Often people hear about guarana in the form of an ingredient behind their fat burning supplement. But to their ignorance, most don’t even question what it is and how it works in the body. Let’s understand about this ingredient.
According to a 2013 study in the Journal of Medicinal Plants Research, by a Brazilian research team, led by L. Hamerski, Guarana is widely used in Brazil for its medicinal properties, but it is also consumed in European countries. This plant is native to the Central Amazon basin and occurs in Brazil, Colombia, Ecuador, Peru, Venezuela and the Republic of Guyana. Roasted seed extracts have been used by natives.
According to a Brazilian research team, led by Leila Larisa Medeiros Marques, in the 2019 study in the Brazilian Journal of Pharmacognosy, for hundreds of years, guarana has been grown and widely used by Brazilian Indians. Commonly, guarana seeds are used by simply dissolving the powder of the toasted and ground seed in water, either alone or in combination with other commercially available herbal drugs. Nowadays, it is commercially exploited, mainly by the soft drinks industry, although it is also highly valued by the cosmetic and pharmaceutical industries.
The Maues Indians in Brazil discovered and named the guarana fruit. They were the first consumers of the guarana beverage. The fruits of guarana are orange-red capsules that contain black seeds, partially covered by white arils. The contrasting colours of the partially open fruit, creates the appearance of eye-balls, thus, giving credence to the legend about the origin of the domestication of guarana. This myth, which is attributed to the Maues Indians, has it that a malevolent god attracted a beloved male child of the village into the jungle and killed him out of jealousy. The people of the village found the child dead, lying in the forest. A benevolent God consoles the village with a present in the form of guarana. He plucked out the left eye of the child and planted it in the forest, where it became the wild variety of guarana. The right eye was planted in the village, and it sprouted and produced fruits that resembled a child’s eye.
The first written description of guarana was made by a Jesuit missionary named Johannes Philippus Bettendorf (1625–1698), in 1669. As a missionary in the Amazon region, he observed that the Indians used to consume a drink made of guarana, which they reported as having diuretic properties and being effective against headaches, fevers, and cramps. In the mid-18th century, other reports described the use of guarana against diarrhoea and its ability to mitigate the risks of heat stress.
The first substance of guarana was isolated in 1826 and named guaranine, a tetramethylxanthine identical to caffeine. The stimulating effects of guarana are apparently more lasting than the effects of coffee due to the tannins present in the guarana plant.
According to L. Hamerski, Amazonian tribesmen as an herbal beverage, based on its reputation as a stimulant, aphrodisiac, and tonic for headaches. Recently, it has been shown to promote weight loss to improve cognitive performance. It is used for its antidepressant, antioxidant, and antibacterial effects. It is also an ingredient in some soft drinks, non-alcoholic beverages and cosmetics.
Chemically, Guarana seeds mainly consist of methyl-xanthine derivatives, including caffeine, theophylline and theobromine, which have well-studied effects on the central nervous system. It also contains a high proportion of polyphenols and catechins. It is counted as one of the most promising drugs of Brazilian flora.
An extensive range of products that include Guarana seed extracts as ingredients is commercially available. Examples include confections (e.g., chocolate products), fruit-juice-based drinks, “energy drinks”, dietary supplements, cosmetics, and most controversially, natural weight loss products.
Guarana is classified as a thermogenic agent (a metabolic stimulant), because of its caffeine contents. Energy drinks typically comprise high levels of caffeine, as the dose of caffeine from high-energy drinks is typically up to 500mg. Guarana, taurine and sugar with various other amino acids are often also included in these formulations. Guarana is reported to have the highest concentration of caffeine (more than 6% in the seeds) observed in nature so far.
Guarana seed extract exhibits a powerful antioxidant activity, and in combination with vitamins and minerals, it improves cognitive task performance and attenuates increased mental fatigue associated with extended cognitive task performance.
Guarana seed products are increasingly being used as a weight loss product in the form of powder, tablets, etc. and it is widely consumed by athletes who believe that it presents ergogenic and “fat-burning” effects.
A Slovenian research team, led by Lucija Majhenic, in a 2007 study in the journal Food Chemistry, suggested that the seed extracts of Guarana possess strong antimicrobial and antioxidant properties and can, therefore, be used as a natural additive in cosmetics, foods and pharma industry.
In the United States, guarana fruit powder and seed extract have not been determined for status as “generally recognized as safe” (GRAS) by the Food and Drug Administration, but rather are approved as food additives for flavour uses.
Brazil is virtually the sole producer of guarana in the world. Guarana is widely used in the food industry in the form of syrups, extracts, and distillates, primarily as a flavouring agent and as a source of caffeine by soft drink manufacturers.
The guarana plant is a lowland, tropical, woody, climbing shrub, which is adapted to a hot and humid climate.
Guarana seeds are the commercially useful part of the plant because of the large amounts of caffeine (40–80mg caffeine per gram guarana extract), theobromine, and theophylline, as well as the high concentration of tannins and other compounds, such as saponins, polysaccharides, proteins, fatty acids and trace elements, such as manganese, rubidium, nickel and strontium.
Guarana powder is a product easily available both in natural product stores and over the internet. It is either marketed alone or in combination with other herbal drugs, creating the likelihood of additive or synergistic effects. It is also included in a variety of energy drinks.
A series of adverse events are associated with the consumption of it including irritability, heart palpitations, anxiety, disorders of the central nervous system and myoglobinuria
Guarana can also exacerbate epileptic seizures, lowering the seizure threshold or increasing the duration of seizures. Despite these reports, when taken alone, guarana has few adverse effects and the majority of them are similar to those observed after the consumption of products containing high caffeine content.
As a result of its methylxanthine content, the guarana extract can block adenosine and phosphodiesterase inhibitors, thereby, increasing noradrenaline activity.
In a 2017 study in the journal Medicines, a German research team, led by Herbenya Peixoto, investigated the anti-aging and antioxidant activity of guarana. Researchers also evaluated a potential protective effect of the guarana extract against induced oxidative stress and its influence on the cellular accumulation of reactive oxygen species (ROS).
Researchers found that, extract from roasted guarana seeds enhanced resistance against oxidative stress, extended lifespan and attenuated aging markers such as muscle function decline. Thus, it apart from being a fat burner can also be used as an antioxidant and has anti-ageing properties.
In a 2013 study in the Journal of Negative Results in BioMedicine, an Italian research team, led by Gianluca Ivan Silvestrini, assessed the effects on psychological well-being, anxiety and mood of a commercially available guarana preparation taken regularly over several days according to the labeled dosages and instructions, in 27 healthy volunteers. Guarana 350mg × 3 daily just after breakfast or placebo were given for 5 consecutive days. However, its supplementation provided no evidence for any major effects on psychological well-being, anxiety and mood.
In a 2017 study in the journal Nutrients, a Brazilian research team, led by Natalia da Silva Lima, found that guarana modulates the expression of several genes associated with adipogenesis, and thus has an anti-adipogenic potential. Adipogenesis is the formation of adipocytes (fat cells) in the body.
According to a 2013 study in the Journal of Ethnopharmacology, by a Brazilian research team, led by F.C. Schimpl, guarana is primarily produced in the Brazilian states of Amazonas and Bahia, and approximately 70% of the production is used by the industry of soft and energy drinks. The other 30% becomes guarana powder for direct consumption in capsules or dilution in water, or it serves as a raw material for the pharmaceutical and cosmetics industries.
In a 1996 study in the Sao Paolo Medical Journal, Brazilian researchers J.C. Galduroz & E.A. Carlini assessed the effects of the long-term administration of guarana on the cognition of normal, elderly volunteers. Forty-five volunteers were studied, divided into three groups: placebo, caffeine, and guarana. Researchers found no significant cognitive alterations in these elderly subjects.
In a 2007 study in the Journal of Psychopharmacology, a British research team, led by C.F. Haskell, assess acute, dose-related behavioural effects of an extract of guarana plant for the first time in 26 human subjects, throughout the day of four different doses (37.5mg, 75mg, 150mg and 300mg). Guarana improved memory performance and increased alertness and mood. The two lower doses produced more positive cognitive effects than higher doses. The findings suggest that the effects cannot be attributed to caffeine alone.
In a 2009 study in the Journal of Alternative and Complementary Medicine, a Brazilian research team, led by V. da Costa Miranda, evaluated the effectiveness of guarana in the treatment of post-radiation depression and fatigue, in 36 patients with breast cancer undergoing radiation therapy, who were given 75mg guarana or placebo, daily for 28 days.
Researchers in the study was unable to show any statistically significant differences between the guarana and the placebo-treated group. Thus, patients with breast cancer undergoing radiation therapy didn’t derive any advantage with guarana over placebo for both fatigue and depressive symptoms.
In a 2005 study in the journal Clinical Pharmacology & Therapeutics, a US research team, led by C.A. Haller, determined whether repeated dosing and multi-ingredient formulations contribute to the adverse effects of these supplements, containing ephedra and guarana. In this study, 16 healthy adults (8 women) took 2 doses each of ephedra-guarana alone, Xenadrine RFA, a multicomponent dietary supplement containing 25mg ephedra alkaloids and 200mg caffeine, or placebo 5 hours apart.
Researchers found that consumption of 2 doses of ephedra and guarana supplements, per supplement label recommendations, results in persistent increases in heart rate and blood pressure and unfavourable actions on glucose and potassium homeostasis. Such effects could be detrimental in persons with hypertension, atherosclerosis, or glucose intolerance, conditions that are strongly associated with obesity.
In a 2001 study in the International Journal of Obesity & Related Metabolic Disorders, a US research team, led by C.N. Boozer, examined in overweight humans the short-term safety and efficacy for weight loss of an herbal supplement containing Ma Huang, Guarana and other ingredients (72mg/day ephedrine alkaloids and 240mg/day caffeine), for 8 weeks. The subjects were divided into the supplement group or the placebo group.
Researchers found that Active treatment produced a significantly greater loss of weight and fat over the 8-week treatment period than did placebo. Active treatment also produced greater reductions in hip circumference and serum triglyceride levels. Eight of the 35 actively treated subjects (23%) and none of the 32 placebo-treated control subjects withdrew from the protocol because of potential treatment-related effects. Dry mouth, insomnia and headache were the adverse symptoms reported most frequently by the herbal vs the placebo group.