Most modern chewing gums are made with synthetic rubbers, such as polyethylene and polyvinyl acetate.
Not only are these unnatural substances less than stellar for your health, they also tend to end up on the ground—resulting in more plastic making its way to the natural environment.
Finding the gum habit hard to kick? There are some natural chewing gums out there. Look for gums made with chicle, a supplement found in tree sap.