Guarana , 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 stimulant: 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 colour ranges from brown to red and contains
black seeds which are partly covered by white arils. The colour
contrast when the fruit has been split open has been likened to
eyeballs; this has formed the basis of a myth.
The Guaranís would make a tea by shelling, washing and drying 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, which would be grated and then immersed into
hot water along with sugar.
The table to the right contains a partial listing of some of the
chemicals found in guarana seeds, although other parts of the plant
may contain them as well in varying quantities.
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. The main polyphenols found in guarana are
(+)-catechin and (-)-epicatechin.
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.
Brazil, which is the third-largest consumer of soft drinks in the
world, produces several soft drink brands from guarana extract. The
Portuguese word "Guaraná" is widely used in Brazil as a reference to
soft drinks containing guarana extract. Brazilian sales of guarana
beverages exceed those of cola drinks.
In Peru, Guaraná is a Peruvian brand of soft drink containing
guarana fruit, owned by Backus and Johnston. In 2007 the drink had
5% of the Peruvian soft drinks market, and was relaunched with a new
bottle and label and a light version.A year later its sales had
increased by 49%.
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.
Other uses and side-effects
In the United States, guarana has the status of "generally
recognized as safe".
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