Chewing gum
Chewing gum is a type of gum traditionally made of chicle
Manilkara chicle is a tropical evergreen tree native to Mexico and Central America. The tree ranges from Veracruz in Mexico south to Atlántico in Colombia...

, a natural latex
Latex is the stable dispersion of polymer microparticles in an aqueous medium. Latexes may be natural or synthetic.Latex as found in nature is a milky fluid found in 10% of all flowering plants . It is a complex emulsion consisting of proteins, alkaloids, starches, sugars, oils, tannins, resins,...

 product, or synthetic rubber
Synthetic rubber
Synthetic rubber is is any type of artificial elastomer, invariably a polymer. An elastomer is a material with the mechanical property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation...

 known as polyisobutylene. For economical and quality reasons, many modern chewing gums use rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

 instead of chicle. Chicle is nonetheless still the base of choice for some regional markets, such as Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

Chewing gum in various forms has existed since at least 5,000 years ago at minimum the Neolithic period
The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age...

. 5,000-year-old chewing gum with tooth imprints, made of birch bark
Birch bark
Birch bark or birchbark is the bark of several Eurasian and North American birch trees of the genus Betula.The strong and water-resistant cardboard-like bark can be easily cut, bent, and sewn, which made it a valuable building, crafting, and writing material, since pre-historic times...

 tar, has been found in Kierikki, Yli-Ii
Yli-Ii is a municipality of Finland.It is located in the province of Oulu and is part of the Northern Ostrobothnia region. The municipality has a population of and covers an area of of which is water...

, Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...