Guarana comes from the Amazon basin, and has been used by the natives of the Amazon rain forest to treat conditions such as diarrhea, arthritis, fatigue and even to reduce hunger. It is, in fact, a climbing plant of the Sapondacaea family, although it is the fruit for which it best known. Each contains a single seed that contains around five times the amount of caffeine of a similarly sized coffee bean.
An interesting piece of trivia is that the reason why such seeds are rich in caffeine is that the substance is poisonous to certain pathogens that would otherwise attack the berry. The same is - true of all seeds that contain caffeine: it is a means of self-defense. Obviously it is an effective defense since the berries appear to relatively immune to such common plant diseases.
Guarana is named after the Guarani tribe of South America, and the language is spoken by many in the area around Paraguay, Bolivia and Brazil, and also parts of Argentina. In fact over 67% of Paraguayans speak the language. There is a myth that when child of the Guarana village was killed by an evil god, a more benevolent deity planted the child's left eye in the forest and the right eye in the village. The left eye gave rise to the wild form of the plant, and the right eye the cultivated form.
This likely came about because of the appearance of the fruit when it is split open: it has the appearance of eyeballs. However, what is true is that Guaranis made tea from the seeds, and also a bread known as guarana bread by mashing the powder into a dough and shaping it into a cylindrical bread. It is dry roasted and milled to a fine powder, also known as Brazilian cocoa, but it has never quite managed to compete commercially against the coffee! However, it has its local adherents to whom it is a staple drink.
However, back to the health benefits of the seed. They were recognized as early as the 17th century when Father Felip Betendorf introduced it into Western civilization, but over the centuries since then it has been found that even in spite of the caffeine content it has been demonstrated to have brain-boosting properties and able to increase tasks requiring mental attention. It is certainly known to be an energizer, and able to give a boost to your brain when you really need it. So why should this be, and how does it do this?
The flavor is a bit like chocolate, hence its nickname of Brazilian cocoa, and has been approved by the FDA as a food additive. Extracts from the berry have been shown to possess strong antioxidant properties, and also act as bactericides and fungicide, few of which can be put down the caffeine content. In fact the seed has been proposed for use in the food industry as a natural antioxidant and preservative and as stated below, that is more acceptable to people than synthetic chemicals.
This is probably in response to the fact that synthetic antioxidants are in decline whereas the natural antioxidants such as vitamins, C and E and the various tocopherols and carotenoids are increasing in prominence due to them being more readily accepted by the consumer than the synthetics such as butylhydroxytoluene(BHT). These antioxidants are commonly used as food preservatives, in that they slow down the oxidation of foodstuffs, and people are increasingly feeling that natural products are preferable for this application than synthetic.
Guarana seeds have been found to be exceptionally high in proanthocyanadins with powerful antioxidant properties. They are fatal to free radicals and help to prevent cardiac disease and to improve cellular activity. They also display antimicrobial and antifungal activity. Chemically, they consist of up to 60% starch, pectins, saponins, proteins, and the aforementioned caffeine (3% - 5%). The guarana paste can contain up to 7% caffeine that can be dangerous to those with cardiac problems.
Guarana also contains tannins at levels of up to 12%, including catechin and some proanthocyanadins. The astringency of these tannins represents a problem to their use in the beverage and food industry, although the substance is regarded as safe by the FDA. They have little if any nutritional value and can react with alkaloid and proteins to form unwanted complexes. Were it not for tannins guarana would be more acceptable to the food industry.
However, it is for their energy-boosting properties that the guarana berries and seeds are most prized by many. The fact they it has been traditionally used as a stimulant and aphrodisiac indicates that there is something behind these claims. Studies on mice, hamsters and other animals have supported these effects. It has been found to posses the two desirable properties (to some) of stimulating the nervous system and curbing the appetite.
Consequently, it is used in diet and weight loss pills, and also to maintain high energy levels. In fact weight loss pills are used by many people to maintain their energy levels while not eating. This is a definite bonus to those that want to lose weight, but dislike the lethargy that a strict diet can cause.
There is a downside to that of course, and that is insomnia and an increased heartbeat, and also nervousness and feeling 'on edge'. Once people stop using guarana they suffer withdrawal symptoms such as nervousness, irritability and headaches.
The upshot is that it is basically the high caffeine content of guarana that allows its use as a stimulant that can boost not only energy, but also reduce appetite and act as an effective weight loss supplement. However, used excessively it can lead to nervousness and while it is included as an ingredient in many foods and drinks, you should be careful when using it as an energizing supplement if you have any heart problems at all.
Otherwise, guarana is used to energize the body naturally, and is not only very commonly used for this purpose in South America, but also increasingly so in the USA and elsewhere with some very good results.