Chewing gum has been around for hundreds of years in the form of chicle, a resin obtained from the sapodilla tree in southern Mexico and Central America.

Long ago, the Mayans and the Aztecs knew that by cutting the bark, they could collect this resin and create a chewable substance from it. The Mayans cooked and dried it into "cha" to quench thirst and prevent hunger. The Aztecs used it as a breath freshener but viewed public gum chewing as unacceptable.

By the mid-1930s, unsustainable harvesting methods used to increase yields killed almost a quarter of Mexico's sapodilla trees, and scientists predicted total forest depletion within four decades.

Chewing gum manufacturers turned to cheaper synthetic bases made from petroleum, wax and othe...