Guarana is a South American fruit that resembles a human eyeball, with dark brown seeds encapsulated by fleshy white fruit. These seeds are about the size of coffee beans. Guarana extract is manufactured by processing the seeds into a powder. For centuries, the Amazonian tribes have consumed guarana for its therapeutic properties, being well known for its stimulant and antioxidant effects. Today, 70% of guarana made is used by the beverage industry in soft and energy drinks, while the remaining 30% is turned into powder1. It’s main secret ingredient? The guarana seeds contain approximately four times the amount of caffeine found in coffee beans2. While coffee holds 2% caffeine by weight, guarana contains between 3.6% and 5.8% caffeine by weight3. In this article, we review the health benefits of this herbal supplement guarana that is found in most bombastically named energy drinks.
Being the chief stimulant in guarana, it has energising effects on the body, relieving fatigue and weakness, according to the European Medicines Agency4. Caffeine ingestion can delay fatigue during exercise by 50-70%5 and boosts the energy expenditure, in other words, metabolism by 8-11% over a period of 12 hours6. A more active metabolism means body burns more calories at rest. As such, guarana contains the properties to promote weight loss. Guarana has demonstrated in another experimental study being responsible for the up regulation of the anti-adipogenic genes Wnt10b, Wnt3a, Wnt1, Gata3 and Dlk1 and down-regulation of pro-adipogenic genes Cebpα, Pparγ and Creb17. In other words, it suppresses genes that aid fat cell production and promotes genes that slow it down.
Being an excellent source of caffeine, it helps maintaining focus and mental performance. Caffeine works through blockade of central nervous system (CNS) by binding at the adenosine receptors5. It has been shown to counteract most of the inhibitory effects of adenosine on neuroexcitability, neurotransmitter release, arousal, and spontaneous activity5. Guarana improved secondary long-term memory performance and increased alertness and content mood ratings (Bond-Lader mood scales) according to a 2007 study8.
Historically, guarana was used to reduce the sensation of pain owing to its high concentration of caffeine content. Caffeine serves an important role in pain modulation, as it attaches and blocks adenosine receptors5. Two of these receptors — A1 and A2a — are involved in intensifying feelings of pain9.
Chronic inflammation is a medical condition illustrated by continued active inflammation response and tissue destruction. Many of the immune cells including macrophages, neutrophils and eosinophils are involved directly or by production of inflammatory cytokine in pathology of chronic inflammation. Inflammatory process activates oxidative stress and decreases cellular antioxidant capacity. Overproduced free radicals react with cell membrane fatty acids and proteins harming their function permanently, causing mutation and DNA damage. This reveals the importance of antioxidant defence system in human body. In addition to caffeine, guarana seeds are known to harbour a number of other possible stimulants such as catachins, tannins, saponins and other alkaloids such as theophylline and theobromine10, making it a herbal supplement rich in antioxidant profile.
Guarana has shown to have decreased cell mortality, lipid peroxidation, DNA damage and cell oxidative stress10. Its consumption is allied with a reduced occurrence of cardiovascular metabolic diseases and has constructive effects on lipid metabolism, largely associated to low density lipoprotein (LDL) cholesterol levels. LDL oxidation is a key initial event in the development of atherosclerosis. This antiplatelet aggregatory activity seen offers health benefits towards lowering risk of thrombosis or formation of blood clot within blood vessel, and subsequently pose protective properties against cardiovascular diseases11.
Last but not least, we will discuss about the chemopreventive effect against carcinogenesis of guarana herb. Cancer, is a disease described by uncontrolled cell growth. Guarana treatment decreased proliferation or cell multiplication by 57.9% and increased death of tumor cells by 4.85-fold, consequently reducing the tumor burden area by 68.6% compared to control group12. The potential anti-cancer properties of guarana derive from its content of xanthines, which are compounds that are similar to caffeine and theobromine.
Guarana has an excellent safety profile being categorised by FDA as generally safe and is widely available. It is worth noting that taken in excess, guarana can produce similar symptoms to a high-caffeine intake including insomnia, anxiety, heart palpitations, increased heart rate and blood pressure, stomach upset etc. Therefore guarana offers an attractive additive to the manufacturers of many popular energy drink formulations for its use can further increase the caffeine content and general stimulant properties obtainable from these beverages.
- Schimpl FC, da Silva JF, de Carvalho Goncalves JF, Mazzafera P. Guarana: Revisiting a highly caffeinated plant from the Amazon. Journal of Ethnopharmacology. Volume 150, Issue 1, 28 October 2013, Pages 14-31.
- Moustakas D, Mezzio M, Rodriguez BR, Constable MA, Mulligan ME, Voura EB. Guarana Provides Additional Stimulation over Caffeine Alone in the Planarian Model. PLoS One. 2015; 10(4): e0123310.
- JK Aronson. Meyler's Side Effects of Drugs: The International Encyclopedia of Adverse Drug Reactions and Interactions, Sixteenth Edition, Seven Volume Set. 2016.
- European Medicines Agency. Paulliniae semen. Accessed on 24/11/2021. https://www.ema.europa.eu/en/medicines/herbal/paulliniae-semen
- Davis JM, Zhao Z, Stock HS, Mehl KA, Buggy J, Hand GA. Central nervous system effects of caffeine and adenosine on fatigue. American Journal of Physiology-Regulatory, Integrative and Comparative PhysiologyVol. 284, No. 2.
- Dulloo AG, Geissler CA, Horton T, Collins A, Miller DS. Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers. Am J Clin Nutr. 1989 Jan;49(1):44-50.
- Da Silva Lima N, de Paula Numata E, de Souza Mesquita LM, Dias PH, Vilegas W, Gambero A, Ribeiro ML. Modulatory Effects of Guarana (Paullinia cupana) on Adipogenesis. Nutrients. 2017 Jun 20;9(6):635. doi: 10.3390/nu9060635.
- Haskell CF, Kennedy DO, Wesnes KA, Milne AL, Scholey AB. A double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans. Controlled Clinical Trial J Psychopharmacol. 2007 Jan;21(1):65-70.
- Baratloo A, Rouhipour A, Forouzanfar MM, Safari S, Amiri M, Negida A. The Role of Caffeine in Pain Management: A Brief Literature Review. Anesth Pain Med. 2016 Mar 26;6(3):e33193.
- Bittencourt LS, Machado DC, Machado MM, Dos Santos GFF, Algarve TD, Marinovic DR, Ribeiro EE, Soares FAA, Barbisan F, Athayde ML, Cruz IBM. The protective effects of guaraná extract (Paullinia cupana) on fibroblast NIH-3T3 cells exposed to sodium nitroprusside. Food and Chemical Toxicology Volume 53, March 2013, Pages 119-125.
- Ravi Subbiah MT, Yunker R. Studies on the nature of anti-platelet aggregatory factors in the seeds of the Amazonian Herb Guarana (Paullinia cupana). Int J Vitam Nutr Res. 2008 Mar;78(2):96-101. doi: 10.1024/0300-98220.127.116.11.
- Fukumasu H, Avanzo JL, Nagamine MK, Barbuto JA, Rao KV, Dagli MLZ. Paullinia cupana Mart var. sorbilis, guaraná, reduces cell proliferation and increases apoptosis of B16/F10 melanoma lung metastases in mice. Braz J Med Biol Res. 2008 Apr;41(4):305-10. doi: 10.1590/s0100-879x2008000400008.