The plant Guarana is a member of the maple family. It is generally grown in South America. Most energy drinks today contain some from of guarana due to its high concentration of caffeine. The high caffeine content also makes guarana a great diuretic – it has also been tested as a dietary supplement because of its caffeine content, but the research was inconclusive. Guarana can be found in capsule, liquid and tablet form.
The medicinal parts are the peeled, dried, roasted, and pulverized seeds, formed into a thick paste with water.
Flower and Fruit
The usually unisexual flowers are inconspicuous, yellow to whitish, and fragrant. They are in 30 long panicles, which only produce female or male flowers at any one time. The fruit is a hazelnut-sized, deep yellow to red-orange, trisectioned capsule, which bursts open when ripe and releases 1 purple-brown to black seed in a cuplike aril.
Leaves, Stem, and Root
The plant is a woody, evergreen perennial vine up to 10 m long, which climbs through the jungle. It is bushier in its cultivated form. The leaves are large, palmate, coriaceous, distinctly ribbed, and roughly crenate-serrate.
A paste is formed from the pulverized and roasted seeds, formed into rolls or bars, and dried. The taste is astringent, bitter then sweet, and the odor is reminiscent of chocolate.
The plant is indigenous to the Amazon basin and has been introduced into other rain forests. The main area of cultivation is between Maues and Manau in Brazil.
Guarana seeds are the seeds of Paullinia cupana. A preparation is also made from the ground seeds. Over a period of approximately 75 days, the pollinated flower develops a “ripe” guarana raceme, which is harvested by hand from October to December. Seeds (up to 80 per raceme) are taken out of the capsule shells, soaked for a time in water and then finally separated from the arillus. Subsequent to being dried in the sun, the seeds are roasted for 2 to 3 hours in special clay ovens. Once they have cooled, the parchmentlike shell is removed and the seeds are ground down. Following this, the resulting paste is smoked over aromatic charcoal. The final product is dark brown in color and in stick form.
Brazilian Cocoa, Guarana Bread, Paullinia
Actions & Pharmacology
Purine alkaloids: chief alkaloid caffeine (3.6-5.8%), in addition, small amounts of theophylline and theobromine
Tannins (12%): oligomeric proanthocyanidins, condensed tannins
Cyanolipides: including among others, 2,4-dihydroxy-3-methylene-butyronitrile
Guarana produces a stimulating effect, due to the presence of purines (caffeine, theobromine, theophylline). Caffeine is centrally stimulating, has a positive inotropic and, in high concentrations, has a positive chronotropic cardiac effect. It relaxes the vascular muscles (with the exception of cerebral vessels that constrict) and the bronchial tube.
Caffeine works as a short-term diuretic and increases gastric secretion. Furthermore, it increases the release of catecholamines. Inhibition of blood platelet aggregation has been observed.
A double-blind, parallel, placebo-controlled trial of yerba mate, guarana, and damiana (YGD) was conducted on 47 healthy volunteers, aged 20 to 60, to evaluate the effects on gastric emptying and weight loss. Subjects, who had body weight taken and ultrasound performed, were instructed to fast for 8 hours prior to the study start. They were then given three YGD capsules, each containing 112 mg yerba mate, 95 mg guarana, and 36 mg damiana extract, to ingest with 20mL of apple juice, and 15 minutes later, with 400mL of apple juice. The subjects were evaluated at 10 and 45 days. The mean gastric emptying times were 38 ± 7.6 minutes following placebo capsules and 58 ± 15 minutes after YGD capsules (a mean 53% increase). Subjects in the treatment group showed an increased weight loss (mean decrease of 5.1 ± 0.5kg after 45 days on YGD vs. 0.3 ± 0.08kg with placebo). The active treatment was a combination product with each constituent having its own potential to cause weight loss (Andersen, 2001).
An herbal supplement containing principally 600 mg black tea extract (60 percent polyphenols, 20 percent caffeine) and 442 mg guarana extract (36 percent caffeine) was tested for stimulation of thermogenesis. A double-blind, placebo-controlled, crossover study was conducted on 16 healthy, weight-stable, non-smoking subjects, aged 21-55 years, with body mass index (BMI) of 20-30 kg/m2, and not taking any medications other than oral contraceptives or hormone replacement therapy. Subjects had no caffeine for 48 hours, no exercise for 24 hours, and no food for 12 hours before each visit. Area under the curve (AUC) for resting metabolic rate (RMR), respiratory quotient (RQ), blood pressure, pulse rate, and temperature were measured. At each visit RMR was measured at baseline and at one and two hours following oral administration of supplement or placebo. The RMR and systolic blood pressure (SBP) AUCs increased significantly (p<0.02 and p<0.01, respectively) in the herbal supplement group compared to placebo. The AUC increase in RMR over the two-hour test period was 77.19 kcal/24 hr2 ± 120.10 kcal/24 hr2 with an average rise of 52.38 ± 29.52 kcal/24 hrs. The AUC rise in SBP over two hours was 10.3 mm Hg/hr ± 14 mm Hg/hr. The average rise in SBP over two hours was 3.7 mm Hg ± 4.4 mm Hg. The herbal supplement increased metabolic rate without changing substrate oxidation. The rise in SBP was consistent with the amount of caffeine the supplement contained (Roberts, 2005).
The effect of a mixture of green tea and guarana extracts containing a fixed dose of caffeine and variable doses of epigallocatechin-3-gallate (EGCG) on 24-hour energy expenditure and fat oxidation was examined. Fourteen subjects took part in this randomized, placebo-controlled, double-blind, cross-over study. Each subject was tested 5 times in a metabolic chamber to measure 24-hour energy expenditure, substrate oxidation, and blood pressure. During each stay, the subjects ingested a capsule of placebo or capsules containing 200 mg caffeine and a variable dose of EGCG (90, 200, 300 or 400 mg) three times daily, 30 min before standardized meals. Twenty-four hour energy expenditure increased significantly by about 750 kJ with all EGCG-caffeine mixtures compared with placebo. No effect of the EGCG-caffeine mixture was observed on lipid oxidation. Systolic and diastolic blood pressure increased by about 7 and 5 mmHg, respectively, with the EGCG-caffeine mixtures compared with placebo. This increase was significant only for 24-hour diastolic blood pressure. The increase in 24-hour energy expenditure with the EGCG-caffeine preparation was similar with all doses of EGCG in the mixtures (Berube-Parent et al, 2005).
In a double-blind, counterbalanced, placebo-controlled study of 28 healthy participants aged 18 to 24, the cognitive and mood effects of single doses of guarana, ginseng, a combination of the two, and placebo were assessed. Each sibject received 150 mg guarana dry extract, standardized to 11-13% alkaloid concentration, or 400 mg ginseng extract G115, or a guarana/ginseng combination, or placebo per day. Compared to placebo, the three treatment groups showed improved task performance throughout the day. Guarana showed significant improvements across “attention” tasks and on sentence verification, but with some degree of reduced accuracy. Guarana and the ginseng/guarana combination, and ginseng to a lesser extent, showed improvements in serial subtraction task performance. The ginseng and ginseng/guarana combination enhanced the speed of memory task performance without significant accuracy deficiencies. The effects of the guarana are believed to not be attributed to the caffeine content (Kennedy, 2004).
Euphytose (EUP), a combination of Crataegus, Ballota, Passiflora, Valeriana, Cola, and Paullinia, was examined in a multicenter, double-blind, placebo-controlled general practice study on outpatients with adjustment disorder with anxious mood. Ninety-one patients were included in the EUP group and 91 patients in the placebo group. All received two tablets, three times a day, over 28 days. Evaluation using the Hamilton-anxiety (HAM-A) rating scale were carried out on days 0, 7, 14, and 28. Comparing the two groups, 42.9% of the patients (EUP group) had a HAM-A score of less than 10 at day 28 versus 25.3% in the placebo group (P = 0.012). From day 7 to day 28, there was a statistically significant difference (P = 0.042) between the two treatments, indicating that EUP is better than placebo in the treatment of adjustment disorder with anxious mood (Bourin, 1997).
Indications & Usage
Guarana is used as a tonic for fatigue and to quell hunger and thirst, for headache and dysmenorrhoea, digestion problems, fever, and as a diuretic. Its effect in stimulating the circulation, heart, and diuresis can be explained by the caffeine content.
Precautions & Adverse Reactions
No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages. Quantities corresponding to up to 400 mg caffeine per day (7 to 11 g of the herb), spread out over the day, are toxicologically harmless to a healthy adult habituated to caffeine through regular consumption of coffee or black tea. The quantities of caffeine considered harmless are calculated to include all of the foodstuffs and beverages containing the substance (including coffee, tea, cola, etc.). Caution is advised for patients with sensitive cardiovascular systems, renal diseases, hyperthyroidism, increased tendency to spasms, and certain psychic disorders such as panic anxiety.
With excessive use, however, the diuretic action of Guarana may lead to hypokalemia. Hypokalemia may increase digoxin toxicity.
When taken concomitantly with other drugs, the caffeine in Guarana may result in unwanted outcomes, such as enhanced CNS stimulation or a reduction of the effectiveness or the bioavailability of the drug.
Pregnant women should avoid caffeine, and under no circumstances exceed a dosage of over 300 mg per day.
Infants whose nursing mothers consume caffeine products may suffer from sleeping disorders.
The first symptoms of poisoning are dysuria, vomiting and abdominal spasms.
Mode of Administration
The seeds of Paullinia cupana are grated and taken directly as powder or diluted in water or juice as a drink. It is not in use as a drug. It is available in various medicinal preparations.
- Capsules – 200 mg
- Liquid – 1:1
- Tablets – 800 mg, 1000 mg
Average single dose: 1 g of the powder
5 drops, 10 globules every 30 to 60 minutes (acute) or 1 to 3 times a day (chronic); parenterally: 1 to 2 mL sc, acute: 3 times daily; chronic: once a day (HAB34)