Caffeine

Caffeine

About Caffeine

Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants. It is most commonly consumed by humans in infusions extracted from the seed of the coffee plant and the leaves of the tea bush, as well as from various foods and drinks containing products derived from the kola nut. Other sources include yerba mate, guarana berries, guayusa, and the yaupon holly. In humans, caffeine acts as a central nervous system stimulant, temporarily warding off drowsiness and restoring alertness. It is the world's most widely consumed psychoactive drug, but, unlike many other psychoactive substances, it is both legal and unregulated in nearly all parts of the world. Beverages containing caffeine, such as coffee, tea, soft drinks, and energy drinks, enjoy great popularity; in North America, 90% of adults consume caffeine daily. Caffeine is toxic at sufficiently high doses. Ordinary consumption can have low health risks, even when carried on for years there may be a modest protective role, part of which is to reduce neural activity levels – for example, there is some evidence that adenosine helps to induce torpor in animals that seasonally hibernate.

Contributions by Ryguillian, Jfdwolff, and Mkweise.