pepper).