Guarana extracts are derived from the seeds of a Brazilian vine, Paullinia cupana. It is named after the Guarani people of the rain forest who roast the seeds to brew a traditional, coffee-like, stimulating drink. Known locally as the ‘food of the gods’, guarana berries have an extraordinary appearance that resembles an eye as the white coated seeds burst from the scarlet fruit.
Guarana health benefits
Guarana seeds contain a complex of natural alkaloid stimulants similar to those found in coffee, including caffeine (a trimethyl xanthene) and guaranine (a tetramethyl xanthene). The concentration of caffeine within guarana seeds is over 6%, and is higher than that found in coffee beans – in fact, guarana seeds have the highest concentration of caffeine found in any natural source.
Guarana seed extracts also contain saponins similar to those found in Panax ginseng, and the two supplements are often combined together. Guarana also provides powerful antioxidant catechins related to those found in green tea, as well as unique flavonoid antioxidants that are not found anywhere else in nature.
The combination of all these active ingredients make guarana an energising supplement that acts as a nootropic to improve clarity of thought, lifts mood, and stimulates the metabolism to increase fat burning. As a result, Guarana is used as a weight loss supplement, and to reduce fatigue.
Research in roundworms shows that guarana antioxidants have significant anti-ageing effects and significantly extended their lifespan by 14%. Whether or not it can do the same for us is still under investigation!
Guarana and alertness
The concentration of caffeine in guarana seeds is twice that found in coffee beans. As the caffeine is buffered by the saponins present, it is absorbed more slowly to provide longer energy boost than pure caffeine.
Guarana alkaloids do this through effects on enzymes (cAMP phosphodiesterases) and adenosine receptors in the brain, which increase mental alertness, physical performance and reduce perceptions of fatigue.
Guarana is traditionally used to increase alertness, energy levels and responses to stress. Research shows that, compared with placebo, taking a guarana extract produces greater improvements in memory, concentration and the ability to think straight (cognition) during challenging mental tasks.
In one study, the effects of different doses on mood and cognition were tested, using 37.5 mg, 75 mg, 150 mg and 300 mg of a standardised guarana extract. All doses of Guarana improved memory performance, increased alertness and improved mood ratings compared with placebo. Interestingly, the two lower doses of Guarana produced more positive cognitive effects than the higher doses, and could not be attributed to the level of caffeine present, alone.
Guarana and weight loss
The metabolic stimulants present in guarana include caffeine, guaranine and antioxidant catechins. Researchers have found that guarana extracts activate fat burning genes and reduce fat storage, as well as lowering blood triglyceride levels by increasing their uptake into cells for burning as fuel. Guarana is under active investigation as a potential new, anti-obesity treatment,
Guarana is found in one of the best researched weight loss supplements, Zotrim, in combination with two other South American herbs, Damiana and Yerba Mate. This combination of herbs slows stomach emptying to reduce hunger and stimulates fat burning.
A group of 73 overweight UK nurses who took Zotrim for 10 weeks lost 3kg in weight. Overall, 85% said they would recommend Zotrim to their friends while 47% would recommend it to their patients.
Guarana and heart health
Laboratory studies suggest that guarana has an anti-platelet action and may offer health benefits in reducing the risk of unwanted blood clots (thrombosis) and cardiovascular disease.
Guarana and asthma
Guarana naturally contains substances that act as bronchodilators, to relax the airways and improve breathing. A typical guarana extract provides 100mg/gram caffeine, 2mg/gram theophylline, and 1mg/gram theobromine. These ingredients are all used to treat asthma. A gold-standard Cochrane review concluded that, in people with asthma, caffeine improves airway function for up to four hours. Even at low doses, caffeine can improve lung function for up to 2 hours afterwards. This suggests that taking guarana may offer benefits for people with asthma, but check with your doctor first if you are on medication. NB Don’t take coffee or guarana for at least 4 hours before a lung function test as this could result in misinterpretation of the results (showing them as better than they usually are).
Guarana and jet lag
Guarana is used to prevent jet lag, and is best taken before, during and after a long-distance flight. I use it when flying abroad and find it works brilliantly when I need to stay alert on arrival.
Guarana and fatigue
Guarana is especially popular among athletes to overcome post-exercise fatigue, but if you take part in competitive sport subject to blood testing, check first whether or not caffeine or guarana is a banned ingredient as regulations do change. Caffeine use is currently being monitored by WADA (the world anti-doping agency). To check whether a substance is banned for your sport, CLICK HERE.
For alertness, a dose of 35mg to 75mg guarana extract can have beneficial effects.
To promote weight loss and reduce fatigue, a typical dose is 500mg to 1g a day, which can be taken in divided doses, before meals, or as one dose.
Guarana side effects
Guarana contains caffeine which, in high doses, cause overstimulation.
If you have high blood pressure, keep a close eye on your readings when taking guarana in case your hypertension is sensitive to the effects of caffeine.
Interestingly, the slow release of these stimulants mean that guarana does not disrupt sleep, for most people, in the same way as having a strong cup of coffee. However, some people are sensitive to caffeine in all its forms, and the effects on sleep appears to be an individual response.
Do not exceed manufacturer’s recommended doses as concentrations vary between brands.
Image credit: anita.fortis/wikimedia