Guarana (pronounced /ˌɡwɑrəˈnɑː/, from the Portuguese guaraná, Paullinia cupana (syn. P. crysan, P. sorbilis) is a climbing plant in the maple family, Sapindaceae, native to the Amazon basin and especially common in Brazil.
Guarana features large leaves and clusters of flowers, and is best known for its fruit, which is about the size of a coffee bean. As a dietary supplement, guarana is an effective energy booster: it contains about twice the caffeine found in coffee beans (about 2–4.5% caffeine in guarana seeds compared to 1–2% for coffee beans).

As with other plants producing caffeine, the high concentration of caffeine is a defensive toxin that repels pathogens from the berry and its seeds.

The guarana fruit's color ranges from brown to red and contains black seeds which are partly covered by white arils. The color contrast when the fruit has been split open has been likened to eyeballs; this has formed the basis of a myth.

History and culture
The word guarana comes from the Portuguese guaraná, which has its origins in the Sateré-Maué word for the plant, warana.

Guarana plays an important role in Tupi and Guaraní Brazilian culture. According to a myth attributed to the Sateré-Maué tribe, guarana's domestication originated with a deity killing a beloved village child.
In order to console the villagers, a more benevolent god plucked the left eye from the child and planted it in the forest, resulting in the wild variety of guarana. The god then plucked the right eye from the child and planted it in the village, giving rise to domesticated guarana.

The Guaranís would make a tea by shelling and washing the seeds, followed by pounding them into a fine powder. The powder is kneaded into a dough and then shaped into cylinders. This product is known as guarana bread or Brazilia coke, which would be grated and then immersed into hot water along with sugar.

This plant was introduced to European Colonizers and Europe in the 17th century by Father Felip Betendorf. By 1958, guarana was commercialized.

Composition
Below are some of the chemicals found in guarana; all of them are found in the seeds, although other parts of the plant may contain them as well.

According to the Biological Magnetic Resonance Data Bank, guaranine is defined as only the caffeine chemical in guarana, it is identical to the caffeine chemical derived from other sources, for example coffee, tea, and maté.
Guaranine, theine, and mateine are all synonyms for caffeine when the definitions of those words include none of the properties and chemicals of their host plants except the chemical caffeine. Natural sources of caffeine contain widely varying mixtures of xanthine alkaloids other than caffeine, including the cardiac stimulants theophylline and theobromine and other substances such as polyphenols which can form insoluble complexes with caffeine.

Uses

Guarana soft drinks, such as Guaraná Antarctica, are very popular in Brazil.Guarana is used in sweetened or carbonated soft drinks and energy shots, an ingredient of herbal tea or contained in capsules. Generally, South America obtains most of its caffeine from guarana.

Beverages
Brazil, which is the third-largest consumer of soft drinks in the world, produces several soft drink brands from guarana extract. Exceeding Brazilian sales of cola drinks, guarana-containing beverages may cause jitters associated with drinking coffee.

Cognitive effects
As guarana is rich in caffeine, it is of interest for its potential effects on cognition. In rats, guarana increased memory retention and physical endurance when compared with a placebo.

A 2007 human pilot study assessed acute behavioral effects to four doses (37.5 mg, 75 mg, 150 mg and 300 mg) of guarana extract. Memory, alertness and mood were increased by the two lower doses, confirming previous results of cognitive improvement following 75 mg guarana.

Other uses and side-effects
Guarana seed powderIn the United States, guarana has the status of being generally recognized as safe (GRAS).

Preliminary research has shown guarana may affect how quickly the body perceives itself to be full. One study showed an average 11.2 pound (5.1 kilogram) weight loss in a group taking a mixture of yerba mate, guarana, and damiana, compared to an average one pound loss in a placebo group after 45 days.
Although inconclusive about specific effects due only to guarana, this study differs from another showing no effect on body weight of a formula containing guarana.

Guarana extract reduced aggregation of rabbit platelets by up to 37 percent below control values and decreased platelet thromboxane formation from arachidonic acid by 78 percent below control values.
It is not known if such platelet action has any effect on the risk of heart attack or ischemic stroke.

Other laboratory studies showed antioxidant and antibacterial effects, and also fat cell reduction in mice (when combined with conjugated linoleic acid) from chronic intake of guarana.

From anecdotal evidence of excessive consumption of energy drinks, guarana may contribute (alone or in combination with caffeine and taurine) to onset of seizures in some people.

Growing habitats
Noni FlowerNoni grows in shady forests as well as on open rocky or sandy shores. It reaches maturity in about 18 months and then yields between 4–8 kilograms (8.8–18 lb) of fruit every month throughout the year.
It is tolerant of saline soils, drought conditions, and secondary soils. It is therefore found in a wide variety of habitats: volcanic terrains, lava-strewn coasts, and clearings or limestone outcrops. It can grow up to 9 metres (30 ft) tall, and has large, simple, dark green, shiny and deeply veined leaves.
The plant flowers and fruits all year round and produces a small white flower. The fruit is a multiple fruit that has a pungent odor when ripening, and is hence also known as cheese fruit or even vomit fruit. It is oval and reaches 4–7 centimetres (1.6–2.8 in) in size.
At first green, the fruit turns yellow then almost white as it ripens. It contains many seeds.
It is sometimes called starvation fruit.
Despite its strong smell and bitter taste, the fruit is nevertheless eaten as a famine food and, in some Pacific islands, even a staple food, either raw or cooked. Southeast Asians and Australian Aborigines consume the fruit raw with salt or cook it with curry. The seeds are edible when roasted.
The noni is especially attractive to weaver ants, which make nests out of the leaves of the tree. These ants protect the plant from some plant-parasitic insects. The smell of the fruit also attracts fruit bats, which aid in dispersing the seeds.
Nutrients
Noni fruit in HonoluluNoni fruit powder is high in carbohydrates and dietary fiber. According to the College of Tropical Agriculture and Human Resources at the University of Hawaii at Mānoa, a 100 g sample of the powder contains 71% carbohydrate and 36% fiber. The sample also contained 5.2% protein and 1.2% fat.
These macronutrients evidently reside in the fruit pulp, as noni juice has sparse amounts of macronutrients.
The main micronutrients of noni pulp powder include 9.8 mg of vitamin C per 1200 mg sample, as well as 0.048 mg niacin (vitamin B3), 0.02 mg iron and 32.0 mg potassium. Vitamin A, calcium and sodium are present in moderate amounts.
When noni juice alone is analyzed and compared to pulp powder, only vitamin C is retained at a high level, 33.6 mg per 100 g of juice.
Although the most significant nutrient feature of noni pulp powder or juice is its high vitamin C content, noni fruit juice provides only about half the vitamin C of a raw navel orange.
Sodium levels in noni juice (about 3% of DRI) are high compared to an orange.
Although the potassium content appears relatively high for noni, this total is only about 3% of the Recommended Dietary Allowance and so would not be considered excessive. Noni juice is otherwise similar in micronutrient content to a raw orange.
Noni fruit contains a number of phytochemicals, including lignans, oligo- and polysaccharides, flavonoids, iridoids, fatty acids, scopoletin, catechin, beta-sitosterol, damnacanthal, and alkaloids. Although these substances have been studied for bioactivity, current research does not conclude anything about their effects on human health.
These phytochemicals are not unique to noni, as they exist in various plants.
Possible medicinal properties
Noni has been evaluated unsuccessfully in preliminary clinical trials for possible use in treating cancer, although the US National Cancer Institute has undertaken further preliminary studies for potential preventive effects against breast cancer. Since 2007, there have been no other registered clinical trials on potential health benefits or anti-disease effects of noni which remains scientifically undefined for any effect on human health.
Traditional medicine
Applications in folk medicine such as those discussed below have not been verified by modern science or confirmed scientifically to enhance health or prevent disease.
In China, Samoa, Japan, and Tahiti, various parts of the tree (leaves, flowers, fruits, bark, roots) serve as tonics and to contain fever, to treat eye and skin problems, gum and throat problems as well as constipation, stomach pain, or respiratory difficulties. In Malaysia, heated noni leaves applied to the chest are believed to relieve coughs, nausea, or colic.
The noni fruit is taken, in Indochina especially, for asthma, lumbago, and dysentery. As for external uses, unripe fruits can be pounded, then mixed with salt and applied to cut or broken bones. In Hawaii, ripe fruits were once applied to draw out pus from an infected boil.
Although unsupported by science, the green fruit, leaves and the root/rhizome were traditionally used to treat menstrual cramps, bowel irregularities and urinary tract infections.
Consumer applications
The bark of the great morinda produces a brownish-purplish dye for batik making. In Hawaii, yellowish dye is extracted from its roots to dye cloth.
The fruit may be used as a shampoo in Malaysia, where it is said to be helpful against head lice. There have been recent applications for the use of noni seed oil which contains linoleic acid possibly useful when applied topically to skin, e.g., anti-inflammation, acne reduction, moisture retention.
In Surinam and some other countries, the tree serves as a windbreak to support vines and as shade for coffee trees.