Caffeine, sometimes called theine when found in tea, is a xanthine alkaloid found in the leaves and beans of the coffee tree, in tea, yerba mate, guarana berries, and in small quantities in cocoa, the kola nut and the Yaupon holly.
In plants, caffeine acts as a natural pesticide that paralyzes and kills many insects feeding upon them.
Caffeine is a central nervous system (CNS) stimulant, having the effect of warding off drowsiness and restoring alertness.
Caffeine-containing beverages, such as coffee and tea, enjoy great popularity, making caffeine the world's most popular psychoactive substance.
For more information about the topic Caffeine, read the full article at Wikipedia.org, or see the following related articles:
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.
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