Monday, May 30, 2011


Coffee is a brewed drink prepared from roasted seeds, called coffee beans, of the coffee plant. Coffee beans are found in coffee cherries, which grow on trees in over 70 countries, cultivated primarily in Latin America, Southeast Asia, and Africa. 'Green Unroasted' coffee is one of the most traded agricultural commodities in the world. Coffee can have a stimulating effect on humans due to its caffeine content. It is one of the most-consumed beverages in the world.
Coffee has played a crucial role in many societies. The energizing effect of the coffee bean plant is thought to have been discovered in the northeast region of Ethiopia, and the cultivation of coffee first expanded in the Arab world. The earliest credible evidence of coffee drinking appears in the middle of the 15th century, in the Sufi monasteries of Yemen in southern Arabia. From the Muslim world, coffee spread to Italy, then to the rest of Europe, to Indonesia, and to the Americas. In East Africa and Yemen, it was used in religious ceremonies. As a result, the Ethiopian Church banned its secular consumption, a ban in effect until the reign of Emperor Menelik II of Ethiopia. It was banned in Ottoman Turkey during the 17th century for political reasons, and was associated with rebellious political activities in Europe.
Coffee berries, which contain the coffee seed, or "bean", are produced by several species of small evergreen bush of the genus Coffea. The two most commonly grown are the highly regarded Coffea arabica, and the 'robusta' form of the hardier Coffea canephora. The latter is resistant to the devastating coffee leaf rust (Hemileia vastatrix). Once ripe, coffee berries are picked, processed, and dried. The seeds are then roasted to varying degrees, depending on the desired flavor. They are then ground and brewed to create coffee. Coffee can be prepared and presented in a variety of ways.
An important export commodity, coffee was the top agricultural export for twelve countries in 2004, and it was the world's seventh-largest legal agricultural export by value in 2005. Some controversy is associated with coffee cultivation and its impact on the environment. Many studies have examined the relationship between coffee consumption and certain health conditions; whether the overall effects of coffee are ultimately positive or negative has been widely disputed. The method of brewing coffee has been found to be important to its health effects.
The first reference to "coffee" in the English language, in the form chaoua, dates to 1598. In English and other European languages, coffee derives from the Ottoman Turkish kahve, via the Italian caffè. The Turkish word in turn was borrowed from the Arabic qahwah. Arab lexicographers maintain that qahwah originally referred to a type of wine, and gave its etymology, in turn, to the verb qahiya, signifying "to have no appetite", since this beverage was thought to dull one's hunger. Several alternative etymologies exist that hold that the Arab form may disguise a loanword from an Ethiopian or African source, suggesting Kaffa, the highland in southwestern Ethiopia as one, since the plant is indigenous to that area. However, the term used in that region for the berry and plant is bunn, the native name in Shoa being būn.
Several species of shrub of the genus Coffea produce the berries from which coffee is extracted. The two main species commercially cultivated are Coffea canephora (predominantly a form known as 'robusta') and C. arabica. C. arabica, the original and most highly regarded species, is native to the southwestern highlands of Ethiopia and the Boma Plateau in southeastern Sudan and possibly Mount Marsabit in northern Kenya. C. canephora is native to western and central subsaharan Africa, from Guinea to the Uganda and southern Sudan. Less popular species are C. liberica, excelsa, stenophylla, mauritiana, and racemosa.
All coffee plants are classified in the large family Rubiaceae. They are evergreen shrubs or small trees that may grow 5 m (15 ft) tall when unpruned. The leaves are dark green and glossy, usually 10–15 cm (4–6 in) long and 6 cm (2.4 in) wide. The flowers are axillary, and clusters of fragrant white flowers bloom simultaneously and are followed by oval berries of about 1.5 cm (0.6 in). Green when immature, they ripen to yellow, then crimson, before turning black on drying. Each berry usually contains two seeds, but 5–10% of the berries have only one; these are called peaberries. Berries ripen in seven to nine months.
Coffea arabica is predominantly self-pollinating, and as a result the seedlings are generally uniform and vary little from their parents. In contrast, Coffea canephora, C. excelsa, and C. liberica are self-incompatible and require outcrossing. This means that useful forms and hybrids must be propagated vegetatively. Cuttings, grafting, and budding are the usual methods of vegetative propagation. On the other hand, there is great scope for experimentation in search of potential new strains.
In 2009 Brazil was the world leader in production of green coffee, followed by Vietnam, Indonesia and Colombia. Arabica coffee beans are cultivated in Latin America, eastern Africa, Arabia, or Asia. Robusta coffee beans are grown in western and central Africa, throughout Southeast Asia, and to some extent in Brazil.
Beans from different countries or regions can usually be distinguished by differences in flavor, aroma, body, and acidity. These taste characteristics are dependent not only on the coffee's growing region, but also on genetic subspecies (varietals) and processing. Varietals are generally known by the region in which they are grown, such as Colombian, Java and Kona.
Coffee Processing
Coffee berries and their seeds undergo several processes before they become the familiar roasted coffee. Berries have been traditionally selectively picked by hand; a labor intensive method, it involves the selection of only the berries at the peak of ripeness. More commonly, crops are strip picked, where all berries are harvested simultaneously regardless of ripeness by person or machine. After picking, green coffee is processed by one of two methods—the dry process method, simpler and less labor intensive as the berries can be strip picked, and the wet process method, which incorporates fermentation into the process and yields a mild coffee.
Then they are sorted by ripeness and color and the flesh of the berry is removed, usually by machine, and the seeds—usually called beans—are fermented to remove the slimy layer of mucilage still present on the bean. When the fermentation is finished, the beans are washed with large quantities of fresh water to remove the fermentation residue, which generates massive amounts of coffee wastewater. Finally, the seeds are dried. The best (but least used) method of drying coffee is using drying tables. In this method, the pulped and fermented coffee is spread thinly on raised beds, which allows the air to pass on all sides of the coffee, and then the coffee is mixed by hand. In this method the drying that takes place is more uniform, and fermentation is less likely. Most African coffee is dried in this manner and certain coffee farms around the world are starting to use this traditional method. Next, the coffee is sorted, and labeled as green coffee. Another way to let the coffee beans dry is to let them sit on a concrete patio and rake over them in the sunlight. Some companies use cylinders to pump in heated air to dry the coffee beans, though this is generally in places where the humidity is very high.
The Roasting Process
The next step in the process is the roasting of the green coffee. Coffee is usually sold in a roasted state, and with rare exceptions all coffee is roasted before it is consumed. It can be sold roasted by the supplier, or it can be home roasted. The roasting process influences the taste of the beverage by changing the coffee bean both physically and chemically. The bean decreases in weight as moisture is lost and increases in volume, causing it to become less dense. The density of the bean also influences the strength of the coffee and requirements for packaging.
The actual roasting begins when the temperature inside the bean reaches approximately 200 °C (392 °F), though different varieties of beans differ in moisture and density and therefore roast at different rates. During roasting, caramelization occurs as intense heat breaks down starches in the bean, changing them to simple sugars that begin to brown, changing the color of the bean. Sucrose is rapidly lost during the roasting process and may disappear entirely in darker roasts. During roasting, aromatic oils and acids weaken, changing the flavor; at 205 °C (401 °F), other oils start to develop. One of these oils is caffeol, created at about 200 °C (392 °F), which is largely responsible for coffee's aroma and flavor.
Grading the Roasted beans
Depending on the color of the roasted beans as perceived by the human eye, they will be labeled as light, medium light, medium, medium dark, dark, or very dark. A more accurate method of discerning the degree of roast involves measuring the reflected light from roasted beans illuminated with a light source in the near infrared spectrum. This elaborate light meter uses a process known as spectroscopy to return a number that consistently indicates the roasted coffee's relative degree of roast or flavor development.
Roast characteristics
Darker roasts are generally bolder because they have less fiber content and a more sugary flavor. Lighter roasts have a more complex and therefore perceived stronger flavor from aromatic oils and acids otherwise destroyed by longer roasting times. A small amount of chaff is produced during roasting from the skin left on the bean after processing. Chaff is usually removed from the beans by air movement, though a small amount is added to dark roast coffees to soak up oils on the beans.
Decaffeination may also be part of the processing that coffee seeds undergo. Seeds are decaffeinated when they are still green. Many methods can remove caffeine from coffee, but all involve either soaking the green beans in hot water (often called the "Swiss water" process) or steaming them, then using a solvent to dissolve caffeine-containing oils. Decaffeination is often done by processing companies, and the extracted caffeine is usually sold to the pharmaceutical industry.
Coffee beans must be ground and brewed to create a beverage. Almost all methods of preparing coffee require the beans to be ground and mixed with hot water for long enough to extract the flavor, but without boiling for more than an instant; boiling develops an unpleasant "cooked" flavor caused by over extraction from the beans that draws out unnecessary bitter compounds. Finally, the spent grounds are removed from the liquid, and the liquid is consumed. There are many variations in the fineness of grind, the ways in which the water extracts the flavor, additional flavorings (sugar, milk, spices), and the removal of the spent grounds. The ideal holding temperature is 79 to 85 °C (174 to 185 °F) and the ideal serving temperature is 68 to 79 °C (154 to 174 °F).
Coffee may be brewed by several methods: boiled, steeped, or pressured
The espresso method forces hot pressurized and vaporized water through ground coffee. As a result of brewing under high pressure (ideally between 9–10 atm), the espresso beverage is more concentrated (as much as 10 to 15 times the quantity of coffee to water as gravity-brewing methods can produce) and has a more complex physical and chemical constitution. A well-prepared espresso has a reddish-brown foam called crema that floats on the surface. Other pressurized water methods include the moka pot and vacuum coffee maker.
Coffee may also be brewed in cold water, resulting in a brew lower in acidity than most hot-brewing methods produce, by steeping the coarsely ground beans in cold water for several hours, then filtering them.
Once brewed, coffee may be presented in a variety of ways. Drip-brewed, percolated, or French-pressed/cafetière coffee may be served with a dairy product such as milk or cream, or dairy substitute (colloquially known as white coffee), or not (black coffee). It may be sweetened with sugar or artificial sweetener. When served cold, it is called iced coffee.
Espresso-based coffee has a wide variety of possible presentations. In its most basic form, espresso is served alone as a shot or with hot water added, known as Caffè Americano. Reversely, long black is made by pouring espresso in water, which retains the crema compared to Caffè Americano. Milk is added in various forms to espresso: steamed milk makes a caffè latte, equal parts steamed milk and milk froth make a cappuccino, and a dollop of hot foamed milk on top creates a caffè macchiato. The use of steamed milk to form patterns such as hearts or maple leaves is referred to as latte art.
A number of products are sold for the convenience of consumers who do not want to prepare their own coffee.
Instant coffee is dried into soluble powder or freeze-dried into granules that can be quickly dissolved in hot water. Originally invented in 1907, it rapidly gained in popularity in many countries in the post-war period, with Nescafé the most popular product. Many consumers determined that the convenience in preparing a cup of instant coffee more than made up for a perceived inferior taste. Paralleling (and complementing) the rapid rise of instant coffee was the coffee vending machine, invented in 1947 and multiplying rapidly through the 1950s.
Canned coffee has been popular in Asian countries for many years, particularly in China, Japan, and South Korea. Vending machines typically sell varieties of flavored canned coffee, much like brewed or percolated coffee, available both hot and cold. Japanese convenience stores and groceries also have a wide availability of bottled coffee drinks, which are typically lightly sweetened and pre-blended with milk. Bottled coffee drinks are also consumed in the United States. Liquid coffee concentrates are sometimes used in large institutional situations where coffee needs to be produced for thousands of people at the same time. It is described as having a flavor about as good as low-grade robusta coffee, and costs about 10¢ a cup to produce. The machines used can process up to 500 cups an hour, or 1,000 if the water is preheated.
Coffee can also be incorporated with alcohol in beverages—it is combined with whiskey in Irish coffee, and forms the base of alcoholic coffee liqueurs such as Kahlúa, and Tia Maria.


Coffee Beverages

An Affogato (Italian for "drowned") is a coffee-based beverage or dessert. "Affogato style", which refers to the act of topping a drink or dessert with espresso, may also incorporate caramel sauce or chocolate sauce.
Caffè Americano or simply Americano (the name is also spelled with varying capitalization and use of diacritics: e.g. Café Americano, Cafe Americano, etc.) is a style of coffee prepared by adding hot water to espresso, giving a similar strength to but different flavor from regular drip coffee. The strength of an Americano varies with the number of shots of espresso added.
  • Long black
  • Lungo
  • Red eye
A Café au lait is a French coffee drink. In Europe, "café au lait" stems from the same continental tradition as "caffè Latte" in Italy, "café con leche" in Spain, "kawa biała" ("white coffee") in Poland, "Milchkaffee" in Germany, "Grosser Brauner" in Austria, "koffie verkeerd" in Netherlands, and "café com leite" in Portugal, simply "coffee with milk". In northern Europe, café au lait is the name most often used in coffee shops. It is a coffee beverage consisting strong or bold coffee (sometimes espresso) mixed with scalded milk in approximately a 1:1 ratio.
Café Bombón was made popular in Valencia, Spain, and spread gradually to the rest of the country. It might have been re-created and modified to suit European tastebuds as in many parts of Asia such as Malaysia, Thailand and Singapore the same recipe for coffee which is called "Kopi Susu Panas" (Malaysia) or "Kafe Ron" (Thailand) has already been around for decades and is very popular in "mamak" stalls and "kopitiams" in Malaysia. A café bombón, however uses espresso served with sweetened condensed milk in a 1:1 ratio whereas the Asian version uses ground coffee and sweetened condensed milk at the same ratio. For café bombón, the condensed milk is added to the espresso. For visual effect, a glass is used, and the condensed milk is added slowly to sink underneath the coffee and create two separate bands of contrasting colour – though these layers are customarily stirred together before consumption. Some establishments merely serve an espresso with a sachet of condensed milk for patrons to make themselves.
Caffè latte: The Italian name for a café au lait.
A Café mélange is a black coffee mixed (French "mélange") or covered with whipped cream, popular in Austria, Switzerland and the Netherlands.
A Coffee milk is a drink similar to chocolate milk; however, instead of chocolate syrup, coffee syrup is used. It is the official state drink of Rhode Island in the United States.
A Café mocha is a variant of a caffè latte. Like a latte, it is typically one third espresso and two thirds steamed milk, but a portion of chocolate is added, typically in the form of a chocolate syrup, although other vending systems use instant chocolate powder. Mochas can contain dark or milk chocolate.
The term Moccaccino is used in some regions of Europe and the Middle East to describe Café Latte with cocoa or chocolate. In the U.S. it usually refers to a cappuccino made with chocolate.
Cà phê sa đá or cafe sua da is a unique Vietnamese coffee recipe. Literally, ca phe sua da means "iced milk coffee". Ca phe sua da can be made simply by mixing black coffee with about a quarter to a half as much sweetened condensed milk and then pouring it over ice. A substitute made by many Vietnamese immigrants in the Southern U.S., particularly in Louisiana is a dark French roast, often with chicory; otherwise an imported Vietnamese-grown and roasted coffee is used when it is available. The coffee is traditionally brewed with a small metal Vietnamese drip filter into a cup containing the condensed milk. The condensed milk and coffee are stirred together and then poured over the ice. Ca phe sua nong (Vietnamese: 'cà phê sa nóng') — literally, "hot milk coffee" — is made by excluding the ice.
In Spain, there is a similar beverage called Café del Tiempo ([Summer] Weather Coffee) or Café con Hielo (Coffee with Ice). Similarly, Café Bombón can be served with ice. The coffee is served in a small cup and an empty small glass with ices cubes. Sugar or condensed milk is added in the small cup while the coffee is still hot, and then the coffee is poured in the small glass with ices. When the coffee is cooled, the remaining ice is removed with the help of a spoon.
It is a coffee-based drink prepared with espresso, hot milk, and steamed milk foam. A cappuccino differs from a caffè latte in that it is prepared with much less steamed or textured milk than the caffè latte with the total of espresso and milk/foam making up between approximately 150 ml and 180 ml (5 and 6 fluid ounces). A cappuccino is traditionally served in a porcelain cup, which has far better heat retention characteristics than glass or paper. The foam on top of the cappuccino acts as an insulator and helps retain the heat of the liquid, allowing it to stay hotter longer.
A Cortado is an espresso (also known as "Pingo" or "Garoto") "cut" (from the Spanish and Portuguese cortar) with a small amount of warm milk to reduce the acidity. The ratio of milk to coffee is between 1:1 – 1:2, and the milk is added after the espresso. The steamed milk hasn't much foam, but many baristas make some micro foam to make latte art. It is popular in Spain and Portugal, as well as throughout Latin America, where it is drunk in the afternoon. In Cuba, it is known as a cortadito, and in Catalan it's called a tallat or trencat. It's usually served in a special glass, often with a metal ring base and a metal wire handle. There are several variations, including cortado condensada (espresso with condensed milk) and leche y leche (with condensed milk and cream on top).
Eiskaffee, literally "ice cream coffee", is a popular German drink consisting of chilled coffee, milk, sweetener, vanilla ice cream, and sometimes whipped cream.
An Espresso Romano is a shot of espresso with a small rind of lemon and sugar added to it.
A Flat White is prepared by pouring the creamy steamed milk from the bottom of the jug over a single shot (30ml) of espresso.
The drink is a coffee style originating from New Zealand and Australia and is sometimes served in a small 150-160ml ceramic cup. The stretched and texturised milk is prepared by entraining air into the milk and folding the top layer into the lower layers. To achieve the "flat", non-frothy texture the steamed milk is poured from the bottom of the jug, holding back the lighter froth on the top in order to access milk with smaller bubbles, making the drink smooth and velvety in texture. This leads to a white coffee with the cream on top still intact.
Frappuccino is the name and registered trademark of a Starbucks blended ice beverage and a bottled coffee beverage.
Galão is a hot drink from Portugal made of espresso and foamed milk. In all similar to caffè latte or café au lait, it comes in a tall glass with about one quarter coffee, 3 quarters foamed milk. When the proportion is 1:1 it is called "meia de leite" and it comes in a cup.
Greek frappé coffee (Café frappé) is a foam-covered iced coffee drink made from spray-dried instant coffee. It is very popular in Greece especially during summer, but has now spread on to other countries. In French, when describing a drink, the word frappé means shaken and/or chilled; however, in popular Greek culture, the word frappé is predominantly taken to refer to the shaking associated with the preparation of a café frappé.
Iced coffee is a cold variant of the normally hot beverage coffee.
Indian filter coffee or South Indian Coffee, also known as Madras Filter Coffee or Kaapi (Tamil phonetic rendering of "coffee') is a sweet milky coffee made from dark roasted coffee beans (70%–80%) and chicory (20%–30%), especially popular in the southern states of Andhra Pradesh, Karnataka, Kerala and Tamil Nadu. The most commonly used coffee beans are Peaberry (preferred), Arabica, Malabar and Robusta grown in the hills of Kerala (Malabar region), Karnataka (Kodagu, Chikkamagaluru) and Tamil Nadu (Nilgiris District,Yercaud and Kodaikanal).
Instant coffee is a beverage derived from brewed coffee beans. Through various manufacturing processes the coffee is dehydrated into the form of powder or granules. These can be rehydrated with hot water to provide a drink similar (though not identical) to conventional coffee. At least one brand of instant coffee is also available in concentrated liquid form.
Irish Coffee is coffee combined with whiskey and cream, often further sweetened with sugar. Also available as a flavor of ice cream.
Kopi susu is found in (at least) Malaysian Borneo and Indonesia and very similar to the preceding entry for Ca phe sua nong. Literally, kopi susu means "coffee milk". Served in a glass kopi susu can be made simply by mixing black coffee (arabica) with about a quarter to a half a glass of sweetened condensed milk then let stand to cool and allow the grounds to sink on the bottom. You should not drink this to the end unless you want to "eat" the ground coffee. Kopi Turbruk is as above but uses sugar instead of sweetened condensed milk.
A Liqueur coffee, as its name suggests, is a coffee brew with a 25ml shot of liqueur. This brew is usually served in a clear, clean, pre-heated, liqueur coffee glass with the coffee and cream separated for good visual and taste effect. The liqueur of choice is added first with a teaspoon of raw cane sugar mixed in. The glass in then filled to within an inch of the top with good, strong, fresh filter coffee. Fresh, chilled, additive free, slightly whipped cream is then poured carefully over the back of a cold teaspoon, so that it floats on top of the coffee and liqueur mixture. The sugar is required in the coffee mixture to help the cream float.
Macchiato, means 'stained', is an Espresso with a dash of foamed milk. At first sight it resembles a small Cappuccino but even if the ingredients are the same as those used for Cappuccino a Macchiato has a much stronger and aromatic taste. The milk is foamed directly into the espresso cup, which is then put under the coffee outlet. The espresso is then drawn into the cup. Cocoa is then sprinkled over the drink.
Mochasippi is a drink prepared by baristas in Community Coffee houses located in the Southern United States, commonly known as CC's. It is similar to the Mocha Frappuccino of Starbucks coffee houses. Unlike a Frappuccino, a Mochasippi contains actual shots of espresso rather than a powdered instant coffee.
Naked Coffee is the name given to an espresso coffee drink extracted using a special porta-filter which makes a rich creamy double shot of espresso coffee. Once extracted this liquid can be used to make any coffee drink. An example is the Naked Latte or Naked Lady or Naked Mocha, Naked Cappuccino etc. made by Blvd Coffee, Los Gatos, CA.
Turkish coffee: Beans for Turkish coffee are ground or pounded to the finest possible powder, finer than for any other way of preparation. Preparation of Turkish coffee consists of immersing the coffee grounds in water which is most of the time hot but not boiling for long enough to dissolve the flavor some compounds. While prolonged boiling of coffee gives it an unpleasant "cooked" or "burnt" taste, very brief boiling does not, and bringing it to the boil shows without guesswork that it has reached the appropriate temperature.
In Turkey, four degrees of sweetness are used. The Turkish terms and approximate amounts are as follows: sade (plain; no sugar), az şekerli (little sugar; half a level teaspoon of sugar), orta şekerli (medium sugar; one level teaspoon), and çok şekerli (a lot of sugar; one and a half or two level teaspoons). The coffee and the desired amount of sugar are stirred until all coffee sinks and the sugar is dissolved. Following this, the spoon is removed and the pot is put on moderate heat; if too high, the coffee comes to the boil too quickly, without time to extract the flavor. No stirring is done beyond this point, as it would dissolve the foam. Just as the coffee comes to the boil the pot is removed from the heat. It is usually kept off the heat for a short time, then brought to the boil a second and a third time, then the coffee is poured into the cups. Getting the thickest possible layer of foam is considered the peak of the coffee maker's art. One way to maximize this is to pour slowly and try to lift the pot higher and higher as the pouring continues. Regardless of these techniques, getting the same amount of foam into all cups is hard to achieve, and the cup with the most foam is considered the best of the lot.
A "Vienna coffee" is the name of a popular traditional cream based coffee beverage. It is made by preparing two shots of strong black espresso in a standard sized coffee cup and infusing the coffee with whipped cream (as a replacement for milk and sugar) until the cup is full. Then the cream is twirled and optionally topped off with chocolate sprinklings. The coffee is drunk through the cream top.
Yuanyang, sometimes also called Ying Yong, is a popular beverage in Hong Kong, made of a mixture of coffee and Hong Kong-style milk tea. It was originally served at dai pai dongs (open air food vendors) and cha chaan tengs (cafe), but is now available in various types of restaurants. It can be served hot or cold. The name yuanyang, which refers to mandarin ducks, is a symbol of conjugal love in Chinese culture, as the birds usually appear in pairs and the male and female look very different. This same connotation of "pair" of two unlike items is used to name this drink.


Friday, May 27, 2011

Health Benefits of Coffee

The health effects of coffee have been studied to determine how coffee drinking affects humans. Coffee contains several compounds which are known to affect human body chemistry. The coffee bean itself contains chemicals which are mild psychotropics for humans as a defense mechanism of the Coffee plant. These chemicals are toxic in large doses, or even in their normal amount when consumed by many creatures which may otherwise have threatened the beans in the wild. Coffee contains caffeine, which acts as a stimulant.
Recent research has uncovered additional stimulating effects of coffee which are not related to its caffeine content. Coffee contains an as yet unknown chemical agent which stimulates the production of cortisone and adrenaline, two stimulating hormones.
For occasions when one wants to enjoy the flavour of coffee with almost no stimulation, decaffeinated coffee (also called decaf) is available. This is coffee from which most of the caffeine has been removed, by the Swiss water process (which involves the soaking of raw beans to remove the caffeine) or the use of a chemical solvent such as trichloroethylene ("tri"), or the more popular methylene chloride, in a similar process. Another solvent used is ethyl acetate; the resultant decaffeinated coffee is marketed as "natural decaf" because ethyl acetate is naturally present in fruit. Extraction with supercritical carbon dioxide has also been employed.
Decaffeinated coffee usually loses some flavour compared to normal coffee. There are also coffee alternatives that resemble coffee in taste but contain no caffeine. These are available both in ground form for brewing and in instant form.
Caffeine dependency and withdrawal symptoms are well-documented.
Reduced risk of Alzheimer's disease and Dementia
Several studies comparing moderate coffee drinkers (defined as 3–5 cups per day) with light coffee drinkers (defined as 0–2 cups per day) found that those who drank more coffee were significantly less likely to develop Alzheimer's disease later in life. A longitudinal study in 2009 found that moderate coffee drinkers had reduced risk of developing dementia in addition to Alzheimer's disease.
Reduced risk of gallstone disease
Drinking caffeinated coffee has been correlated with a lower incidence of gallstones and gallbladder disease in both men and women in two studies performed by the Harvard School of Public Health. A lessened risk was not seen in those who drank decaffeinated coffee. A recent study showed that roast coffee protected primary neuronal cells against hydrogen peroxide-induced cell death.
Reduced risk of Parkinson's disease
A study comparing heavy coffee drinkers (3.5 cups a day) with non-drinkers found that the coffee drinkers were significantly less likely to contract Parkinson's disease later in life. Likewise, a second study found an inverse relationship between the amount of coffee regularly drunk and the likelihood of developing Parkinson's disease.
Cognitive performance
Many people drink coffee for its ability to increase short term recall.
Likewise, in tests of simple reaction time, choice reaction time, incidental verbal memory, and visuospatial reasoning, participants who regularly drank coffee were found to perform better on all tests, with a positive relationship between test scores and the amount of coffee regularly drunk. Elderly participants were found to have the largest effect associated with regular coffee drinking. Another study found that women over the age of 80 performed significantly better on cognitive tests if they had regularly drunk coffee over their lifetimes.
Analgesic enhancement
Coffee contains caffeine, which increases the effectiveness of pain killers, especially migraine and headache medications. For this reason, many over-the-counter headache drugs include caffeine in their formula.
Coffee intake may reduce one's risk of diabetes mellitus type 2 by up to half. While this was originally noticed in patients who consumed high amounts (7 cups a day), the relationship was later shown to be linear.
Liver protection
Coffee can also reduce the incidence of cirrhosis of the liver and has been linked to a reduced risk of hepatocellular carcinoma, a primary liver cancer that usually arises in patients with preexisting cirrhosis. The exact mechanism and the amount of coffee needed to achieve a beneficial effect have long been unclear. The cytokine transforming growth factor (TGF) beta has long been recognized for promoting fibrosis ability acting through the Smad family of transcription factors. In an interesting report recently published in the Journal of Hepatology, Gressner and colleagues provide the first mechanistic context for the epidemiological studies on coffee drinkers by showing that caffeine may have potent anti-fibrotic capabilities through its ability to antagonize the Smad pathway.
Coffee consumption is also correlated to a reduced risk of oral, esophageal, and pharyngeal cancer. In ovarian cancer, no benefit was found. In the Nurses' Health Study, a modest reduction in breast cancer was observed in postmenopausal women only, which was not confirmed in decaffeinated coffee. According to one study, coffee protects the liver from cancer. Another preliminary study found a correlation between coffee consumption and a lower risk of aggressive prostate cancer.
Coffee moderately reduces the incidence of dying from cardiovascular disease, according to a large prospective cohort study published in 2008. A 2009 prospective study in Japan following nearly 77,000 individuals aged 40 to 79 found that coffee consumption, along with caffeine intake, was associated with a reduced risk of dying from cardiovascular disease.
Coffee is also a powerful stimulant for peristalsis and is sometimes considered to prevent constipation. However, coffee can also cause excessively loose bowel movements. The stimulative effect of coffee consumption on the colon is found in both caffeinated and decaffeinated coffee.
Practitioners in alternative medicine often recommend coffee enemas for "cleansing of the colon" due to its stimulus of peristalsis, although medicine has not proven any benefits of the practice.
Contrary to popular belief, caffeine does not act as a diuretic when consumed in moderation, and does not lead to dehydration or to a water-electrolyte imbalance; current evidence suggests that caffeinated beverages contribute to the body's daily fluid requirements no differently from pure water.
Coffee contains the anticancer compound methylpyridinium. This compound is not present in significant amounts in other food materials. Methylpyridinium is not present in raw coffee beans but is formed during the roasting process from trigonelline, which is common in raw coffee beans. It is present in both caffeinated and decaffeinated coffee, and even in instant coffee. A recent study shows that roast coffee contains more lipophilic antioxidants and chlorogenic acid lactones and are more protective against hydrogen peroxide-induced cell death in primary neuronal cells than green coffee.
Prevention of dental caries
The tannins in coffee may reduce the cariogenic potential of foods. In vitro experiments have shown that these polyphenolic compounds may interfere with glucosyltransferase activity of mutans streptococci, which may reduce plaque formation.
Coffee consumption decreased risk of gout in men over age 40. In a large study of over 45,000 men over a 12-year period, the risk for developing gout in men over 40 was inversely proportional with the amount of coffee consumed.