This is a climbing plant in the maple family,
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 and its
seeds contain about twice the concentration of 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 herbivores from the berry and its seeds.
If you look at the contents of any energy drink, chances are that
guarana is listed as one of the main ingredients. European
missionaries in 17th-century Brazil recorded the native people’s
use of the berry, noting that it not only gave them energy, but
allowed them to go for days without feeling hungry. It became a
colonial trading commodity that was said to help protect the body
from illness, but too much of it was known to cause insomnia.
The caffeine that is found in the guarana berry is thought to be
different from the caffeine found in coffee. Guarana contains
chemical components called tannins, which are thought to produce a
longer-lasting effect than caffeine from other sources. For
centuries, guarana berry seeds have been powdered or smoked in a
long process that is done by hand. Drinking properly prepared
guarana can be central to formal occasions and gatherings, where
groups of people pass around a calabash bowl.