Guarana or Guaraná (,  or ), Paullinia cupana (syn. P. crysan, P. sorbilis), is a shrub or small tree in the Sapindaceae family. It is native to Venezuela and northern Brazil. The seed of the Guaraná fruit is a stimulant with thermogenic and diuretic properties.

The guaraná fruit's color ranges from orange to red and contain 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 (see below).

Guaraná plays an important role in Tupi and Guaraní Brazilian culture. The name 'guaraná' is derived from the Tupi-Guarani word wara'ná. These tribes believed, it was magical, a cure for bowel complaints and a way to regain strength. They also tell the myth of a 'Divine Child' that was killed by a serpent and whose eyes gave birth to this plant.

Uses
Guaraná is mainly used as an ingredient in soft drinks and energy drinks. It is also used as a dietary supplement, generally to promote weight loss. In addition, it may be an ingredient in other foods.

Beverages
In addition to other chemicals, the guaraná plant contains caffeine (sometimes called "guaranine"), theophylline, and theobromine. Water extracts of the guarana plant are central nervous system stimulants due to the content of these alkaloids. Energy drink manufacturers typically add synthetic caffeine or caffeine derived from coffee decaffeination, though many advertise "natural" caffeine from the seeds of guaraná.

Brazil produces several brands of soft drink from guaraná extract that contain no added caffeine. Each differs greatly in flavour; some have only a slight guaraná fruit taste.  They are typically fizzy and sweet, with a very fruity aftertaste. Most guaraná drinks are produced in Brazil and consumed locally or in nearby countries, such as Paraguay. Major brands include Guaraná Antarctica, Guaraná Schin from Schincariol and Guaraná Brahma from AmBev, Kuat, and Guaraná Jesus, a local Brazilian brand named for the druggist that formulated it. Many local producers also create drinks not for export.

Using it to lose weight

Studies involving guaraná show benefits to cognitive function. They have not been evaluated by the Food and Drug Administration (FDA) or any similar government agencies. In the United States, guaraná holds a GRAS-status, i.e. generally regarded as safe and must be labeled as not intended to diagnose, treat, cure or prevent any disease.

The Journal of Human Nutrition and Dietetics published a study in June 2001. This study shows  an average 11.2 pound weight loss in a group taking a mixture of yerba mate, guaraná and damiana, compared to an average 1 pound loss in a placebo group after 45 days.

A university study in Brazil of guaraná extract showed a platelet aggregation decrease of up to 37% of control values and a decrease of platelet thromboxane formation from arachidonic acid of up to 78% of control values. This study may be significant to stroke and heart attack risk reduction because when excess thromboxane formation occurs, an arterial blood clot can develop, resulting in a heart attack or ischemic stroke.

A separate 1997 study of guaraná's effects on the physical activity of rats showed increased memory retention and physical endurance when compared with a placebo.

Other studies have shown antioxidant, antibacterial, and fat cell reduction (when combined with conjugated linoleic acid) properties in guaraná 

Although side-effects of guaraná are rare, drugs.com recommends, "When considering the use of herbal supplements, consultation with a primary health care professional is advisable. Additionally, consultation with a practitioner trained in the uses of herbal/health supplements may be beneficial, and coordination of treatment among all health care providers involved may be advantageous". Drugs.com also advises not to mix guaraná with ephedrine.

What guarana is made of
Guaraná seeds consist of mostly reddish vegetable fiber and resin with a small amount of oil and water. Guarana contains different amounts of caffeine, theobromine, theophylline and other alkaloids, compared to coffee, tea, mate, or cocoa.

(*) ppm = parts per million
tr = trace

Duke1992a: Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.

Guaranine and caffeine
The chemical "guaranine" is identical to caffeine coming from other sources, for example coffee, tea and mate. Guaranine, theine, mateine are all official synonyms for caffeine.

Other websites
 Guaraná Home Page 
 Raintree Tropical Plant Database: Guaraná
 Other information from an herbal supplements site
 Duke's Database 
 USDA Database

Footnotes 

Sapindaceae
Fruits