Nowadays, teeth whitening is all the rage, but check out this article from Grunge.com to find out why blackened teeth were once desired instead!
The consumption of sugar has been a ubiquitous part of life for centuries, with modern countries importing record amounts of it. In ancient India (the origin of sugar cultivation), Greece, and Rome, sugar was treated as a medicine for various ailments (via Czarnikow). They did not know the consequences of a sugar-laden diet, however, as honey and lead were typically their sweeteners of choice (via Smithsonian Magazine). Even as sugar cane cultivation and culinary use spread from India to China, the Middle East, and Europe, it remained an expensive additive and its rare use was indicative of wealth.
European discovery of the Americas changed this, as the Caribbean environment was perfect for massive sugar cane plantations (which was, in turn, a driving force for Native and African enslavement). As sugar production increased dramatically, so too did its demand from Europe's wealthy. Now it was not only one's ability to buy sugar that was a symbol of status but how much one could buy. Where the Romans (unknowingly) exchanged lead-poisoning for good dental health, 16th century England, in particular, would take sugar in the opposite direction with a disgusting method of displaying wealth (via CNN).