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 non-herbal 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.
Occurrence
![]()
Caffeine is found in many plant species, where it acts as a natural pesticide, with high caffeine levels being reported in seedlings that are still developing foliages, but are lacking mechanical protection; caffeine paralyzes and kills certain insects feeding upon the plant. High caffeine levels have also been found in the surrounding soil of coffee bean seedlings. It is therefore understood that caffeine has a natural function as both a natural pesticide and as an inhibitor of seed germination of other nearby coffee seedlings thus giving it a better chance of survival.
The most commonly used sources of caffeine are coffee, tea, and to a lesser extent cacao. Less commonly used sources of caffeine include the yerba maté and guarana plants, which are sometimes used in the preparation of teas and energy drinks. Two of caffeine's alternative names, mateine and guaranine , are derived from the names of these plants. Some yerba mate enthusiasts assert that mateine is a stereoisomer of caffeine, which would make it a different substance altogether. This is not true because caffeine is an achiral molecule, and therefore has no enantiomers; nor does it have other stereoisomers. The disparity in experience and effects between the various natural caffeine sources could be due to the fact that plant sources of caffeine also contain widely varying mixtures of other xanthine alkaloids, including the cardiac stimulants theophylline and theobromine and other substances such as polyphenols which can form insoluble complexes with caffeine.
One of the world's primary sources of caffeine is the coffee "bean" (which is the seed of the coffee plant), from which coffee is brewed. Caffeine content in coffee varies widely depending on the type of coffee bean and the method of preparation used; even beans within a given bush can show variations in concentration. In general, one serving of coffee ranges from 40 milligrams, for a single shot (30 milliliters) of arabica -variety espresso, to about 100 milligrams for a cup (120 milliliters) of drip coffee. Generally, dark-roast coffee has less caffeine than lighter roasts because the roasting process reduces the bean's caffeine content. Arabica coffee normally contains less caffeine than the robusta variety. Coffee also contains trace amounts of theophylline, but no theobromine.
Tea is another common source of caffeine. Although tea contains more caffeine than coffee, a typical serving contains much less, as tea is normally brewed much weaker. Besides strength of the brew, growing conditions, processing techniques and other variables also affect caffeine content. Certain types of tea may contain somewhat more caffeine than other teas. Tea contains small amounts of theobromine and slightly higher levels of theophylline than coffee. Preparation and many other factors have a significant impact on tea, and color is a very poor indicator of caffeine content. Teas like the pale Japanese green tea gyokuro, for example, contain far more caffeine than much darker teas like lapsang souchong, which has very little.
Caffeine is also a common ingredient of soft drinks such as cola, originally prepared from kola nuts. Soft drinks typically contain about 10 to 50 milligrams of caffeine per serving. By contrast, energy drinks such as Red Bull can start at 80 milligrams of caffeine per serving. The caffeine in these drinks either originates from the ingredients used or is an additive derived from the product of decaffeination or from chemical synthesis. Guarana, a prime ingredient of energy drinks, contains large amounts of caffeine with small amounts of theobromine and theophylline in a naturally occurring slow-release excipient.
Chocolate derived from cocoa contains a small amount of caffeine. The weak stimulant effect of chocolate may be due to a combination of theobromine and theophylline as well as caffeine. A typical 28-gram serving of a milk chocolate bar has about as much caffeine as a cup of decaffeinated coffee.
In recent years various manufacturers have begun putting caffeine into shower products such as shampoo and soap, claiming that caffeine can be absorbed through the skin. However, the effectiveness of such products has not been proven, and they are likely to have little stimulatory effect on the central nervous system because caffeine is not readily absorbed through the skin.
Various manufacturers market caffeine tablets, claiming that using caffeine of pharmaceutical quality improves mental alertness. These effects have been borne out by research that shows that caffeine use (whether in tablet form or not) results in decreased fatigue and increased attentiveness. These tablets are commonly used by students studying for their exams and by people who work or drive for long hours.
History
![]()
Humans have consumed caffeine since the Stone Age. Early peoples found that chewing the seeds, bark, or leaves of certain plants had the effects of easing fatigue, stimulating awareness, and elevating one's mood. Only much later was it found that the effect of caffeine was increased by steeping such plants in hot water. Many cultures have legends that attribute the discovery of such plants to people living many thousands of years ago.
According to one popular Chinese legend, the Emperor of China Shennong, reputed to have reigned in about 3000 BC, accidentally discovered that when some leaves fell into boiling water, a fragrant and restorative drink resulted. Shennong is also mentioned in Lu Yu's Cha Jing , a famous early work on the subject of tea. The history of coffee has been recorded as far back as the ninth century. During that time, coffee beans were available only in their native habitat, Ethiopia. A popular legend traces its discovery to a goatherder named Kaldi, who apparently observed goats that became elated and sleepless at night after grazing on coffee shrubs and, upon trying the berries that the goats had been eating, experienced the same vitality. The earliest literary mention of coffee may be a reference to Bunchum in the works of the 9th century Persian physician al-Razi. In 1587, Malaye Jaziri compiled a work tracing the history and legal controversies of coffee, entitled "Undat al safwa fi hill al-qahwa". In this work, Jaziri recorded that one Sheikh, Jamal-al-Din al-Dhabhani, mufti of Aden, was the first to adopt the use of coffee in 1454, and that in the 15th century the Sufis of Yemen routinely used coffee to stay awake during prayers.
Towards the close of the 16th century, the use of coffee was recorded by a European resident in Egypt, and about this time it came into general use in the Near East. The appreciation of coffee as a beverage in Europe, where it was first known as "Arabian wine," dates from the 17th century. A legend states that after the Ottoman Turks retreated from the walls of Vienna after losing a battle for the city, many sacks of coffee beans were found among their baggage. Europeans didn't know what to do with all the coffee beans, being unfamiliar with them. So Franz George Kolschitzky,
Dehydration
... of Chronic Dehydration by Albert Grazia, M.S., N.D. " Parsley a diuretic" Food Reference Website: Herbal Essentials ... herbal tea instead. ...
Herbal Diuretic - Water Pill Information : Vitabase
Vitabase Herbal Diuretic is a natural herbal formulation that supports the ... works in a gentle manner, so as to not cause dehydration ... Gourmet Tea; Heart Health; Joint & Bone Health ...
Diuretic Herbs
For making tea using herbal diuretic, add a teaspoon of dried herb to a cup of boiling water. ... can give rise to problems or symptoms, like, reduction in blood volume, dehydration ...
Herbal Diuretic
Gourmet Tea; Heart Health; Herbs; Joint and Bones; Men Health ... helps remove excess water from the body, Vitabase Herbal Diuretic ... This formula works gently and will not cause dehydration.
Anise Herb - Anise Tea - Herbal Recipes & Remedies for 100's of Herbs
Herbal Tea bags are a quick way to get the ... of Anise could have excessive diuretic effects and therefore should not be used in high dosages to avoid possible dehydration.
How to Use Cat's Claw as a Diuretic | eHow.com
Diuretics can cause dehydration. Make sure you discuss ... Take cat's claw in tincture or herbal form if you want to use it as a diuretic. Using cat's claw extract as a tea will only ...
Tea and Hydration
Tea and Hydration This article was given to us by the <> Tea ... Undiagnosed Diabetes Mellitus - Prolonged use of diuretic drugs - Physical activity Severe dehydration is associated ...
Herbal Diuretics: Safe, Natural Alternatives to the Water Pill ...
To make an herbal diuretic tea, combine one teaspoon of the dried herb of choice with one cup ... Over-using or abusing herbal diuretics can lead to dehydration or a reduction in blood ...
Herbal Tea Bags ...Remedies From Penn Herb Company, Ltd. 1-800-523 ...
Enjoyed after meals, Mentha-Mint Slim Tea, serves as a diuretic that helps to increase liver and ... Honey Lemon Ultra Slim herbal tea offers a rich, satisfying taste in hot or ice tea
Herbal Diuretic - Weight Loss
Herbal Diuretic : An herbal formula that helps remove excess water ... This formula works gently and will not cause dehydration. ... Hydroxycut Green Tea: 1 Bottle $14.95 $11.95: Temporarily ...