Caffeine
hideCaffeine 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.
For more information about Caffeine, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with caffeine
Caffeine reverses memory impairment in Alzheimer's mice
Jul 06, 2009 |
5 / 5 (9) |
3
Coffee drinkers may have another reason to pour that extra cup. When aged mice bred to develop symptoms of Alzheimer's disease were given caffeine - the equivalent of five cups of coffee a day - their memory ...
Caffeine doesn't reverse the negative cognitive impact of alcohol, study shows
Medicine & Health / Psychology & Psychiatry
Dec 07, 2009 |
5 / 5 (1) |
2
People who drink may want to know that coffee won't sober them up, according to new laboratory research. Instead, a cup of coffee may make it harder for people to realize they're drunk.
Bad news for coffee drinkers who get headaches
Aug 14, 2009 |
not rated yet |
2
High caffeine consumption, more headaches?
Your brain on -- and off -- caffeine
May 01, 2009 |
3.7 / 5 (14) |
9
Ever miss your daily cup of coffee and subsequently get a pounding headache? According to reports from consumers of coffee and other caffeinated products, caffeine withdrawal is often characterized by a headache, ...
A little java makes it easier to jive, researcher says
Mar 30, 2009 |
4.7 / 5 (7) |
5
(PhysOrg.com) -- Stopping to smell the coffee - and enjoy a cup of it - before your morning workout might do more than just get your juices flowing. It might keep you going for reasons you haven’t even considered.
High caffeine intake linked to hallucination proneness
Jan 14, 2009 |
3.5 / 5 (4) |
5
High caffeine consumption could be linked to a greater tendency to hallucinate, a new research study suggests.
A low dose of caffeine when pregnant may damage the heart of offspring for a lifetime
Dec 16, 2008 |
4.3 / 5 (18) |
3
A new study published online in The FASEB Journal shows that the equivalent of one dose of caffeine (just two cups of coffee) ingested during pregnancy may be enough to affect fetal heart development and then reduce heart ...
Consuming small amounts of caffeine when pregnant may affect the growth of an unborn child
Nov 03, 2008 |
4.1 / 5 (7) |
0
Consuming caffeine at any time during pregnancy is associated with an increased risk of fetal growth restriction (low birth weight), according to research published on bmj.com today.
Caffeine experts call for warning labels for energy drinks
Sep 24, 2008 |
3.7 / 5 (40) |
7
Johns Hopkins scientists who have spent decades researching the effects of caffeine report that a slew of caffeinated energy drinks now on the market should carry prominent labels that note caffeine doses and warn of potential ...
Java gives caffeine-naive a boost, too
Aug 26, 2008 |
3.3 / 5 (9) |
0
New research from the University of Alberta in Edmonton, Canada, shows that—for women—the caffeine advantage is indeed everything it's cracked up to be. Females who don't drink coffee can get just as much of a caffeine boost ...
Wake up and smell the coffee: Study finds that caffeine may help prevent MS
Jun 30, 2008 |
4.2 / 5 (14) |
1
A good cup of coffee might be just the wake-up call scientists need to stop multiple sclerosis.
Java and nighttime jobs don't mix: study
Nov 03, 2009 |
5 / 5 (1) |
0
Night-shift workers should avoid drinking coffee if they wish to improve their sleep, according to research published in the journal Sleep Medicine. A new study led by Julie Carrier, a Université de Montréal psycho ...
High caffeine intake can lead to arrhythmias
Aug 31, 2009 |
4 / 5 (1) |
1
Coffee is routinely consumed in countries within the Mediterranean basin. Coffee, an infusion of ground, roasted coffee beans, is the most widely consumed behaviourally active substance in the world. It contains ...
New study aims to reduce risk of childhood leukemia
Jan 26, 2009 |
4 / 5 (1) |
0
A study led by Dr Marcus Cooke at the University of Leicester and funded by World Cancer Research Fund (WCRF) UK is looking at whether consuming caffeine during pregnancy might affect the unborn baby's risk of developing ...
Study examines association between caffeine consumption and breast cancer risk
Oct 13, 2008 |
4 / 5 (2) |
0
Caffeine consumption does not appear to be associated with overall breast cancer risk, according to a report in the October 13 issue of Archives of Internal Medicine. However, there is a possibility of increased risk for wo ...
