Betel nut, the seed of the betel palm, is prepared with other substances as a mixture for chewing. It is similar to chewing gum. More than 200 million people in areas of the western Pacific and parts of Africa and Asia chew or suck on betel nut for its mild stimulant effects. Its effects in some ways resemble those of nicotine. Others use it as a part of social customs, much as people in the West use alcohol. Regular use can damage the mouth, gums, and esophagus, stain the teeth red, and can cause physical dependence.

Betel nut is mentioned in ancient Greek, Sanskrit, and Chinese texts from more than a century B.C.E. Later it became an important aspect of the economy and social life in India, Malaysia, the Philippines, and New Guinea. Betel was probably brought to Europe by Marco Polo, around 1300, and became an important item in trade.