News tagged with caffeine

Related topics: food and drug administration

Researchers abuzz over caffeine as cancer-cell killer

(Medical Xpress)—Researchers from the University of Alberta are abuzz after using fruit flies to find new ways of taking advantage of caffeine's lethal effects on cancer cells—results that could one day ...

Apr 18, 2013
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Coffee drinking tied to lower risk of suicide

Drinking several cups of coffee daily appears to reduce the risk of suicide in men and women by about 50 percent, according to a new study by researchers at the Harvard School of Public Health (HSPH). The st ...

Jul 25, 2013
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Caffeine improves recognition of positive words

Caffeine perks up most coffee-lovers, but a new study shows a small dose of caffeine also increases their speed and accuracy for recognizing words with positive connotation. The research published November 7 in the open access ...

Nov 07, 2012
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Does caffeine enhance performance?

Unlike many drugs, caffeine may be taken legally by people of all ages, which helps make it the world's most widely used stimulant.

Jan 10, 2014
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Caffeine

Caffeine is a bitter, white crystalline xanthine alkaloid that is a psychoactive stimulant drug. Caffeine was discovered by a German chemist, Friedrich Ferdinand Runge, in 1819. He coined the term "kaffein", a chemical compound in coffee, which in English became caffeine. Caffeine is also part of the chemical mixtures and insoluble complexes guaranine found in guarana, mateine found in mate, and theine found in tea; all of which contain additional alkaloids such as the cardiac stimulants theophylline and theobromine, and often other chemicals such as polyphenols which can form insoluble complexes with caffeine.

Caffeine is found in varying quantities in the beans, 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 cherries 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, and the Yaupon Holly.

In humans, caffeine is a central nervous system (CNS) stimulant, having the effect of temporarily warding off drowsiness and restoring alertness. Beverages containing caffeine, such as coffee, tea, soft drinks, and energy drinks enjoy great popularity. Caffeine is the world's most widely consumed psychoactive substance, but unlike many other psychoactive substances it is legal and unregulated in nearly all jurisdictions. In North America, 90% of adults consume caffeine daily. The U.S. Food and Drug Administration lists caffeine as a "Multiple Purpose Generally Recognized as Safe Food Substance".

Caffeine has diuretic properties, at least when administered in sufficient doses to subjects who do not have a tolerance for it. Regular users, however, develop a strong tolerance to this effect, and studies have generally failed to support the common notion that ordinary consumption of caffeinated beverages contributes significantly to dehydration.

This text uses material from Wikipedia licensed under CC BY-SA