The most dispiriting aspect of our belated environmental consciousness is the realization that many of the delightful substances we put into our mouths — like cold bottled water and imported produce — have costs that far outweigh the immediate gratification they deliver. In “Sugar: A Bittersweet History,” her thorough, workmanlike new study, Elizabeth Abbott reminds us that this has been true for centuries. A hundred years before Pushkin described ecstasy as “a glassful of tea and a piece of sugar in the mouth,” the demands of the sugar economy had ripped apart African communities and forced slaves across the Atlantic to work sugar cane plantations. Abbott’s book, which discusses the effects of sugar on everything from the Haitian revolution to Hitler’s Germany, serves as a grim reminder that a consumer’s choices register on a gigantic scale, and are therefore as much political as personal.